oxpv ses sig bipv workshop 20150429 short

Towards near zero energy buildings – challenges and solutionsApril 2015

What is BIPV?

29/04/15 SES SIG BIPV workshop 2

Definition from CENELEC BIPV specification (prEN 50583)

‘Photovoltaic modules are considered to be building-integrated, if the PV modules form a construction

product providing a function as defined in the European Construction Product Regulation CPR 305/2011.

Thus the BIPV module is a prerequisite for the integrity of the building’s functionality. If the integrated

PV module is dismounted (in the case of structurally bonded modules, dismounting includes the adjacent

construction product), the PV module would have to be replaced by an appropriate construction product.’

Different

mounting

categories of

BIPV

Other pre-standards activities:

• ISO DIS 18178 Glass in building — Laminated solar photovoltaic glass

• IEC 62980 Ed.1 Photovoltaic modules for building curtain wall applications

Oxford PV introduction

SES SIG BIPV workshop 329/04/15

Perovskite represents the most significant breakthrough in solar technology since the 1970s

Increasing photovoltaic cell efficiency is today’s

#1 lever for further cost reductions of solar power…

…but the efficiency of market-dominating crystalline

silicon and established thin-film technology has

plateaued

1970 1980 1990 2000 2010 2020

0%

10%

20%

30%

20.1%

perovskites

silicon

thin-film

(CdTe, CIGS)

(no further

progress)

Photovoltaic cell efficiency records

Perovskite takes solar technology to a whole new

level :

• Extremely fast progress in R&D demonstrates

game-changing potential

• Theoretical maximum (>30%) far exceeds silicon

for single junction cell

• Uses abundant, inexpensive materials, with a

simple cell structure, low wastage and low

manufacturing cost

• Printed as a second layer on top of standard PV

cells to increase absorption and efficiency


Target markets worth $110bn annually, and growing quickly

Tandem boost to existing silicon PV ($100bn market)

short-term launch,

low-capital,

mass market

BIPV– Building Integrated PV ($10bn market)

mid-term,

high-margin,

niche market to begin with

1

2

Future

stand-alone

perovskite

solution


Towards near zero energy buildings


Drivers for near zero energy buildings

The climate and energy package is a set of binding

legislation which aims to ensure the European

Union meets its ambitious climate and energy

targets for 2020.

These targets, known as the "20-20-20" targets, set

three key objectives for 2020:

• A 20% reduction in EU greenhouse gas

emissions from 1990 levels;

• Raising the share of EU energy consumption

produced from renewable resources to 20%;

• A 20% improvement in the EU's energy

efficiency.

The Energy Performance of Buildings Directive

2010/31/EU (EPBD recast) is the main legislative

instrument driving ‘Nearly Zero-Energy Buildings’.

According to Article 9 of the Directive: “1. Member

States shall ensure that:

• by 31 December 2020, all new buildings are

nearly zero-energy buildings; and

• after 31 December 2018, new buildings

occupied and owned by public authorities are

nearly zero-energy buildings.”


EU climate change targets and the Energy Performance of Buildings Directive

EU 2020 targets driving EPBD

fabric energy efficiency

efficient heating and

coolingCarbon

Compliance

Zero

Carbon

on-site

renewables

allowable

solutions

Energy hierarchy- Encouraging the right behaviour

Focus on fabric first

Then heating and cooling

Then renewables can really

contribute to energy reduction

Don’t forget energy efficiency

2020 CO2 emission reduction

targets only possible if

renewables contribute more,

and/or window to wall ratio

reduces


Adapted from Zero Carbon Hub’s hierarchy triangle

As targets tighten,

diminishing returns hereHierarchy underpinned by energy efficiency

Extra challenges for BIPV in the architectural world

First and foremost we are an

architectural product

• Aesthetics

• Performance

• Lifetime

We need to fit into the

construction industry value chain

• Which means we cannot add

lots of extra steps to install

BIPV products

• BIPV IGUs replacements

must follow industry norms


We have to have products that

are flexible in size

• Windows are typically 1.5m

wide, height from 2.75m up to

4m

• Some facades are now using

double width and height

glazing 3m x 6m

If we do not meet this,

we have no BIPV

product

Know your customer

and target marketProduct flexibility

Opportunities for BIPV versus standard PV


Relative contribution in CO2 emissions reduction with and without BIPV glazing

heating & cooling

49.5%49.5%

fabric performance

Today

on-site renewables

~1%

Standard PV

For tall buildings

aesthetic look of

standard PV limits

application, other

renewables often

not an option

With

Oxford PV33%33% 33%

Now means more

flexibility on fabric

performance and

heating/cooling

design

Note: Savings relative to Part L

Why BIPV can make a difference

20 Fenchurch Street

• Regulated load 6,477 MWh/yr

• Façade area ~ 34,000 m2

• Standard PV <500 m2

52-54 Lime Street*

• Regulated load 1,600 MWh/yr

• Façade area ~ 26,000 m2

• Standard PV <200 m2


Vertical solar farms

20 Fenchurch Street

2.3 MWp

1,180 MWh/yr

606 tCO2/yr saving

Leadenhall Building

2.1 MWp

1,001 MWh/yr

499 tCO2/yr saving

Vision &

spandrel

Vision only

Vision &

spandrel

52-42 Lime Street

2.1 MWp

940 MWh/yr

451 tCO2/yr saving

* The Scalpel is built to newer building regulations & following energy hierarchy

Vision: 6%, spandrels: 15%

Building data from publicly available

sources

Impact of differing vision and spandrel ratios


Example of the Leadenhall Building

• Spandrels alone reduce emissions annually by 350-500 tonnes CO2

• Ratio does not need to compromise architectural intent (if thought about early enough in design concept)

• Additionally could offset pressure to reduce window to wall ratio

Leadenhall

Building

Leadenhall

Building

Leadenhall

Building

Glass vision:spandrel ratio Vision only 75:25 60:40

Installed power (MWp) 2,099 2,888 3,361

Energy generation (MWh/yr) 1,001 1,474 1,721

Building energy saving (%) 14% 21% 25%

Building CO2 saving (tonnes

CO2/yr)

499 754 864

Building CO2 saving (%) 15% 23% 26%

Just under 50%

generation from

spandrels

Just over 60%

generation from

spandrels

NB: Saving relative to Part L notional building

Balance of System (BOS) Steering Group

We did not have the answers- so

we asked for help:

• What mitigation is needed to

address challenges?

• Output: a document available

to anyone

We are now involved PV

standardisation (member for IEC

TC 82)

Special thanks to Rick Wheal

of ARUP for suggesting to set up

a SIG

Practically addressing BIPV at scale


Oxford PV perovskite facts in a slide


To generate 1MW

takes <20 litres

The Shard would

require 66 litres

UK PV installed

capacity (5GW)

~100,000 litres

World PV

forecast for 2015

(53GW)

~1,000,000 litres

Or a water cooler

bottleOr a tank of fuel

Or just less than

a rail tanker

Or an Olympic

swimming pool

half filled

oxpv ses sig bipv workshop 20150429 short

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