p270: the application of line loss factors to gsps that ... · make provision for the assignment of...
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What stage is
this document in the process?
185/04
P270
Draft Modification Report
8 July 2011
Version 0.3
Page 1 of 12
© ELEXON Limited 2011
Stage 04: Draft Modification Report
P270: The Application of Line Loss Factors to GSPs that are not Transmission-interconnected
The BSC does not permit application of a Line Loss Factor to a Grid Supply Point, including Offshore Transmission Connection Points, a GSP type introduced by the OFTO arrangements.
P270 proposes that distinction should be made between GSPs
based on how they are interconnected with the Transmission
System and LLFs should be applied to GSPs in specific
circumstances.
The Panel recommends Rejection of P270 Proposed Modification
High Impact: None
Medium Impact: LDSOs, Transmission Company, CDCA
Low Impact: Suppliers and embedded generators (via LLF and GSP Group Correction effects) all Parties (via Transmission Losses), ELEXON
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Contents
1 Summary 3
2 Why Change? 5
3 Proposed Solution 6
4 Impacts & Costs 7
5 Implementation 7
6 The Case for Change 8
7 Panel Discussions 9
8 Consultation Responses 10
9 Recommendations 12
10 Further Information 12
Attachment A: Detailed Assessment 12
Attachment B: Legal Text Proposed 12
Attachment C: BSCP25 Redlined Changes 12
Attachment D: BSCP75 Redlined Changes 12
Attachment E: BSCP128 Redlined Changes 12
About this document:
This document is the P270 Draft Modification Report, updated following the P270 Report
Phase industry consultation for presentation to the Panel on 14 July 2011. The Panel will
consider the consultation responses received and the recommendations of the updated
report and agree a final view on whether P270 should be made. The final Modification
Report will then be produced and sent to the Authority for decision.
Any questions?
Contact: Dean Riddell
dean.riddell@
elexon.co.uk
020 7380 4366
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8 July 2011
Version 0.3
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1 Summary
Why Change?
The BSC does not allow a Line Loss Factor (LLF) to be assigned to a Grid Supply Point
(GSP). LLFs are assigned to Boundary Points Metering Systems to account for the losses
considered to be caused, or relieved, on a Distribution System by a flow at that Boundary
Point. A GSP connects a distribution system to the Transmission System and is not
considered a user Boundary Point. P270 contends that LLFs should also be assigned to
GSPs that connect electrically isolated elements of the Transmission System to a
Distribution System.
P270 contends that under the current BSC baseline the flow to a Distribution System from
an Offshore Transmission Connection Point will distort the cost reflectivity of losses
allocated to other Distribution System users, and that the System Operator does not have
visibility of the full impact of offshore networks that connect to a Distribution Systems
upon the losses of that Distribution System.
Solution
P270 proposes that the BSC distinguish between GSPs based on the interconnection of the
Transmission System to which they are connected and provide for LLFs to be assigned to
appropriate GSPs. This would be accomplished by adding and amending BSC definitions.
In effect, a volume of Distribution System losses (including where the connection relieves
losses) would shift from the other Distribution System users into aggregated Transmission
Losses.
Impacts & Costs
Beside the necessary Code changes, relatively minor supporting changes to several BSCPs
would be required. P270 would have a minimal impact on ELEXON and the CDCA service
provider and would not impact central systems. Affected LDSOs would need to amend
their LLF methodologies and determine LLFs for Remote GSPs. Transmission System users
would be impacted by the consequential effect on calculated Transmission Losses. No
significant direct impact on BSC Parties’ systems or processes has been identified.
Implementation
The group recommends that the Implementation Date of P270 should be ten working days
after a decision is received from the Authority.
The Case for Change
P270 contends that remote GSPs differ from GSPs connected to the main, interconnected
Transmission System (which flexibly supply electricity to meet the needs of the Distribution
System), and are more similar to Distribution System users, because such isolated GSPs
use the Distribution System as a means of dispersing electricity flowing from the remote
network to which they are connected.
A key question is whether it is justifiable to shift the effect of Distribution System losses
into Transmission Losses where they result from the operation of an electrically isolated
Transmission System element. The Proposer argued it would promote cost reflectivity in
the allocation of losses, but the majority of the group believed it was not appropriate.
The majority of respondents to the Report Phase Consultation agreed with the Panel’s
views, and there was unanimous support for the legal text and proposed Implementation
Date. The draft BSCP changes were supported by all respondents who gave a view.
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Recommendations
The Panel’s unanimous initial view was that P270 is neutral against Objectives (a), (b), and
(d) and would have a negative impact against Objective (c). The Panel supported the
views and arguments of the majority of the P270 Workgroup.
We recommend that the Panel should confirm its initial recommendation that P270
Proposed Modification should not be approved.
Applicable BSC Objectives
a) The efficient discharge by the licensee [i.e. the Transmission Company] of the
obligations imposed upon it by the Transmission Licence
b) The efficient, economic and co-ordinated operation of the national transmission
system
c) Promoting effective competition in the generation and supply of electricity, and
(so far as consistent therewith) promoting such competition in the sale and
purchase of electricity
d) Promoting efficiency in the implementation and administration of the balancing
and settlement arrangements
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2 Why Change?
A flow of electricity from a relatively isolated GSP (a Remote GSP for the purposes of
P270) onto a Distribution System must physically have some Distribution System losses
associated with it (i.e. some energy is lost in transmission from the point of connection to
the Distribution System to other point(s) on the Distribution System). Additionally, flows
can be considered to reduce losses when taken in the context of the configuration and
operation of the Distribution System as a whole (e.g. where a flow offsets another flow
that would have resulted in greater overall Distribution Losses). However, this is also true
for ‘conventional GSPs’, i.e. GSPs connected to the main, interconnected Transmission
System.
An issue for P270 is whether there is any justification for differentiating between GSPs
based on how they are interconnected (or not) with the rest of the Transmission System,
and then treating GSPs differently with regard to Distribution System losses by allowing
LLFs to be applied to the metered flows of some GSPs. P270 also raises a question around
which participants it is justifiable for the effects of Distribution System losses to fall upon.
The main arguments for and against P270 are summarised below.
Argument for P270
A Line Loss Factor should be applied to a Remote GSP because it behaves differently to a
‘conventional’ GSP (i.e. one that is part of the main, interconnected Transmission System).
A Remote GSP uses the Distribution System to distribute power produced by the
generation to which it is connected without regard to the demand requirements of the
Distribution System (it may be considered a customer of the Distribution System
Operator). Conversely, a conventional GSP supplies power to the Distribution System in
response to its demand, i.e. the Distribution System might be considered the Transmission
System Operator’s customer. If an LLF is not applied to a Remote GSP its effect on
Distribution System losses must be shared in some way between some or all of the other
connectees to the Distribution System, which P270 contends is not appropriate.
The LLF that should be applied to a Remote GSP should be determined by including it in
the Distribution System Operator’s LLF methodology and calculations in the same way as
other elements of the Distribution System. The resultant LLF may be less than 1 (if the
Remote GSP is determined to cause losses on the Distribution System) or greater than 1
(if the Remote GSP is determined to relieve losses on the Distribution System). This would
reflect the arrangements in place prior to the introduction of OFTO arrangements.
Argument against P270
A Line Loss Factor should not be applied to a Remote GSP because LLFs are intended to
adjust energy volumes within a Distribution System in order to apportion losses on the
Distribution System to users of that Distribution System. Whilst it may be argued that a
Remote GSP has an effect on Distribution System losses (in the same way as other
connections to a Distribution System), energy from a ‘conventional’ GSP also physically
affects losses, but it is currently accepted that it is not appropriate to apply an LLF to flows
from a ‘conventional’ GSP. There is no justification to discriminate between ‘conventional’
GSPs and Remote GSPs in the manner proposed by P270.
Application of an LLF to a Remote GSP would result, via the consequent adjustment of the
metered output of that GSP, in an impact on Transmission Losses. This impact would
result in the cost effect (positive or negative) of Distribution System losses associated with
a Remote GSP falling upon, and being shared between, connectees to the national
Transmission System in line with existing BSC rules, which is inappropriate.
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3 Proposed Solution
P270 proposes that the BSC should:
Recognise that physical differences (specifically with regard to losses) exist between
conventional onshore GSPs and types of GSPs that are differently connected to the
Transmission System (i.e. whose connection is remote, such as Offshore Transmission
Connection Points);
Distinguish between GSP types based on the nature of the interconnection between
the GSP and the Transmission System; and
Make provision for the assignment of LLFs to particular types of GSP.
Applicability of P270
The particular issue identified by P270 relates to Offshore Transmission Connection Points,
but the P270 solution would apply on the basis of the nature of the interconnection of the
Transmission System to which the GSP is connected. This is intended to restrict P270 only
to GSPs whose characteristics are considered to justify the use of LLFs.
This approach would allow future network developments to be treated appropriately by
the P270 solution. For instance, if in future an offshore transmission interconnected grid is
developed it would appear inappropriate for the GSPs involved to be treated differently to
onshore GSPs since the offshore grid might act as a flexible energy source/sink in a similar
way to an onshore GSP connected to the interconnected onshore Transmission System.
Retain the pre-OFTO status quo
P270 aims to retain the application of LLFs for Distribution System connections that are
Offshore Transmission Connection Points that existed prior to them becoming Offshore
Transmission Connection Points under the OFTO arrangements. This would reflect the fact
that the change in classification does not change the physical losses arising on a
Distribution System.
Impact of P270
P270 would assign LLFs to meters associated with remotely connected GSPs, such as
Offshore Transmission Connection Points. This would effectively mean that Distribution
System losses attributed to the Offshore Transmission System connection would be taken
into consideration in determining GSP Group Take, and would have a corresponding
opposite effect on calculated Transmission Losses. For example, a 1MW loss allocated to a
Remote GSP’s flow into a Distribution System would reduce GSP Group Take (where inflow
is considered positive) by 1MW and increase Transmission Losses by 1MW. The relevant
loss would be shared among all users of the Transmission System, as with other
Transmission Losses.
Before introduction of the OFTO arrangements, sites affected by P270 may have been
registered in SVA, with their generation affecting GSP Group Take only indirectly. Under
the OFTO arrangements the flow from the offshore network is measured in CVA and
therefore contributes directly to GSP Group Take as an Import to the Distribution System.
Note that P270 aims to assign an LLF to the Offshore Transmission Connection Point, not
to Offshore Generators themselves.
An illustrative example of the application of the P270 solution and an explanation of the
P270 Proposed legal text are set out in Attachment A. Proposed supporting changes to
several BSCPs are also included (Attachments C, D and E).
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4 Impacts & Costs
The changes to the BSC required to implement P270 are set out in Attachment B, and an
explanation of the drafting is included in Attachment A. As well as amendment of Code,
supporting changes would be made to several BSC Procedures (BSCPs 25, 75, and 128) to
reflect the allocation of LLFs to Remote GSPs and ensure processes are documented
clearly and consistently.
ELEXON would also update its procedures and guidance to reflect the P270 solution. We
estimate that changing document and staff training would take 8 Man Days, with an
associated cost of approximately £1920.
No amendment to central systems is needed for P270. The CDCA service provider would
need to update process documentation, but the only practical impact is the application of
the relevant aggregation rules. The service provider has estimated a cost of up to £1000
for the necessary activities but this would be expected to fall under ‘business as usual’.
The only direct impacts of P270 implementation are on LDSOs with connections on their
networks that would be considered Remote GSPs under P270. Such LDSOs would need to
update their LLF methodologies and calculate LLFs for remote GSPs. National Grid and
BSC Parties (as Transmission System users) would be impacted by LLFs being assigned to
Remote GSPs though the consequential effect on Transmission Losses. All activities
arising from these activities would fall under ‘business as usual’, and as such have no
associated cost or lead time for P270 implementation.
5 Implementation
The group considered implementing P270 using an approach where the Code changes
would be made five working days after an Authority decision, with the supporting BSC
changes made in the next suitable BSC Release. The aim of this approach was to limit the
impact of the P270 issue on LDSOs by enabling LLFs to be calculated for Remote GSPs and
applied as soon as possible.
They did not identify any practical problems with this approach, particularly given that only
two LDSOs would be immediately impacted by P270, and the most significantly impacted
site is Robin Rigg, for which an LLF already exists (owing to its operation before the OFTO
arrangements were applied to it). However, the group agreed that in principle all changes
to the BSC and to Code Subsidiary Documents should be made simultaneously wherever
possible.
Since the supporting BSCP changes are relatively minor the group agreed that ELEXON
should draft the changes for inclusion in the P270 Report Phase industry consultation, to
enable their implementation with the P270 Code changes in the event that P270 is
approved.
The group therefore recommends that the Implementation Date of P270 should be ten
working days after a decision is received from the Authority. All Code and BSCP changes
would be made on the Implementation Date.
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6 The Case for Change
Workgroup’s final views against the BSC Objectives
The final majority view of the group was that overall P270 Proposed would not better
facilitate the Applicable BSC Objectives compared with the existing Code baseline. The
majority of the group (five) believed P270 would not improve on the baseline. Two group
members believed P270 would be better overall than the current baseline.
The views of the group are summarised below. Not all members whose views aligned on
the overall effect on a particular Objective necessarily agreed with all the arguments put
forward in relation to it.
Applicable BSC Objectives - pros and cons
Benefits Disadvantages
(a) One member - positive impact:
The Transmission Company has greater
visibility of losses arising in a GSP
Group, potentially promoting efficient
network design because losses can be
taken into account when considering
Distribution System or Transmission-
only connection approach
Majority - neutral impact
(b) Three members - positive impact:
Minor/marginal efficiency benefit due to
increased visibility of losses caused by
non-interconnected Transmission
Three members - neutral impact
One member - negative impact:
Although overall actual losses would be
the same, losses attributed to
Transmission would increase, which in
relation to Transmission System
efficiency is not beneficial
(c) One member - positive impact:
Remove loss allocation distortions,
resulting in appropriate and cost
reflective signals, meaning:
Appropriate losses are used in
calculating LLFs for other sites on a
Distribution System
Losses impact of connection via
Distribution System instead of direct
connection to the Transmission
System (via new transmission lines)
is visible to the Transmission
Company
Majority - negative impact:
Effectively transfers cost of
Distribution System losses to
Transmission users, which penalises
GB Transmission System users
Cost reflectivity might be increased
but singling out some GSPs and not
others is not justified, and the
resultant discrimination ultimately
has a negative effect on competition
Tries to solve a Distribution losses
incentive problem under BSC
Two members - neutral impact
(d) One member - positive impact:
Promotes efficiency and clarity in the
administration of audit and approval of
LLFs under the BSC
Majority - neutral impact
One member - negative impact:
Increases complexity of BSC by treating
types of GSP differently
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7 Panel Discussions
Panel’s consideration of Assessment Report
The Distribution System Operator Representative views do not count in the overall views
of the Panel against the Applicable BSC Objectives. However, the Representative believed
P270 would facilitate Objective (c) because it would be more appropriate for the impact of
Remote GSPs on Distribution System losses to be spread across Transmission System
users instead of being attributed to some or all users of the relevant Distribution System.
They also believed that P270 would have a minor benefit against Objective (d).
A Panel member felt that the comment in the P270 Detailed Assessment that ‘It was
perceived that approval of P242 would have nullified a policy intent explicitly stated by
Ofgem/BERR’ (Attachment A, subsection ‘ELEXON analysis’) might give a misleading
impression of the motives of the Proposer of P242 in raising that Modification.
A Panel member suggested that the underlying issue is defining whether particular losses
are considered as Transmission or Distribution related, which is not a BSC issue. This
member could see arguments both in favour and against P270, but ultimately felt that the
issue it seeks to address is not a BSC issue. The member noted that Robin Rigg, the
specific site that was the driver for raising P270, was built under a different regime (i.e.
prior to the OFTO arrangements).
Another Panel member agreed, and believed that Robin Rigg would remain an anomaly
since it is unlikely that significant further Distribution System-connected Offshore
Transmission will be developed because the OFTO arrangements.
A Panel member questioned whether P270 could be said to improve the cost reflectivity of
losses allocation given that it would result in losses being spread across all Transmission
users, not attributed to a particular participant. Another member suggested this could be
considered justifiable given that the Distribution System losses impact that would be
spread amongst Transmission System users would arise from the operation of a
Transmission System connection.
A Panel member believed that the issues relating to P270 were an area for LSDOs to
pursue with Ofgem, and not a matter to be resolved under the BSC.
Panel’s initial views
The unanimous initial view of the Panel was that P270 Proposed would not better facilitate
the Applicable BSC Objectives overall compared with the current baseline.
All Panel members supported the views of the majority of the P270 Modification Group, as
set out in section 6, above. Based on these views and the considerations detailed above
the Panel unanimously believed that P270 Proposed would not better facilitate the
Applicable BSC Objectives overall and that (compared with the existing baseline) the P270
Proposed solution would:
Have a neutral impact on Applicable BSC Objective (a);
Have a neutral impact on Applicable BSC Objective (b);
Not better facilitate Applicable BSC Objective (c); and
Have a neutral impact on Applicable BSC Objective (d).
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8 Consultation Responses
Summary
The full responses to the P270 Report Phase Consultation are available on the P270 page
of the ELEXON website. We received seven responses, as summarised in the table below.
A slim majority of four respondents agreed with the Panel’s initial view that P270 should
be rejected. Three respondents believed P270 should be approved.
Summary of P266 Report Phase Consultation responses
Question Response
1. Do you agree with the Panel’s initial view that the Proposed
Modification should be rejected?
Yes: 4
No: 3
2. Do you agree that the legal text delivers the intention of P270? Yes: 7 No: 0
3. Do you agree with the proposed redlined changes to BSCPs 25, 75 and
128?
Yes: 5
No: 0
Other: 2
4. Do you agree with the Panel’s suggested Implementation Date? Yes: 7
No: 0
Agree with rejection
Four respondents that believe P270 should be rejected agreed with the arguments put
forward by the majority of the P270 Workgroup and supported by the Panel. Three of the
four agreed P270 would have a negative impact with respect to Applicable BSC Objective
(c) and a neutral impact on Objectives (a), (b) and (d).
One respondent, EDF Energy, also believed that P270 would have a negative impact in
relation to Objectives (b) and (d). EDF Energy note that including some Distribution
System losses in the System Operator incentive to reduce Transmission Losses would raise
complex issues about the interaction between Transmission and Distribution System
operation, which they believe are beyond the scope of P270, and do not believe P270
would better facilitate Objective (b). They also believe P270 would have a negative impact
with respect to Objective (d) by adding complexity to the BSC arrangements.
Disagree with rejection
All three of the respondents that disagreed with the Panel’s initial recommendation, and
supported P270, operate as LDSOs. The response from UK Power Networks suggested
that approval of P270 would resolve a conflict caused by the introduction of the OFTO
arrangements.
The P270 Proposer, Electricity North West Limited (ENW), confirmed that its views remain
the same as when it raised P270, i.e. that P270 would have a positive impact with respect
to Applicable BSC Objectives (a) and (c), and argued against the case for rejecting P270.
ENW believed that two of the main arguments against P270 relate to Objective (c) (that
P270 would transfer the impact of some Distribution System losses into Transmission
Losses, penalising Transmission System users, and that it would not improve cost
reflectivity because losses would be spread across Transmission System users, not
attribute them to a particular participant) ignore that under the OFTO arrangements the
Transmission Company itself is a Distribution System user (they are DCUSA signatories and
liable for DUOS charges).
ENW believe it is appropriate that the Transmission Company should be allocated
Distribution System losses caused by such connections, and argue that this would allow
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consistent application of Objective (c) to all Distribution System users. ENW suggest that
how the cost impact is then allocated to Transmission System users, is a separate matter
and beyond the scope of P270. This view was shared by Western Power Distribution in its
response.
ENW also argue that the materiality of the losses transferred from Distribution to
Transmission under P270 is small compared with overall Transmission Losses, but without
P270 the potential distortion of losses signals could be significant for individual Distribution
Systems users. They believe this should be considered in relation to Objective (c).
Finally, ENW commented that it is hard to understand the view that the P270 issues are
not a matter for resolution under the BSC, and that therefore LDSOs should pursue such
issues with Ofgem, given that matters such as LDSOs’ LLF calculation methodologies are
within the scope of the BSC, and that arguments relating to P270 are relevant to
Applicable BSC Objective (c). ENW felt it would be useful to understand Ofgem’s view on
this.
Legal Text and BSCP Changes
Respondents unanimously agreed the legal text to implement P270 in the BSC. All
respondents that expressed a view on the BSCP changes drafted to support
implementation of P270 supported the proposed drafting. Two respondents declined to
give a view on the BSCP changes.
Implementation
Respondents unanimously supported the proposed P270 Implementation Date and
approach.
Further comments
Three respondents had comments further to their answers to the P270 consultation
questions. In support of P270, Western Power Distribution suggested it would facilitate
calculation of more accurate LLFs by LDSOs, which would improve Settlement accuracy.
ScottishPower’s response noted that in their opinion there is no real defect within the BSC.
They believe that the principles currently set out in the BSC allow for the correct allocation
of losses in a cost-reflective and appropriate way, and the issue experienced by the P270
Proposer is due to problems with the application of their Distribution LLF methodology and
the losses incentives provided through Ofgem. ScottishPower suggest the incentives
should be updated to take into account the OFTO arrangements. Which respect to the
particular case that occasioned P270, ENW’s LLF methodology should allow recalculation of
the requisite LLFs to compensate for the impact of Robin Rigg. ScottishPower felt these
problems are outside the scope of the BSC.
EDF Energy suggested that there might be instances where GSPs not intended to be
Remote GSPs unintentionally fall into the category of ‘Remote GSP’, though they had not
positively identified any. They noted P270 would create interaction between incentives on
the Transmission Company and those applied to affected LDSOs, though they did not think
this interaction would materially affect actual flows, losses or investment on the relevant
networks. EDF Energy also noted that as well as the main impact of P270 on LDSOs, and
consequent impact on the Transmission Company and Transmission System users, P270
would also impact users of an affected Distribution System via small changes to generic
LLFs (and hence GSP Group Correction) and potential changes in site-specific LLFs.
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9 Recommendations
Having considered the P270 Draft Modification Report, we invite the Panel to:
NOTE the P270 draft Modification Report and the consultation responses;
CONFIRM the recommendation to the Authority contained in the P270 Draft
Modification Report that Proposed Modification P270 should not be made;
APPROVE an Implementation Date for Proposed Modification P270 of ten working days
after an Authority decision is received;
APPROVE the legal text for Proposed Modification P270;
APPROVE the P270 Modification Report or INSTRUCT the Modification Secretary to
make such changes to the report as may be specified by the Panel.
10 Further Information
More information is available in:
Attachment A: Detailed Assessment
Attachment B: Legal Text Proposed
Attachment C: BSCP25 Redlined Changes
Attachment D: BSCP75 Redlined Changes
Attachment E: BSCP128 Redlined Changes
All consultation and impact assessment responses received, the P270 Assessment Report
and other P270 documentation are available from the P270 page of the ELEXON website.
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What stage is
this document in the process?
Stage 03: Attachment A: Detailed Assessment for P270
P270: The Application of Line Loss Factors to GSPs that are not Transmission-interconnected
Contents
1 Background 2
2 Terms of Reference 5
3 Illustrative example of P270 solution 6
4 P270 Legal Text 10
5 Initial Workgroup Discussions 13
6 Analysis of the Materiality of P270 17
7 Final Workgroup Discussions 19
8 Costs and Impacts 24
9 Workgroup Membership 25
10 Glossary 25
About this document:
This is Attachment A to the P270 Assessment Report. This attachment provides additional
detail, including details of the Workgroup‟s discussions.
Any questions?
Contact: Dean Riddell
dean.riddell@ elexon.co.uk
020 7380 4366
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1 Background
Line Loss Factors
A Line Loss Factor (LLF) is an adjustment factor applied to readings from a Metering
System to adjust for electrical losses occurring on a Distribution System. At present an
LLF may only be applied to Metering System at a Boundary Point. The aim is to calculate
an associated amount of energy at the Transmission System Boundary for use in
Settlement. LLFs are covered by Section K of the BSC and BSC Procedure (BSCP) 128
„Production, Submission, Audit and Approval of Line Loss Factors‟.
Licensed Distribution System Operators (LDSOs) calculate LLFs and submit them to
ELEXON annually. LDSOs must calculate the LLFs in accordance with an LLF methodology
that complies with the principles set out in BSCP128.
Grid Supply Points
Grid Supply Points (GSPs) are also covered in Section K. Section X of the BSC defines a
GSP as „a Systems Connection Point at which the Transmission System is connected to a
Distribution System and includes an Offshore Transmission Connection Point‟. Each GSP is
the responsibility of a Distribution System Operator, who must ensure Metering Equipment
is in place and registered, except that the Transmission Company (National Grid) is
responsible (as NETSO) for all Offshore Transmission Connection Points.
A GSP is a Systems Connection Point, not a Boundary Point between the Total System (of
Transmission and Distribution) and an end user. As such, an LLF may not currently be
applied to a Metering System at a GSP.
Offshore Transmission Connection Points
Under the Offshore Transmission Owner (OFTO) arrangements, offshore networks at
132kV or higher became part of the Transmission System (or, in the case of existing
networks, will become Transmission System when so designated). Where such a network
connects to an onshore Distribution System, the connection is known as an Offshore
Transmission Connection Point. Offshore Transmission Connection Points are a type of
GSP, and as such cannot presently be assigned an LLF.
Prior to the OFTO arrangements, an LLF calculated by the Distribution System Operator
would be applied to a connection between an offshore generator and an onshore
Distribution System. Under the OFTO arrangements, metering at the Offshore
Transmission Connection Point is CVA registered by the Transmission Company and no LLF
is applied.
What is the Issue?
P270 contends that differences between different types of GSPs exist due to the OFTO
arrangements, and the BSC arrangements do not recognise these differences. The
Proposer believes that this results in some types of GSP being treated in a manner that
does not reflect their physical characteristics.
In particular, P270 focuses on the assignment of LLFs, and argues that the characteristics
and situation (geographically and in network terms) of some GSPs, such as Offshore
Transmission Connection Points, means that it would be appropriate to apply LLFs to
them.
In the case of Offshore Transmission Connection Points this would amount to maintaining
the pre-OFTO status quo by continuing to apply LLFs to them. The effect on LLFs
Offshore Transmission Connection Point
A GSP that connects an Offshore Transmission System to an (onshore) Distribution System.
Grid Supply Point
A point where the Transmission System (including an Offshore Transmission System) is connected to a Distribution System.
Line Loss Factor
A multiplier applied to data from a Metering System connected to a
Boundary Point of a
Distribution System to convert it to an equivalent
value for the Transmission
System Boundary.
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assigned to other Metering Systems in the Distribution System is also relevant, since the
effect of the now-Offshore Transmission Connection Points on Distribution System losses
would previously have been taken into account in calculating LLFs for other Metering
Systems.
Interconnected Transmission System and remote connections
The Proposer argues that there is a fundamental difference between the (onshore)
interconnected Transmission System and a remotely connected part of the Transmission
System (i.e. not interconnected directly with other parts of the Transmission System). An
Offshore Transmission System connected to a Distribution System is an example of the
latter, and are used here to illustrate this difference.
P270 contends that a conventional onshore GSP has no LLF because it effectively acts as
an infinite energy source/sink to the Distribution System Operator, i.e. required energy
flows at the boundary (the GSP) are achieved by the addition or reduction of despatched
generation from the interconnected Transmission System. In other words, the
Transmission System does not carry out activities that by their nature increase or decrease
losses on the Distribution System; it responds to the Distribution System‟s energy
requirements.
However, an Offshore GSP (an Offshore Transmission Connection Point) could be
considered to join an offshore Transmission System to the main Transmission System via a
Distribution System. P270 argues that such an Offshore GSP effectively drives energy
across a Distribution System in one direction only, either causing or reducing losses on the
Distribution System (depending on the interaction with the other Distribution System
elements).
The Proposer believes that from the perspective of the Distribution System Operator, the
behaviour of such an Offshore GSP is more akin to that of a Distribution System user,
whose Metering System would receive an LLF representing an increase or reduction in
Distribution System losses, than a „normal‟ GSP connected to the interconnected
Transmission System. P270 contends that LLFs should also therefore be applied to
Offshore GSPs, and similarly remote connection points to the Transmission System (which
would be collectively classed as Remote GSPs under P270).
Impact of the issue
The Proposer believes that it is appropriate in principle to apply LLFs to some GSPs, as
discussed above. In terms of material impact, P270 contends that the identified issue
unjustifiably distorts LLFs applied on an affected Distribution System.
General Effect
The P270 issue might have a significant effect on sites where site-specific LLFs are
calculated on an interactive basis (see below). It has a less pronounced effect on other
sites connected to the Distribution System which are allocated generic LLFs, as they share
expected residual losses according to the LLF methodology.
If the connection of a site previously assigned an LLF becomes an Offshore Transmission
Connection Point the Distribution System losses are the same as before application of the
OFTO arrangements, but losses previously covered by the site‟s LLF are smeared across
other sites in the Distribution System. This could affect Generic and Site Specific LLFs
within the GSP Group and/or impact the Group Correction Factor.
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Under P270, loss adjustments corresponding to losses previously associated with an
offshore generator that was (or would have been) connected directly to a Distribution
System prior to the OFTO arrangements would be allocated to Transmission Losses and
shared by all Transmission users. Under the baseline, without P270, such losses would be
shared between some or all other users of the relevant Distribution System by either
impacting the applicable LLFs or via GSP Group Correction for NHH sites.
Interactively Determined LLFs
If multiple Extra High Voltage sites (requiring site-specific LLFs) are connected such that
their LLFs are calculated on an interactive basis then the identified issue can have a
pronounced and local impact. Prior to the OFTO arrangements all the sites involved in
such a situation would be assigned Site Specific LLFs, calculated to share the losses
between the sites as determined by the Distribution System Operator.
If one or more of the sites in such a situation is affected by the OFTO arrangements the
LLFs of any sites that remain outside the OFTO arrangements may be affected, although
neither the physical network, the characteristics of the sites nor the physical losses arising
on the Distribution System are changed. The Proposer believes that this is inappropriate,
and also considers that the principle of the issue remains the same whether the LLFs
involved are greater than or less than one, though this has a bearing on the practical
effect.
Losses Incentive
The Proposer suggests that the impact on LLFs as a result of an LLF not being applied to
an Offshore Transmission Connection Point could potentially have a direct financial impact
on the Distribution System Operator under the Losses Incentive (Charge Restriction
Condition 7 of the DNO Licence). This is outside the scope of P270, but was noted by the
group.
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2 Terms of Reference
P270 Terms of Reference
The P270 Workgroup comprised members of the Settlement Standing Modification Group. The group considered the following areas:
Ref Area Page ref
1 Development of the P270 Proposed solution 6
2 Any alternative solutions n/a
3 Implementation approach Main report
4 Assessment against the Applicable BSC Objectives Main report
5 Materiality of the issue identified by P270 15
6 Quantification of P270 costs and benefits 15, 22
7 Environmental effects of P270 n/a
8 Impact on industry participants 22
9 Consistency with wider industry arrangements 12
10 Impact on Transmission Losses 13
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3 Illustrative example of P270 solution
In order to illustrate the effect of the P270 solution and how it would work at a high level,
this section sets out an example of a simple arrangement of an offshore generator
connected to a Distribution System, and compares the outcomes under different
circumstances. The example is considered under:
The situation prior to introduction of the OFTO arrangements;
The current baseline arrangements; and
The P270 arrangements.
Note that this is a simplified example and the volumes of energy and other quantities are
not intended to be realistic or representative of the actual materiality of the issue. The
example shows the situation with an LLF of less than one applied, whereas application of
LLFs greater than one is possible and would affect the practical implications for the
relevant participants.
This example is therefore intended only to demonstrate the effect that the assignment, or
not, of LLFs to GSPs whose connection to the Transmission is relatively remote (e.g. an
Offshore Transmission Connection Point) can have on overall Transmission Losses, GSP
Group take and other sites‟ LLFs.
Pre-OFTO Arrangements
Prior to the introduction of the OFTO arrangements, the offshore/onshore connection in
the example was the responsibility of the offshore generator, and the Settlement Metering
was located onshore. For Settlement purposes, the generators output was its net output
(output at the offshore platform minus losses over the offshore/onshore connection)
multiplied by the LLF determined by the Distribution System Operator. In this example the
LLF is less than one, meaning the generator is considered to cause losses on the
Distribution System, so its output is scaled down to take this into account.
In physical energy terms, the Distribution System receives 1100 MWh, made up of 1000
MWh from the Transmission system via a normal onshore GSP and 100 MWh from the
offshore generator. However, the generator‟s energy is subject to its assigned LLF, in this
case 0.99. In this example the generator is registered in CVA, therefore the GSP Group
take is 1099 MWh (if it is SVA registered the GSP Group take would be 1000 MWh).
Transmission System
Distribution
System
Offshore meter
(not Settlement Meter)
reading: 105MWh
Onshore meter (Settlement Meter)
reading: 100MWh
(LLF = 0.99)
Onshore meter
reading: 1000MWh
Offshore
Generator
ONSHORE
OFFSHORE
Onshore/Offshore Boundary
GSP (onshore)
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Distribution System losses considered to be associated with the offshore generator are
allocated to the generator itself via assignment of an LLF to it. There is no impact on
Transmission Losses.
Current Arrangements
The current baseline includes the OFTO arrangements (though they are not yet applied in
all relevant situations) which means that the connection between the offshore generator
and the onshore Distribution System is part of the Offshore Transmission System and as
such is the responsibility of National Grid (as NETSO). The point where the Offshore
Transmission System connects to the Distribution System is an Offshore Transmission
Connection Point, which is a GSP and therefore not given an LLF.
The Settlement Meter for the offshore generator is located at the offshore platform (unless
a dispensation is in place enabling it to be located elsewhere) and the generator‟s full
output at that point is assigned to it for the purposes of Settlement.
The energy lost between the offshore generator and the onshore meter at the Offshore
Transmission Connection Point contributes to the national total Transmission Losses (as
with losses on any other part of the Transmission System). The onshore reading at the
Offshore Transmission Connection Point is not adjusted by the application of an LLF.
Physically, the Distribution System still receives 1100 MWh, made up of 1000 MWh from
the Transmission system via a normal onshore GSP and 100 MWh from the Offshore
Transmission Connection Point. Neither is subject to loss adjustment by an LLF, but the
Offshore Transmission Connection Point is registered in CVA, so the GSP Group take is
1100 MWh.
The offshore generator is no longer subject to Distribution System loss adjustment via LLF
assignment. Any Distribution System loss that would previously have been considered to
be associated with the generator‟s output is allocated between other Distribution System
users; there is no impact on national Transmission Losses.
Transmission System
Distribution
System
Offshore meter
(Settlement Meter)
reading: 105MWh
Onshore meter
reading: 100MWh
Onshore meter
reading: 1000MWh
Offshore
Generator
ONSHORE
OFFSHORE
Onshore/Offshore Boundary
GSP (onshore)
Offshore Transmission
Connection Point
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P270 Solution
Under P270 an LLF would be assigned to the Offshore Transmission Connection Point.
Since it is based on the same network characteristic and losses it would be the same as
that applied to the offshore generator‟s delivered volumes under the pre-OFTO
arrangements, i.e. 0.99.
P270 would include in the total Transmission Losses the increase (in this example) of
Distribution Losses caused by the energy flowing onto the Distribution System from the
OFTO network. Because the energy metered onshore is adjusted down by the LLF of 0.99
the calculated Transmission Losses across the onshore/offshore connection is increased
compared with that under the baseline (from 105 – 100 = 5MWh to 105 – 99 = 6MWh).
The status of the offshore generator is not affected at all (other than through its share of
the effect on Transmission Losses). Its metered volume remains the same as under the
current baseline, and it would not be allocated any distribution losses. Its treatment
remains equivalent to that of other directly connected generators.
The only effect which would in any way impact the generator is that (like all BM Units)
their TLM values would change slightly due to the very small difference in the national
total of Transmission Losses (in this example the additional 1MWh).
Transmission System
Distribution
System
Offshore meter
(Settlement Meter)
reading: 105MWh
Onshore meter
reading: 1000MWh
Offshore
Generator
ONSHORE
OFFSHORE
Onshore/Offshore Boundary
GSP (onshore)
Offshore Transmission
Connection Point
Onshore meter reading:
100MWh (LLF = 0.99)
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Comparison
The effects described above are tabulated below. It can be seen that across the three
scenarios the energy physically delivered to the Distribution System does not change.
Example parameters under various arrangements
Pre-OFTO Baseline1 P270
Import from main, onshore
Transmission System 1000 MWh 1000 MWh 1000 MWh
Import from offshore generator 100 MWh 100 MWh 100 MWh
Total energy delivered to
Distribution System 1100 MWh 1100 MWh 1100 MWh
LLF applied to offshore/onshore
connection 0.99
None
(i.e. 1.00) 0.99
OFTO system contribution to
Transmission Losses Zero 5 MWh 6 MWh
Generator‟s Settlement Metered
Volume 99 MWh 105 MWh 105 MWh
GSP Group Take 1099 MWh2 1100 MWh 1099 MWh
Under the baseline (i.e. with the OFTO arrangements) the generator is not directly
responsible for losses over the offshore circuits between the generator and Distribution
System because this connection is now Transmission System and as such these losses are
now considered Transmission Losses. The generator‟s metered volume for Settlement
does not therefore include the losses on the connection, and increases accordingly.
However, it is also apparent that the introduction of the OFTO arrangements into the
baseline affects the GSP Group Take. In this example this would have a diluted effect on
all sites in the Distribution System, but in different circumstances could also have an
impact on a few particular sites, via their assigned LLFs. If other users‟ LLFs do not
change the impact would affect the GSP Group Take, but if LLFs of other users change
GSP Group Take may be unaffected.
Under the P270 Proposed solution the offshore generator‟s metered volume remains the
same as under the baseline but the GSP Group Take is restored to its previous value by
the application of an LLF to the onshore/offshore connection. The contribution of the
OFTO system to Transmission Losses is conversely affected, in this example increasing.
The Proposer believes that these effects are justified by the characteristics of the network
arrangements and reflect a cost reflective allocation of energy volumes to the participants
involved.
1 Baseline is post-OFTO and pre-P270. 2 Assuming (for the purposes of this example) that the Generator is CVA-registered.
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4 P270 Legal Text
P270 concerns the application of LLFs to particular types of GSP, and does not directly
affect the application of LLFs relating to Boundary Points. The two main aspects of the
P270 solution are:
Introduce a distinction between GSP types based on how they are connected to the
Transmission System; and
Enable LLFs to be assigned to appropriate GSP types.
Changes to BSC Sections K and X are proposed to support this approach. The changes are
detailed in Attachment A. This section explains the intent of the changes and how they
are intended to deliver the P270 Proposed Solution.
The group considered using the term „Interconnected‟ in the text (e.g. Interconnected
Transmission System, etc) but felt that this might be potentially confusing given the
provisions in the BSC relating to Interconnectors and the use of the term „Main
Interconnected Transmission System‟ (MITS) in the Transmission Charging Methodology
(which has a similar intent, but is not equivalent to, the P270 term). The group therefore
agreed to use the term „contiguous‟ to describe a network being interconnected in the
sense intended by P270 on the basis that they believed this would be clearer.
Section K, Classification and Registration of Metering Systems and
BM Units
Amend K1.7.3 so it is clear that LLFs associated with Remote Grid Supply Point are not
intended to be excluded from this provision by the P270 solution. Also add words to
reflect the definitions added by P270.
Section X, Definitions and Interpretation
Annex X-1, General Glossary
Add definitions of:
1. Contiguous Transmission System: to specify a subset of the overall
Transmission System which is the „main‟ Transmission System by reference to the
number of GSP Groups to which a network is connected by unbroken Transmission
Assets. The intent is that isolated parts of the Transmission System which are
subject to the P270 provisions are not captured by this definition;
2. Contiguous Transmission System Boundary: to define where a boundary is
part of the „main‟ system by building on the first new definition, above. The
wording reflects the existing Transmission System Boundary definition (which
remains in the BSC); and
3. Remote Grid Supply Point: this is the type of GSP that will fall under the P270
provisions, i.e. will be able to have a LLF applied to it.
Annex X-2, Technical Glossary
Amend the definition of CVA Line Loss Factor to extend it to cover Remote Grid Supply
Points. The new provision applying to Remote Grid Supply Points will reflect the wording
for the existing provision relating to Boundary Points on a Distribution System, which is not
impacted by P270.
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What constitutes Contiguous Transmission System?
This section explains what constitutes Contiguous Transmission System under P270 (and
what does not). In the examples in this section all the connections are such that they are
designated as Transmission System. Some elements of the examples are hypothetical
network elements (i.e. of which no examples currently exist) and are included for
illustrative purposes; where this is the case it is clearly stated.
Contiguous Transmission System
The criterion for Transmission System to be considered Contiguous Transmission System
under P270 is that it is connected to more than one GSP Group by unbroken Transmission
Assets. P270 does not seek to define the main onshore Transmission System as the sole
Contiguous Transmission System, but instead leave open the possibility that other
networks may be considered Contiguous Transmission System if they meet the relevant
criteria.
The diagram above shows part of the main, onshore Transmission System. Because it is
connected to both of the GSP Groups shown (as well as all the other GSP Groups) it is
considered Contiguous Transmission System under P270.
The diagram above also shows an Offshore Transmission network comprising Offshore
Generator A which is connected to both GSP Group A and GSP Group B. Under P270 this
would also be considered Contiguous Transmission System under P270. Note however
that no instances of this arrangement currently exist.
Not Contiguous Transmission System
Any Transmission System not connected to multiple GSP Groups is not Contiguous
Transmission System under P270.
The diagram below shows an Offshore Transmission network comprising Offshore
Generator B which is connected to GSP Group B. Since it is connected to only one GSP
Group it does not constitute Contiguous Transmission System under P270.
The diagram below also shows a hypothetical arrangement where a generator located
onshore is connected to a GSP Group via a network that is designated as Transmission
System, i.e. the generator is not a conventionally embedded generator and is not
Tra
nsm
issio
n S
yste
m
GSP Group B
ONSHORE OFFSHORE
Onshore/Offshore
Boundary
GSP Group A Offshore
Generator A
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connected directly to the main Transmission System. Because it is connected to only one
GSP Group it also would not be considered Contiguous Transmission System under P270.
As stated, this is a hypothetical arrangement; no instances of this set-up currently exist,
and it is difficult to envisage circumstances in which this or a similar arrangement could
arise. However, this configuration is included to illustrate that P270 does not seek to
differentiate between Transmission System networks on the basis that they are offshore; if
a Transmission System network located onshore meets the criteria that identify it as not
Transmission System interconnected under P270 it would not be considered Contiguous
Transmission System.
Summary
The P270 solution, and hence legal text, attempts to differentiate between Transmission
System networks, and their GSPs, based on whether or not they exhibit Transmission
System interconnection. The legal text does this by considering that an interconnected
network will be connected to multiple GSP Groups.
As explained above, the P270 legal text is not drafted to specifically distinguish either:
The main, onshore Transmission System from other Transmission System networks; or
Offshore Transmission System networks from other Transmission System.
Tra
nsm
issio
n S
yste
m
GSP Group B Offshore
Generator B
ONSHORE OFFSHORE
Onshore/Offshore
Boundary
GSP Group A
Onshore
Generator
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5 Initial Workgroup Discussions
The group believed that the key question underlying P270 is whether it is justifiable, in the
particular circumstances identified by P270, to effectively shift the cost of losses occurring
on a Distribution System into the overall Transmission Losses allocated on a uniform basis
between all generation and demand users of the Transmission System.
The Proposer believed that the P270 approach would be appropriate because it would
make the losses consequences of transmission connection and operation decisions visible
to the Transmission Company. The Proposer believed the equality of treatment of onshore
and offshore Transmission connected generation would be maintained under P270.
The view of some group members was that the P270 approach was not appropriate. A
member noted that there are currently no circumstances where Transmission Losses
include Distribution losses, and commented that whereas prior to the OFTO arrangements
the embedded BM Unit received an LLF and picked up the cost of Distribution System
losses, under P270 the cost would be socialised via the Transmission Losses
arrangements.
The group did not believe that any actual change to Distribution or Transmission System
flows or losses would occur if P270 was approved (though they may be „reclassified‟). A
majority felt that future Transmission or Distribution System investment decisions would
not be affected by approval of P270.
A member that did not support P270 suggested that it would be discriminatory to identify
a particular part of the Transmission System and apply an LLF to it. This member believed
that the P270 issues could be handled under the LLF methodologies without change to the
BSC.
The Proposer argued that accommodating Distribution Losses associated with embedded
transmission would inevitably result in distortion of the losses costs for other connectees
to the Distribution System, whether by affecting the site specific LLFs of a limited number
of users or by socialising across all Distribution System users.
A member considered this issue part of a wider issue of flows between GSPs, both from
and to Transmission across Distribution Systems (as in this case) and from and to
Distribution Systems across Transmission, due to embedded generation. Output of
embedded generators could significantly affect flows from individual GSPs on a Distribution
System, affecting Distribution (and Transmission) losses in a manner that could be
significant and difficult to predict.
This member did not believe it was obvious that the type of GSP identified by the P270
solution was different to other GSPs; some, most or all of the flow entering a Distribution
System might be used within that Distribution System, even if an Offshore Transmission
System is isolated from the rest of the transmission system. The member felt this
situation would not be significantly different from that of conventional GSPs, and therefore
to focus on the particular situation identified by P270 could be viewed as discriminatory.
Some of the group felt that, in practice, it was unlikely that P270 would have any effect on
future connection decisions for offshore networks. Since embedded benefits are not
applicable to embedded transmission connections it is unlikely that new offshore networks
will consider connection via Distribution System.
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A member noted that while they were by no means satisfied with the OFTO arrangements
overall they were also keen not to introduce small exceptions/discriminations into the
arrangements.
Consideration of P270 and P242
Though not directly related to P270, rejected Modification P242, „Treatment of Exemptable
Generation Connected to Embedded Offshore Transmission Networks,‟ proposed changes
to preserve the status quo for some participants impacted by the Offshore Transmission
Arrangements.
P242 sought to allow Offshore Exemptable Generators that connect onshore to a
Distribution System the option of being treated in the same way as onshore Exemptable
Embedded Generators. Under the Offshore Transmission Arrangements such generators
must be treated the same as directly-connected Generators.
The Authority rejected P242 because it considered that it would be inappropriate to
introduce different treatment within the category of transmission connected generation,
that seeking to amend the arrangements would arguably decrease regulatory certainty and
hinder effective competition, and that P242 would not promote cost reflective charging
and in any case the issues identified do not fall under the BSC.
There are similarities in the areas relevant to P242 and P270 (i.e. both were raised in
response to changes resulting from introduction of the offshore regime and both aim to
retain the status quo in particular areas in some circumstances). The group considered
the issues identified by the P242 decision to try to give a view on whether they have any
relevance to P270. Further information on P242 can be found on the P242 webpage on
the ELEXON website.
ELEXON analysis
To try to understand and compare how P242 and P270 relate to the intent of offshore
transmission policy ELEXON reviewed the work of the Offshore Transmission Embedded
Transmission Working Group (OTETWG). The OTETWG met three times in January 2008,
and produced a report (which can be found on Ofgem's website).
Section 4 of the report appears to recognise that the Generator should be treated as
directly connected, not embedded. Paragraph 4.1 states that „The power station would be
transmission connected but the transmission connection would be connected via a
distribution system‟.
Section 5 appears to conclude that the LDSO should treat an OFTO connection in the same
way as other users of the Distribution System. Paragraph 5.7.5 reads:
OTETWG noted that under the DCUSA, users of the distribution system are
responsible for installing settlement metering. OTETWG recommends that
current BSC and/or DCUSA arrangements should be developed to ensure that a
distribution licensee is able to treat offshore transmission connections consistently
to other types of customer connections to the distribution system.
The OTETWG conclusions were reflected the June 2008 Ofgem/BERR Regulatory Policy
Update (available from Ofgem's website). This Update included explicit discussion of
transitional arrangements for existing schemes, and stated that it was not appropriate to
give them TNUoS benefits. ELEXON‟s interpretation is that:
It was perceived that approval of P242 would have nullified a policy intent explicitly
stated by Ofgem/BERR; but
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The P270 solution appears to be consistent with the OTETWG views and therefore
Ofgem/BERR policy intent.
Group discussions
The views of the group were split on the nature of the relationship, if any, between P242
and P270.
The Proposer believed that P270 should be assessed on its merits against the Applicable
BSC Objectives, but that the P270 solution does not conflict with any of the reasons given
for the rejection of P242. P270 is specifically aimed at the connectee to the Distribution
System, i.e. the NETSO, and is not attempting to change the arrangements between the
NETSO and the Offshore Generator.
Furthermore, the Proposer noted that P270 specifically seeks to identify all Transmission/
Distribution connection points whose characteristics meet the P270 criteria, and not
restrict the P270 provisions to Offshore Transmission Connection Points. The intention is
to link the P270 solution to the physical characteristics that drive the need for an LLF, i.e.
not designate the issues identified by P270 as solely relating to the OFTO arrangements.
One member did not believe P242 had any relevance to the assessment of P270, noting
that the assessment of Modifications under the BSC should be based on whether or not
the Applicable BSC Objectives would be better facilitated by the proposed change.
Further to this overall view that considerations relating to P242 were irrelevant and
inappropriate for assessment of P270, the member also disagreed with ELEXON‟s analysis
in a number of areas. In relation to the OTETWG‟s views, they felt that the OFTO
arrangements contain inconsistencies because they were also a product of Use of System
Charging Methodology Modification Proposal GBECM-08, „Introduction of charging
arrangements associated with Offshore Transmission Networks‟. The member also felt
that approval of P270 would contradict the rejection of P242 by designating the Offshore
Transmission Network connecting the generator to the Distribution System as not part of
the „main‟ Transmission System
Another member disagreed with ELEXON‟s analysis because they believed that, although it
appears that it is intended that „embedded transmission‟ be subject to DUoS charges in the
same manner as any other Distribution System user, this does not explicitly apply to LLFs.
This was based on feedback from Ofgem in relation to another BSC change (CP1343) that
„Our understanding is that change proposal 1343 regarding line loss factors for customers
metered at primary substations does not interact with the calculation and billing of use of
system charges to HVS customers. If that is the case we have no reservations with the
proposals at this point in time‟, which the member interpreted to mean there is no
association between DUoS charges under the DCUSA and LLF allocation under the BSC.
The rest of the group considered ELEXON‟s analysis and did not have any strong views on
the matter. Overall, the group did not identify any issues relating to P242 that they felt
would affect their assessment of P270 against the Applicable BSC Objectives or that they
believed should be brought particularly to the attention of the Authority.
Potential interaction between P270 and P229
The group noted that P270 would effectively shift the cost (or saving) resulting from the
effect of a Remote GSP on the losses on a Distribution System from others users of the
Distribution System to the Transmission Loss costs of Transmission System users. P229,
„Introduction of a seasonal Zonal Transmission Losses scheme‟, which is currently awaiting
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an Authority decision, would change how Transmission Losses are allocated from a
uniform national approach to zonal allocation.
While acknowledging that P270 must be assessed against the existing Code baseline, the
group therefore believed it would be prudent to consider how P229 and P270 would
interact if both were approved. Under P229 there are two separate mechanisms for
apportioning transmission losses:
A locational mechanism (implemented using TLFs)
Each BM Unit is given a TLF, which is calculated using a Load Flow Model of Nodes on
the Transmission System and reflects variable losses on the Transmission System.
The TLF values do not reflect any losses on the distribution system caused by OFTO
networks (page 8 of the P229 Modification Report: “Because losses over Distribution
Systems are not Transmission Losses they would be excluded from TLF calculation”).
A non-locational mechanism (using TLMOs as currently)
This mechanism allocates all the Transmission Losses that aren‟t included in the TLF
value, socialising them across users, while maintaining the current 45/55 overall split
between generation and demand.
If both P229 and P270 are implemented losses on a Distribution System resulting from an
OFTO connection would not be reflected in the TLF calculation, but would be smeared
across all users via the TLMO, just as they would be under P270 without P229. The group
therefore agreed that P229 does not have any significant interaction with P270.
LLF definition and LLF Methodologies
In developing the P270 solution the group noted that the BSC definition of an LLF is that it
converts data into an equivalent value at the Transmission System Boundary. However,
the group questioned whether this relatively straightforward description was fully reflective
of the determination of LLFs, which it noted is complex and must accommodate the
variable (non-linear) element of losses on the distribution system.
The group did not reach a view on whether there are inconsistencies between the BSC
definition of LLF and how LDSOs calculate LLFs, but agreed any such issues around the
relationship of the BSC LLF definition and LDSOs‟ LLF methodologies are outside the scope
of P270.
Retrospection
The P270 Modification Proposal suggested that the P270 solution should be applied
retrospectively, though only back to the first OFTO appointment at the beginning of March.
The group considered the guideline criteria that Ofgem has previously noted in relation to
the retrospective application of changes. The group agreed that retrospection does not
appear to be justified for P270. The Proposer agreed not to include retrospective
application as part of the solution for industry consultation, but noted that they would
further consider this and would like to know the views of industry participants.
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6 Analysis of the Materiality of P270
The group estimated the materiality of the P270 issue by calculating the impact of
applying LLFs to sites to which the BSC does not currently permit an LLF to be applied, but
which meet the criteria of the P270 solution. The only such sites identified by the group
were some of the projects in the first round of the Offshore Transmission arrangements.
Note that the generation projects identified are used as a proxy for their onshore
connections, to which the LLFs would actually be applied under P270.
The approximate annual output of each connection was determined by applying a load
factor of 0.3 (agreed by the group) to the calculated annual output of the generator
(based on its stated capacity). The impact of P270 was estimated by applying the LLF to
the annual output. The P270 materiality is the difference between the output before and
after application of the LLF. An estimate of the monetary value of this materiality was
calculated by applying a price of £60 per MWh.
The overall (net) materiality of the P270 issue is estimated to be 6791MWh. If P270 is
approved this would result in an increase of 0.13% in overall Transmission Losses, based
on approximate total Transmission Losses of 5391000MWh in 2010.
Approximate materiality of P270 issue for Round 1 projects
Project Distribution connection
Size (MW)
Estimated output (MW)
MWh/ year
LLF Materiality (MWh/year)
Materiality (£/year)
Barrow Electricity
North West
90 27 236520 1 0 0
Robin Rigg
East&West
Electricity
North West
180 54 473040 0.97 14191 851472
Gunfleet
Sands 1&2
UK Power
Networks
164 49.2 430992 1.004 -1724 -103438
Sheringham
Shoal
UK Power
Networks
315 94.5 827820 1.004 -3311 -198677
Ormonde Electricity
North West
150 45 394200 1 0 0
Greater
Gabbard
None 504 151.2 1324512 - - -
Thanet UK Power
Networks
300 90 788400 1.003 -2365 -141912
Walney 1 None 178 53.4 467784 - - -
Walney 2 Electricity
North West
183 54.9 480924 1 0 0
Totals 2064 619.2 5424192 6791 407445
Greater Gabbard and Walney 1 do not connect to a Distribution System, and therefore
would not receive an LLF under P270 (and therefore do not contribute to the materiality of
the P270 issue), but are included in the table since they are part of the first round of
projects under the Offshore Transmission arrangements. There are no Distribution
System-connected sites in the currently planned subsequent rounds.
LLFs used are „snapshot‟ values that might be applied to the identified sites based on the
present state of the Transmission System and Distribution Systems. Changes on the
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amount of onshore or offshore generation or demand could affect the LLFs of Remote
GSPs (i.e. in the same way such changes might affect other LLFs).
Robin Rigg was the driver for the raising of P270, and its connection was the first to be
designated as Offshore Transmission under the OFTO regime, at the beginning of March
2011. As such an LLF cannot be applied to either the Robin Rigg generator itself or its
point of connection to the Distribution System. The group estimated the approximate
annual output of Robin Rigg as 473,040MWh per year, based on its stated capacity of
180MW. The group estimated the materiality of the P270 issue in relation to the Robin
Rigg connection as 14191MWh per year by using the LLF of 0.97 that was applied to Robin
Rigg prior to the OFTO regime. This is the approximate volume of energy that would need
to be smeared across users of the Distribution System each year under the baseline or,
under P270, would be shifted into Transmission Losses. The group estimated the
monetary value of this as approximately £850,000 per year.
The Robin Rigg connection is the only significant example of the P270 issue identified
(either currently extant or planned). The materiality of other prospective Distribution
System-connected Offshore Transmission is significantly less than that of the Robin Rigg
connection, but may still be material.
The LLFs applied to projects connected to the UKPN network are based on generic LLFs for
Extra High Voltage sites because there is currently insufficient information to calculate site
specific LLFs. These values are the best estimate possible for the purposes of this
analysis, but the site specific LLFs that would eventually be applied to the sites (i.e. under
P270) could be materially different (increased or decreased), which would affect the
estimate of the materiality.
LLFs of 1 are applied to the projects, other than Robin Rigg, connected to the ENW
network, because these sites are connected very close to „conventional‟ GSPs on the
Distribution System. They will therefore neither materially cause nor relieve Distribution
System losses, so ENW has advised that if they were to receive an LLF it would be 1. This
means that the P270 issue has zero materiality in relation to these sites.
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7 Final Workgroup Discussions
Consultation Responses
11 responses were received to the P270 Assessment Procedure industry consultation.
Respondents included Distributors, Suppliers, Generators and Party Agents. Respondents
were split on the question of whether P270 would be an improvement on the existing
arrangements. A slight majority of six respondents believed that the P270 solution would
not better facilitate the Applicable BSC Objectives compared with the existing Code
baseline.
The group did not identify any significant new arguments either for or against P270 in
consultation responses. CE Electric UK argued that:
Not allocating an LLF to an offshore (i.e. remote) GSP could mean that associated
Distribution System losses are shared between other customers and potentially create
a cross subsidy; and
Without P270 large on-shore generators who have an LLF might be at a competitive
disadvantage compared with off-shore generators who do not.
CE Electric UK believed applying an LLF to remote connections would remove this different
treatment of offshore (remote) and onshore (interconnected) generation and associated
potential cross-subsidies, and P270 would therefore better facilitate Objective (c). The
group did not believe that sharing Distribution System losses between other Distribution
System customers would constitute a cross-subsidy, and considered that P270 would not
directly impact competition between generators because even under P270 no LLF would
be applied to a generator on an isolated piece of the Transmission System, but rather to
the GSP connecting that Transmission System element to a Distribution System.
However, the group considered that if P270 is approved there is a possibility that the
effect of a Remote GSP‟s LLF could be passed through to the generator connected to it
(though they acknowledged a further change might be needed to enable this to occur).
Potential Alternatives
Nine respondents did not believe there were any potential P270 Alternative solutions that
the group should consider. SmartestEnergy suggested that an alternative solution was to
require Settlement metering to be at point of connection to the network onshore. The
group did not believe this would address the issue identified by P270 and agreed that it
appeared to be counter to the intent of the Offshore Transmission arrangements.
CE Electric UK asked whether consideration had been given to whether the losses on
Distribution assets (that result in an LLF calculated by the Distributor) could be separated
from the losses on the offshore (remote) Transmission assets. The group believed that in
principle this could be done, but did not believe it would resolve the P270 issue, i.e. if the
LLF-associated losses are identified the question of who they are allocated to remains.
The group did not believe that separating out the LLF losses as suggested would present
any alternative candidates to receive the impact of such losses, i.e. further to either
Transmission System connectees (under P270) or some or all Distribution System
customers (under the baseline).
The group agreed that there were no potential solutions that should be further developed
or progressed as a P270 Alternative solution.
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Legal Text
Only EDF Energy had significant comments on the P270 Proposed legal text. They
suggested that instead of the suggested change to K1.7.3, to remove the reference to a
Boundary Point, either the current wording „at a Boundary Point‟ should be retained or
wording such as „at a Boundary Point or a Remote Grid Supply Point‟ should be used to
extend K1.7.3 to cover Remote Grid Supply Point without affecting its current meaning.
EDF Energy were concerned that the suggested wording would leave open the possibility
that all Metering Systems “on” a Distribution System, even metering between Distribution
Systems with different owners that might not be used in Settlement, should have an LLF.
They believed this would be unnecessarily burdensome, and it should be made clear that
only Metering Systems used for Settlement require an LLF. The group did not agree that
the suggested text would have the result identified by EDF Energy‟s concern, because the
provisions of K1.7.3 only apply to LLFs, they do not identify where LLFs must be applied.
However, the group considered that the suggestion to add „or a Remote Grid Supply Point‟
would be equivalent to the suggested approach of removing the reference to a Boundary
Point and would result in greater clarity. The group therefore agreed that the legal text
should be updated in line with this suggestion, including any further changes to K1.7.3
needed to support this revised approach.
EDF Energy also suggested that the proposed new definitions should refer to „Contiguous
Main Transmission System‟ instead of „Contiguous Transmission System‟. However, the
group established that this suggestion stemmed from a misapprehension that P270 was
aiming to identify a single Contiguous Transmission System that is the „main‟, onshore
Transmission System.
In fact, the P270 solution leaves open the possibility of multiple Contiguous Transmission
System networks to cater for the possible existence in the future of interconnected
offshore networks which are able to respond to the demand of Distribution Systems in a
similar manner to the main onshore Transmission System. The group therefore agreed
that no change was required to the proposed „Contiguous Transmission System‟ definition.
The group noted that under the proposed text:
Connection of an Offshore Transmission System to two Distribution Systems would
cause the relevant GSPs not to be considered Remote GSPs under P270; and
An isolated onshore Transmission System circuit (e.g. connecting to the main
Transmission System through a Distribution System substation) would be considered a
Remote GSP.
The group also agreed that the other issues mentioned in EDF Energy‟s legal text
comments are out of the scope of P270.
Implementation Impacts
The majority of respondents confirmed that they would not be impacted by
implementation of P270. Electricity North West and UK Power Networks are the two
LDSOs with existing or planned connections on their networks that would be considered
Remote GSPs under P270, and accordingly identified impacts on LLF methodologies and
the LLF calculation. National Grid confirmed an impact due to LLFs being assigned to
Remote GSPs and the consequent effect on Transmission Losses.
Other than the two affected LDSOs and the System Operator, only EDF Energy identified
an impact, as a result of processing new LLFs using existing systems and procedures.
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None of the respondents identified cost or lead time impacts as a result of implementation
of P270.
Implementation Approach
Ten respondents supported the proposed implementation approach. However, one
respondent believed that any changes to Code Subsidiary Documents required to support
the P270 solution should be made at the same time as the necessary changes to the BSC.
The group considered that in the case of P270 no issues would arise from the proposed
approach of implementing the P270 solution in the BSC and then making the supporting
Code Subsidiary Document changes in a subsequent date, but agreed that in principle all
changes should be made simultaneously.
They therefore agreed that if the Code Subsidiary Document changes can be drafted in
time to be included in the P270 Report Phase industry consultation, P270 should be
implemented in both the Code and any affected Code Subsidiary Documents at the same
time, i.e. outside of a standard BSC Release and at an appropriate number of days after an
Authority decision. If Code Subsidiary Document changes cannot be consulted upon in the
Report Phase industry consultation the original, staggered implementation approach may
be employed.
Analysis of Materiality
None of the consultation respondents disagreed with the group‟s approach to the analysis
of the materiality of P270. Only analysis of the materiality of the P270 issue for Robin
Rigg was included in the P270 consultation, though it was noted that similar analysis
would be conducted for other sites that meet the criteria of Remote GSP, albeit Robin Rigg
was understood to be the most significantly impacted existing or planned site.
Respondents commented that the Robin Rigg materiality is a fair representation of the
impact of an OFTO connection on a Distribution System, and though it may not appear
significant in terms of overall Transmission Losses it could be significant for individual
customers. CE Electric UK noted that offshore generation is intended to be a growing
sector, so it is possible that any adverse effects of the current arrangements on Parties
may well be amplified over time.
Western Power Distribution agreed with the assessment of the impact on LDSO losses, but
believed that analysis of potential distortion of competition in generation (between
Distribution System-connected and Remote GSP-connected generators) caused by the
current arrangements might further strengthen the case in support of P270.
Unfortunately WPD‟s response was late, and as such was not discussed by the group at its
final meeting, however no analysis was specified that could be conducted to support the
contention that there is potential distortion of competition in generation. Moreover, the
group agreed, with regard to CE Electric UK‟s comments (in response to question 1), that
P270 would not directly impact competition between generators because P270 would see
LLFs applied to a GSP connecting a generator on an isolated piece of the Transmission
System to a Distribution System. Since the group did not identify a potential for distortion
of competition in generation as a P270 issue, and as such placed no weight on this
argument in its views against the Applicable BSC Objectives, there does not appear to be
any need for supporting analysis in this area.
Any discrimination between generators connected to 132kV Distribution (in England and
Wales) and generators connected to 132kV Transmission (in Scotland and Offshore) had
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been considered during development of the BETTA and OFTO arrangements, and is
beyond the scope of the BSC.
Retrospection
None of the respondents supported retrospective application of the P270 solution.
Electricity North West adopted a neutral stance and noted, as Proposer, that it would
make a final decision on whether the P270 solution should be retrospective at the final
group meeting. The group agreed that there was still no basis for retrospective
implementation of P270.
Therefore the Proposer confirmed that retrospective effect would not be part of P270, and
the P270 solution would have effect only prospectively from the point of its
implementation.
Considerations outside the scope of the BSC
In light of the Authority‟s wider statutory remit the consultation asked for any views from
respondents with regard to benefits or disadvantages of P270 that are outside the scope
of the BSC, though such considerations would clearly be outside the scope of P270.
Six respondents believed P270 would have an effect, two that it would not have any effect
they are aware of, while three were neutral.
Electricity North West provided a summary of the benefits they believe P270 would have
outside the BSC, including the DNO Losses Incentive and its view of the implications of
NGET as offshore System Operator being a party to DCUSA and liable for Distribution Use
of System charges in respect of offshore connections to distribution networks.
Scottish Power‟s response noted that it is possible P270 might alleviate non-BSC problems
but that, as a principle, problems should be solved where they occur, which would not be
the case with P270.
Other comments
Five respondents had further comments on P270. Most had been covered elsewhere in
the assessment of P270 or in the consultation responses. However, the group considered
E.ON UK‟s concern regarding ELEXON interpreting a previous Ofgem decisions in relation
to the OTETWG from January 2008 and the subsequent Ofgem/BERR policy update (see
„ELEXON analysis‟ within the section „Consideration of P270 and P242‟). E.ON noted that
as with any BSC proposal assessment of P270 must be in relation to achievement of the
Applicable BSC Objectives.
The group agreed that P270 must be assessed against the Objectives and considered that
the interpretation and discussion of previous proposals and decisions should not be given
prominence in the assessment of P270, though it should be documented as part of the
detailed record of the group‟s discussions.
In line with this, a group member noted that the remarks relating to CP1343 under „Group
discussions‟ within the section „Consideration of P270 and P242‟ should be noted without
undue regard to the interpretation given to them by the member.
Further discussions
Having considered the consultation responses, a group member reiterated their belief that
the issues identified in relation to P270 could be handled under Distributors‟ LLF
methodologies and, if necessary, changes to the DNO Losses Incentive scheme. However,
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the group noted that the Losses Incentive is firmly tied to LLFs used in Settlement, and to
change this would require a change to the Licence Conditions.
The belief of some members, as previously stated, was that, in practice, P270 was unlikely
to have a significant effect on future connection decisions for offshore networks. The
group clarified that this was based on the view that it is generally not cost effective to
connect large offshore generators to Distribution Systems (primarily due to the network
reinforcement required) since there are currently no incentives (i.e. generally, though
there may be drivers in particular cases).
This means that widespread connection of new Offshore Transmission networks via
Distribution Systems is unlikely. Therefore it appears unlikely that P270 would influence
Offshore Transmission connection decisions because sites that would constitute Remote
GSPs under P270 are unlikely to be created either under P270 or under the current
baseline. However, it is nonetheless possible that smaller generation sites might be
connected via Distribution Systems.
Conclusions and recommendations
Taking into consideration the responses to the P270 Assessment Procedure consultation
and their further discussions, the group agreed the P270 implementation approach and
confirmed their final views on P270 against the Applicable BSC Objectives. The group‟s
final views aligned with their initial views, except that one member believed that a
disadvantage that they had originally ascribed to both Objectives (a) and (b) should only
be against Objective (b), meaning the member now believed P270 to be neutral with
respect to Objective (a). The group‟s final views are set out in the main Assessment
Report document.
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8 Costs and Impacts
Costs
ELEXON Cost ELEXON Service Provider cost Total Cost
Man day Cost
8 £1920 £1000 £2920
Indicative industry costs
Zero industry costs for P270 implementation; any consequent activities (such as
calculation of LLFs by LDSOs) conducted under normal processes.
Impacts
Impact on BSC Agent
CDCA Possible impact due to need to include LLFs in Aggregation Rules for Offshore
Transmission Connection Points
Impact on BSC Parties and Party Agents
LDSOs: LLF calculation and calculated Distribution System losses (and GSP Group Take)
Suppliers and embedded generators: no implementation impact (but effects from impact
on GSP Group Take and/or Line Loss Factors for other connections in the GSP Group)
Impact on Transmission Company
Responsible (as NETSO) for Offshore Transmission Connection Points assigned LLFs
Impact on ELEXON
LLF validation ELEXON audits and approves LLFs calculated by Distributors, and under
P270 would do so for LLFs calculated for remotely connected GSPs
Impact on Code
Section K Classification and Registration of
Metering Systems and BM Units
Amend to allow LLFs for Remote Grid
Supply Points
Sections X Definitions and Interpretation Add and amend definitions to support the
P270 solution
Impact on Code Subsidiary Documents
BSCP25 Registration of Transmission System Boundary Points, Grid Supply Points, GSP
Groups and Distribution Systems Connection Points
BSCP75 Registration of Meter Aggregation Rules for Volume Allocation Units
BSCP128 Production, Submission, Audit and Approval of Line Loss Factors
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9 Workgroup Membership
Member Organisation 22.3.11 10.5.11 27.5.11
Adam Lattimore ELEXON (Chairman)
Dean Riddell ELEXON (Lead Analyst)
Mike Attree Proposer (ENW Limited)
Ben Smith National Grid X
Esther Sutton E.ON UK X
Harminder Basi UK Power Networks
Gary Henderson Accenture
Martin Mate EDF Energy X
Garth Graham SSE (part) X X
Bill Reed RWEnpower
Attendee Organisation
Nicholas Brown ELEXON (Lawyer) X
John Lucas ELEXON (Design Authority) X
Sarah Jones ELEXON (Operational support) X
Bimbola Ayo Ofgem (till 1) X
Paul Jones E.ON UK X X
10 Glossary
Acronym Term
BSCP BSC Procedure
GSP Grid Supply Point
LDSO Licensed Distribution System Operators
LLF Line Loss Factor
OFTO Offshore Transmission Owner
OTETWG Offshore Transmission Embedded Transmission Working Group
P270 – Proposed Legal Text v.0.4
Page 1 of 2 © ELEXON Limited 2011
P270 – PROPOSED LEGAL TEXT
SECTION K: CLASSIFICATION AND REGISTRATION OF METERING SYSTEMS AND
BM UNITS (V33.0)
Amend paragraph 1.7.3 as follows:
1.7.3 For the avoidance of doubt, a Line Loss Factor relating to a Metering System at a
Boundary Point or a Remote Grid Supply Point on a Distribution System where such
Distribution System is indirectly connected to the Transmission System (or, in respect of a
Remote Grid Supply Point, the Contiguous Transmission System) must, when applied to
data relating to such Metering System, converts such data into a value at the Transmission
System Boundary (or, in respect of a Remote Grid Supply Point, the Contiguous
Transmission System Boundary), with such Line Loss Factor to take into account
distribution losses both on:
(a) that Distribution System; and
(b) on the Distribution System by which it is indirectly connected to the
Transmission System (or, in respect of a Remote Grid Supply Point, the
Contiguous Transmission System).
SECTION X: DEFINITIONS AND INTERPRETATION
ANNEX X-1: GENERAL GLOSSARY (V51.0)
Amend Section X by inserting the following definitions in alphabetical order into Annex X – 1 General
Glossary:
"Contiguous Transmission
System":
means any part of the Transmission System that is
connected by transmission assets to two or more GSP
Groups;
"Contiguous Transmission
System Boundary":
means the boundary between the Contiguous Transmission
System and all Plant or Apparatus (including Distribution
Systems and other directly connected Plant and Apparatus)
connected to the Contiguous Transmission System;
"Remote Grid Supply Point": means a Grid Supply Point which is not connected to the
Contiguous Transmission System;
ANNEX X-2: TECHNICAL GLOSSARY (V31.0)
Amend Section X by amending the following definition in Annex X – 2 Technical Glossary:
Line Loss Factor Means a multiplier which:,
(i) when applied to data from a CVA
Metering System connected to a
Boundary Point on a Distribution System,
converts such data into an equivalent
value at the Transmission System
P270 – Proposed Legal Text v.0.4
Page 2 of 2 © ELEXON Limited 2011
Boundary; or
(ii) when applied to data from a CVA
Metering System connected to a Remote
Grid Supply Point, converts such data
into an equivalent value at the
Contiguous Transmission System
Boundary.
P270 – Proposed changes to BSCP25 v.0.1
Page 1 of 4 © ELEXON Limited 2011
P270 – PROPOSED CHANGES TO BSCP25
BSCP25 ‘Registration of Transmission System Boundary Points, Grid Supply Points, GSP Groups and Distribution Systems Connection Points' (Version 6.0)
4.3 Grid Supply Point Registration
REF WHEN ACTION FROM TO INFORMATION REQUIRED MEDIUM
4.3.1 At least 5 WD before the
CPCD1
Agree GSP Id TC LDSO(s) GSP Id Fax/ Email
4.3.2 At least 5 WD before the
CPCD
Submit Registration of GSP Form Part A TC CRA
BSCCo
BSCP25/5.3 Part A ‘Registration of
GSP Part A’, signed by an authorised
person, registered as such using
BSCP38
Fax/ Post/
4.3.3 Within 1 WD of receipt
of 4.3.2
Acknowledge receipt of Registration of GSP
Form Part A
CRA TC Fax/ Email
4.3.4 At the same time as 4.3.3 Check the form has been completed by an
authorised person registered as such using
BSCP38
CRA Internal
Process
4.3.5 Within 1 WD of receipt
of 4.3.2
Inform the relevant LDSO(s) of GSP
registration
Request initial views regarding the allocation
of the GSP to a GSP Group from the relevant
LDSO(s)2 and TC.
BSCCo LDSO(s)
TC
Fax/ Email
4.3.6 Within 2 WD of 4.3.5 Send initial views on the GSP allocation to a
GSP Group
TC
LDSO(s)
BSCCo Fax/ Post/
1 Commissioning Programme Commencement Date: references to the Commissioning Programme Commencement Date in this Section 4.3, are to that of the first circuit associated with the GSP 2 Where the LDSO is operating out of area or it is a shared GSP, other impacted LDSO(s) should be approached for views.
P270 – Proposed changes to BSCP25 v.0.1
Page 2 of 4 © ELEXON Limited 2011
REF WHEN ACTION FROM TO INFORMATION REQUIRED MEDIUM
4.3.7 Within 2 WD of receipt of
4.3.6
Outline new GSP registration details to Parties
concerned and requests opinions on which GSP
Group the GSP should be allocated to with
reference to:
(a) Effect of geographic factors in establishing
Daily Profile Co-efficients
(b) Effect of the size of the GSP Group on GSP
Group Correction Factors
(c) Effect of proximity of Boundary Points on
the value of Physical Notifications and Bid-
Offer Pairs to the TC submitted in relation
to Supplier BM Units
BSCCo Relevant
LDSOs
TC
The Authority
All Suppliers
Consultation paper noting any views
already expressed by LDSO(s) and the
TC
Email/ BSC
Website
4.3.8 Within 10 WD of 4.3.7 Provide opinions as requested Relevant
LDSOs
TC
The Authority
All Suppliers
BSCCo Suggested revisions to the GSPs
comprised in a GSP Group or agreement/
disagreement to an LDSO/ TC view with
reference to geographic factors, the size
of the GSP Group, the proximity of
Boundary Points and which GSP Group
the GSP should be allocated
Fax/ Post/
4.3.9 At next convenient Panel
meeting
Present a paper summarising registration
details for the GSP, opinions of Parties on the
GSP Group allocation and any other
recommendations
BSCCo Panel Panel Paper Internal
Process
4.3.10 Within 1 WD of the
Panel Meeting.
Notify of the Panel’s decision on the allocation
of the GSP
BSCCo Relevant
LDSO(s)
TC
Notification of Panel’s decision Fax/ Email
4.3.11 At the same time as
4.3.10
Complete GSP Registration Form with the
allocated GSP Group ID and send the form to
CRA
BSCCo CRA BSCP25/5.3 ‘Registration of GSP’,
signed by an authorised person,
registered as such using BSCP38
Fax/ Email
4.3.12 Within 1 WD of 4.3.11 Acknowledge receipt of GSP Registration
Form
CRA BSCCo Acknowledge receipt Fax/ Email
P270 – Proposed changes to BSCP25 v.0.1
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REF WHEN ACTION FROM TO INFORMATION REQUIRED MEDIUM
4.3.13 After 4.3.10and at least
20 WD prior to the EFD3
of the associated
MSID(s)
Submit Aggregation Rules for the GSP and
GSP Group Metered Volume in accordance
with BSCP75
Nominated
LDSO
CDCA BSCP75/4.2 form signed by an
authorised person, registered as such
using BSCP38
Fax/ Post /
4.3.14 After 4.3.10 and at least
20 WD prior to the EFD
of the associated
MSID(s)
Submit Metering System Registration Forms
in accordance with BSCP20
LDSO
TC4
CRA BSCP20/4.1 form signed by an
authorised person, registered as such
using BSCP38
Fax/ Post/
4.3.15 After 4.3.10 and at least
20 WD prior to the EFD
of the associated
MSID(s)
For Remote GSPs, initiate the Line Loss
Factor process (BSCP128) by submitting CVA
LLFs for MSID
LDSO BSCCo CVA Long or Short Format data files in
accordance with BSCP128 Appendix 5.
Signed by an authorised person as per
BSCP38
Fax/ Post/
Email and
Electronic
Spreadsheet
4.3.165 At least 10 WD prior to
the EFD
Establish new Aggregation Rule for GSP
Group Take
CDCA Internal
Process
4.3.176 At least 5 WD prior to the
EFD
Check the following:
(a) Metering System Proving Test
associated with the GSP has been
completed successfully in accordance
with BSCP02
(b) Aggregation Rules have been
successfully registered for the GSP in
accordance with BSCP75
(c) New GSP Group Take Aggregation Rule
has been established
(d) Circuit names stated on the GSP
Registration Forms match circuit names
and numbers on the Meter Technical
Details
CDCA
As submitted in 4.3.1
Metering System Proving Test results
Successfully registered Meter
Aggregation Rules
Meter Technical Details
(Where confirmation has not been
provided the GSP registration shall
remain pending.)
Internal
Process
3 The EFD must be on or before the agreed Energisation Date 4 The obligation to register the Metering System lies with the Transmission Company for Offshore Transmission Connection Points, and the LDSO for other Grid Supply Points
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REF WHEN ACTION FROM TO INFORMATION REQUIRED MEDIUM
4.3.187 Within 1 WD of 4.3.176 Confirm checks made in 4.3.176 CDCA CRA
Fax/ Email
4.3.198 At least 4 WD prior to the
Energisation Date
If confirmation in 4.3.187 is not received,
inform the TC not to energise the circuits and
agree a new Energisation Date
CRA TC
LDSO
Confirmation that the circuits should
not be energised and agreement of a
new Energisation Date
Post/ Fax/
4.3.201
9
Prior to the EFD of the
associated MSID(s) and
on completion of 4.3.187
Inform the TC of the EFD of the Metering
System(s) associated with the GSP and
authorise the TC to energise the connection on
or after this date
CRA TC Confirmation of EFD and authorisation
to energise on or after this date
Fax/ Post/
4.3.210 On or before EFD of the
associated MSID(s)
Provide Party and BSC Agents with standing
data reports
CRA LDSO
TC
BSC Agents
BSCCo
Standing data reports of data entered
onto the systems (CRA-I007)
Electronic
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BSCP75 ‘Registration of Meter Aggregation Rules For Volume Allocation Units' (Version 12.0)
4 Appendices
4.1 Typical Configurations and Aggregation Rules for Volume Allocation Units
4.1.1 Overview
In order to calculate the Metered Volume for a Volume Allocation Unit,
Aggregation Rules have to be submitted by Parties to enable metered data values to
be aggregated to the appropriate Metered Volume. The responsibilities are detailed
in Section R of the Code. This means that Parties have an obligation to register
Aggregation Rules with the CDCA for the following Volume Allocation Units in
accordance with this BSCP (the Volume Allocation Units themselves are registered
with the CRA):
BM Units (other than Interconnector BM Units and Supplier BM Units)
Grid Supply Points (including Remote Grid Supply Points)
GSP Groups
Interconnectors
Listed below are examples of the typical configurations of the four Volume
Allocation Units that require Aggregation Rules to be submitted. Aggregation Rules
are submitted using the Metering System ID and metering subsystem ID and, where
appropriate, BM Unit ID, GSP ID, GSP Group ID and Interconnector ID.
The identifier for a specific flow consists of the Metering System ID, the metering
subsystem ID and the measurement quantity.
The Custom and practice is that Export Meters are used to measure flows
from Plant or Apparatus and Import Meters are used to measure flows to
Plant or Apparatus.
Any flow on an Export Meter is classified as AE. Any flow on an Import
Meter is classified as AI.
In all cases, a net flow measured by a metering subsystem will be calculated
as [AE-AI]. Hence, a net flow from Plant/Apparatus will be treated as
positive and a net flow to Plant/Apparatus will be treated as negative.
Therefore the Volume Allocation Unit which has a net Import will be
treated as negative and a Volume Allocation Unit which has a net Export
will be treated as positive.
All net flows measured by a metering subsystem which are to be accounted
for in a given Volume Allocation Unit will be summed. This will give an
overall net flow into or out of the given Volume Allocation Unit.
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All net flows measured by a metering subsystem which are to be accounted
for in any other Volume Allocation Units that are associated with the given
Volume Allocation Unit should be subtracted from the above summated net
flow. The outcome of the above two operations will be the net flow for the
given Volume Allocation Unit.
In the case of GSP Group Takes, a further set of net flows need to be subtracted
from the summated net flows derived in the above steps. These are the net flows
measured by metering subsystems of CVA registered Volume Allocation Units
which are embedded within the GSP Group. The prime responsibility for
identifying these CVA registered Volume Allocation Units lies with the CDCA
(rather than with Parties). However, the CDCA will fulfil this responsibility by
requesting LDSOs to submit Aggregation Rules for GSP Group Take for their
authorised area and the LDSOs shall comply with any such request.
In the illustrations that follow the above logic is used. However, the diagrams show
metering subsystems, rather than individual meters, registers or channels.
4.1.6 Grid Supply Points and GSP Group Takes
GSPs are a number of Systems Connection Points at the same location at which the
Transmission System is connected to a Distribution System. The submission of
Aggregation Rules for GSPs and GSP Groups are the responsibility of the
Distribution System Operator. The submission of Aggregation Rules for GSP Group
Take is the responsibility of the CDCA.
Note that the term Grid Supply Point (as used in the BSC and in this BSCP) includes
Offshore Transmission Connection Points i.e. points at which the Offshore
Transmission System connects to an onshore Distribution System. The process for
submitting Aggregation Rules for Offshore Transmission Connection Points is the
same as for other Grid Supply Points.
Section 4.1.7 describes two different examples of a shared GSP. Section 4.1.8
describes a typical GSP which includes a Distribution Systems Connection Point and
GSP Group Take.
Sections 4.1.9-4.1.11 describe different scenarios with embedded Distribution
Systems where there is more than one Distribution System Operator within a single
GSP Group.
Section 4.1.17 describes considerations relating to a Remote GSP.
4.1.17 Remote GSPs
The submission of Aggregation Rules for Remote GSPs is the responsibility of the
Distribution System Operator. The term Grid Supply Point (as used in the BSC and
in this BSCP) includes Remote GSPs, i.e. GSPs that meet the criteria of a Remote
GSP as defined in the BSC. The process for submitting Aggregation Rules for
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Offshore Transmission Connection Points is the same as for other Grid Supply
Points.
Before Aggregation Rules can be submitted for Remote GSPs the Remote GSPs
have to be registered in accordance with Section K of the Code and BSCP25.
Aggregation Rules for Remote GSPs are defined in the same way as Aggregation
Rules for other GSPs (as described in section 4.1.6) except that Aggregation Rules
for Remote GSPs shall include the application of appropriate (Distribution) LLFs.
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BSCP128 ‘Production, Submission, Audit and Approval of Line Loss Factors’ (Version 3.0)
3. SUPPORTING INFORMATION
3.1 LLF Methodology Principles
All LLF methodologies are required to comply with the Principles described below:
1. LLFs shall be calculated using a generic (non Site Specific) method except for:
(a) Sites that are connected at Extra High Voltage (EHV); or
(b) Where the customer has requested a Site Specific LLF, and the LDSO is
in agreement; or
(c) Sites that are Remote GSPs.
2. All LLFs shall be calculated to at least 3 decimal places and submitted to 3
decimal places.
3. All Site Specific LLFs shall account for Technical Losses only.
4. All Generic LLFs shall account for all losses (Technical and Non Technical).
5. Site Specific losses and the total Grid Supply Point Group (GSPG) losses shall
be considered in the calculation of Generic LLFs.1
6. Non-EHV Generic LLFs for Import and Export at the same site where the
voltage level is the same shall have the same values.
7. There shall be no more than 2 Low Voltage (LV) and 2 High Voltage (HV)
Generic LLFC Groups, in each GSPG, and at least 1 Generic EHV LLFC
Group.
8. As a minimum, Generic LLFs shall be calculated separately for Day and
Night.
9. LDSOs shall utilise Settlement data from a Settlement Run at R3 or greater
and from a complete 12-month period, for calculating Generic LLFs. The 12-
month period to be used shall be the BSC Year2 3 years prior to the BSC Year
for which the LLFs are being calculated.
10. Adjustments to calculation or application of LLFs, to take into account historic
market wide issues noted in the BSC Auditor’s latest Report, can only be made
if agreed to be appropriate by the Panel.
1 This principle allows Site Specific Losses to be calculated individually or in aggregate and then used in the calculation of Generic LLFs. 2 This principle only applies to the calculation of Generic LLFs. The BSC Year is 1 April to 31 March, LLFs for use in the BSC Year
commencing 1 April 2011 should be calculated using the Settlement Data from the 2008 BSC Year, 1 April 2008 to 31 March 2009.
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11. Robust error detection and correction processes shall be in place throughout
the calculation and submission of LLFs.
12. All Generic LLFs shall be re-calculated at least every 2 years.
13. All Site Specific LLFs shall be re-calculated when there has been a relevant
change to the site or network, and at least every 5 years.3
14. No changes shall be made to approved Generic LLFs mid year. Annual
updates will have an effective from date of 1 April. Where default LLFs have
been applied due to an audit failure, these may be replaced with approved
LLFs on a prospective basis as determined when the LLFs resubmitted by the
LDSO have been approved by the Panel.
15. No retrospective changes shall be made to approved Site Specific or Generic
LLFs other than to correct material manifest errors.
16. Changes shall only be made to approved Site Specific LLFs mid year if there has been a
material change affecting the site; and the revised LLFs have been approved by the Panel.
Annual updates will have an effective from date of 1 April. Where default LLFs have been
applied due to an audit failure, these may be updated to the approved LLFs on a prospective
basis as determined from time to time by the Panel.
3 Appendix 3.4 provides clarification on how this should be implemented.