wind integration in ercot
TRANSCRIPT
Thoughts on ERCOT’s Wind Generation Experience
• More wind, more wind, more wind• Better reliability metrics• Reduced ancillary services requirements
2
Geography
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H
Mexico
D
SA
ERCOT Annual Energy by Fuel Type
4
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Annu
al G
ener
atio
n M
ixOther
Natural Gas
Wind
Coal
Nuclear
Wind Output and Estimated Curtailment
5
8.4%
17.1%
7.7%
8.5% 3.8%1.1%
0.5%
1.0%
1.6%
2.5%
0
10
20
30
40
50
60
70
2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Win
d Pr
oduc
tion
& C
urta
ilmen
t (TW
h)
Estimated Curtailment
Output
More wind producing more
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0%
5%
10%
15%
20%
25%
30%
35%
40%
0
5
10
15
20
25
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Annu
al C
apac
ity F
acto
r
Inst
alle
d W
ind
Gen
erat
ion
(GW
)
Installed Wind Capacity
Annual capacity factor
2017 Unit Specific Wind Generation Capacity Factor
7
0%
10%
20%
30%
40%
50%
60%
Capa
city
Fac
tor
InService Year
Coastal Panhandle All Other Wind
Improved Reliability Metrics
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Declining Requirements for Ancillary Services
9
0
1
2
3
4
5
6
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
Rese
rve
Qua
ntiti
es -
GW
RegDown NonSpin Responsive RegUp
Key Enablers
• Common carrier model for Transmission• Centralized forecasting of wind output
– for every wind generator– ramp events
• Real-time output variations accommodated
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ERCOT Transmission
• All loads pay for all transmission • Generators are not required to make any transmission
investment past their step-up transformer• Public policy choice to build out transmission system in
advance of need– CREZ investment - $7B
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$0
$10
$20
$30
$40
$50
$60
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Rate
($ p
er k
W -
year
)
Transmission Costs
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$0.0
$0.5
$1.0
$1.5
$2.0
$2.5
$3.0
$3.5
$4.0
0
10
20
30
40
50
60
70
80
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
Annu
al T
COS
($Bi
llion
)
Aver
age
4CP
Load
(GW
)
Indicative – Not Actual
Transmission and Energy costs
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0
1
2
3
4
5
6
7
8
9
0
10
20
30
40
50
60
70
80
90
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
$ pe
r MBt
u
$ pe
r MW
h
RT Load weighted Avg price Average transmission cost Gas
Indicative Transmission CostsNot Actual
ERCOT Wind Forecasts
• Hourly forecast of wind production potential for each Wind-powered Generation Resource (WGR) updated hourly, for next 168 hours. (STWPF)
• Determine probability distribution of the hourly production potential from all wind-power in ERCOT for each of the next 168 hours. (TEWPF)
• WGR provide turbine availability via outage scheduler
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ERCOT Wind Forecasts - WGR requirements
• Install and telemeter to ERCOT site-specific meteorological information necessary to produce the STWPF and TEWPF forecasts.
• ERCOT requires the following data be provided from each WGR every five minutes:
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MW AverageWind SpeedWind DirectionTemperatureBarometric Pressure
HSL AverageNum of Turbines OnNum of Turbines OffNum of Turbines UnknownCurtailment Flag
Accommodating variable output
• ERCOT dispatch executes every 5 minutes• WGR High Sustained Limit (HSL), when not curtailed, to be
telemetered as equal to the WGR’s current meter reading• When curtailed, WGR’s receive a curtailment flag from
ERCOT along with their Base Point (dispatch level)• When WGR is curtailed, the HSL to be telemetered is the
expected output, but for the curtailment• WGR ramping when curtailed limited to 20% per minute,
unless installed before 2009 and have a good excuse
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Negative prices
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0
100
200
300
400
500
600
700
800
900
1000
2011 2012 2013 2014 2015 2016 2017
Hou
rs
WEST Only ERCOT Wide Other
In Summary
• ERCOT’s experience– More wind, more wind, more wind– Better reliability metrics– Reduced ancillary services requirements
• Enablers– Common carrier model for Transmission– Centralized forecasting of wind output– Real-time output variations accommodated
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