Part of the BRE Trust
Integrating PV into Buildings
the main options
Steve Pester
Building Research Establishment
BRE and Low CarbonTechnology
– Monitoring & field trials
– Research
– Publications
– Certification (BREG, e.g. MCS)
– Grant schemes
– Product testing
– Modelling SAP, SBEM
– Consultancy for individual clients - energy companies, developers, architects, LAs, government
Definitions
PV (or BAPV)
BIPV
SAPASundogOdersun Photo: BRE
BRE BRE
BIPV applications
– Tend to be newbuild
– Retrofit is possible
3S Swiss Solar Systems AG
Solarcentury
Some Drivers
– European Directive on the energy performance of buildings (2010)– Calls for low energy building designs by 2020,
requiring:• New materials• Super-efficient appliances• Renewable Energy systems
– UK Government ambition to achieve 22GW installed PV by 2020
• Main tools: FITs, ROCs, possibly Green Deal– Clients with BREEAM or other sustainability agenda
For many, this type of PV installation will be part of the solution…
BRE
…but there is a choice
Rotterdam Station
Financial trends of BIPV
– Historically, BIPV seen as too expensive
– Cost of silicon has fallen 50% in past 2 years
– So BIPV costs are reducing in-line
– local building standards & regs apply, so product designs are also localised
– But need to factor in value of other functions of BIPV:• Weather protection• Thermal insulation• Solar shading• Sound reduction• Materials replaced
The cost of NOT investing up front– The choice is between investment costs and operating
costs
– Well-designed & installed PV will last the lifetime of most commercial structures (>25 years)
– Investing up front reduces uncertainty of operating costs
– Where will electricity prices and carbon taxes be in 25 years?
– Will commercial buyers and tenants prefer a building with a well designed BIPV system for their company?
Solar Resource in Europe
Annual solar energy on horizontal plane
kWh/m2
[Ubbink Nederland]
Effect of orientation
Courtesy of MCS, Guide to the Installation of Photovoltaic Systems, 2012
Rough estimates of energy production using PV area
Annual Electrical Energy Produced:
Approx. H0 x A x 14% kWh per year
where:
H0 = Annual Global Radiation on Horizontal Plane (available from PVGIS or Met Office)
A = Active area of collector
(Assumes appropriate orientation, module efficiency 16%, PR 0.8, 30º tilt correction)
Health Warning: If you need accurate figures get trained on a modelling package or consult a professional!
Building energy factors
Renewable Electricity
Renewable Heat
Controls & Appliances
Services - on gas & elec?
Fabric
Design (incl. Passive solar)
BIPV needs early consideration:fundamental factors
Applications and product types
Bringing PV into the world of construction
Who’s involved?
Typically:– the Client – often the key driver!
– Architects & Designers
– Renewables Consultant
– PV / ST Supplier / Installer
– Curtain Wall Manufacturer
– General Contractor / Glazing Contractor
– Electrical Engineer
Good project management is key!
Brief round-up of product types
– In-roof mountings with standard modules
– Tiles, slates, shingles
– Membranes
– Transparent componentso Glass/glass laminateso Laser-etched glass
– Facades
In-roof mountings with standard PV modules
– Cheapest form of integration
– The building-integrated part is the mounting
– Improved appearance over external frames
– Offsets some materials
– Needs careful design of ventilation
IBC mounting on cedar roof with Sanyo modulesPhoto: Chelsfield Solar
Tiles, slates, shingles
– Mostly PV products
– Generally newbuild or roof refurbs
– Can be contrasting or matching
– Some cost recovered by replacement of tiles
– Big advantage: These can be installed by a roofer with little extra training
Photo: Solarcentury
Photo: SundogPhoto: Solar Slate Ltd
Roofing membranes
– Ideal for large roof expanses
– Adhesive mounting – no frame, low mounting cost
– Very low roof loading (~4kg/m2)
– Normally need at least 3°slope
– Generally fairly low power density (~20m2/kWp)
– factory-fitted electrical connections beneath membrane
Photo: Alwitra
Transparent components: Glass-glass laminates
– Especially useful for solar gain control
– Cell spacing chosen for balance of:o Shadingo Electricity generationo Light levels
Photo: Sapa Building System
Double-glazed PV modules – shading & insulating
Diagrams: Schott Solar
Laser etched transparent PV
– Usually amorphous silicon
– Etching gives or enhances transparent effect
PV Pavilion, GermanyPhoto: Odersun
Sunshade on BRE Innovation ParkPV: Polysun , Photo: BRE
Sun Shades
– Will become more common with tighter building regulations
– Fixed or moveable
– Moveable may be unpowered
Photo: Odersun Solar Decathlon. Photo: Jim Tetro
Irish Lights. Photo: Romag
Opaque Facades
– Materials offset can be significant
– Large potential in retrofit market
BIPV Facade (Retrofit)Photo: Schueco
Volksbank, Karlsruhe
- Weatherproof skin- Noise barrier- Sun shading- Heating & cooling- Electricity
Industrial units
– Opaque facade modules
– Customised colours
Photo: Sunways
Innovative products & trends
– Better integration into standard building components
– More CIGS– OPV ?
– V. Low cost– Recyclable– Good low light performance– V. Light weight– Non-toxic
Ceramic BIPVPV: System Photonics
OPV on ConcretePhoto: Heliatek and Reckli
– More Colours & textures
– More Transparent components
BIPV Windows (Retrofit)Photo: Schueco
Further info– BRE: (www.bre.co.uk)§ BRE Information Paper on BIPV (IP11/12)§ National Solar Centre§ Innovation Parks:
• Garston Park evolving• New parks – Scotland, Wales, China, Brazil
– Design-Build-Solar website (www.design-buildsolar.com)
– Shows & Conferences: Intersolar, EUPVSEC, Ecobuild
– Trade Bodies & Associations:World: Global Solar CouncilEurope: EPIA, ESTIFUK: STA, BPVA, REA
Thanks for your attention... Questions?BRE Consultancy:[email protected]+44 (0) 1923 664 000
Steve Pester: [email protected]
BRE Global Certification: MCS Installers & Products:www.greenbooklive.com/[email protected]@bre.co.ukTel: +44 (0) 845 6181514
Thank you!
Romag