Building Integrated Photovoltaics - BIPV

BIPV BASICS

Acronym of BIPV (Building Integrated Photovoltaics) refers to photovoltaic systems integrated within an object. It means that such systems are built/constructed along with an object. Yet, they could be built later on. Due to specific task cooperation of many different experts, such as architects, civil engineers and PV system designers, is necessary. According to how and where such systems are built, whether into the facade or in the roof, the following BIPV systems are recognized:

Facade or roof systems added after the building was built,
Facade integrated photovoltaic systems built along with an object,
Roof-integrated photovoltaic systems built along with an object,
Shadow-Voltaic PV systems also used as shadowing systems, built along with an object or added later.

Facade integrated solar modules in Cologne, Germany
(courtesy: Architekturbüro Hagemann)

Train station Stillwell Avenue, New York City, roof integrated transparent BIPV system
(courtesy: Arnold Glas)

In the case of facade or roof systems the photovoltaic system is added to the building after it was built. These low powered systems of up to some 10 kW are usually integrated into the south facade. Facade integrated photovoltaic systems could consist of different transparent module types, such as crystalline and micro-perforated amorphous transparent modules. In such case a part of natural light is transferred into the building through the modules. Solar cells are available in different colours; therefore, there is no limitation for imagination of the architect or the designer. We can say that such constructed buildings give the term architecture a completely new meaning. Roof-integrated photovoltaic systems are integrated into the roof; the roof is covered with transparent photovoltaic modules, or they are added to the roof later. Such systems are added to a flat roof, or on a tilted roof usually only if the building is small. It is possible to use tiles, which integrate solar cells.

Akademie-du-Mont-Cenis, Herne, Germany, PV system integrated into building envelope
(credit: pvresources)

Photovoltaic systems could be used for shadowing, where photovoltaic modules serve as Venetian blinders. In some of such cases photovoltaic modules tilt angle could be adjusted manually or automatically allowing for shadowing the building and/or photovoltaic module efficiency optimization. Such systems are also known as shadow-voltaic systems. The best results and efficiency can be reached with systems, which are tightly integrated into the passive solar buildings; however, the use of active solar systems is an additional possibility. This is where the modules are partially transmitting allowing natural light to penetrate the building. Undoubtedly, such systems challenge even the best of architects. High level of expertise is required for successful BIPV systems planning, not only in regard to architecture, but also to civil and photovoltaic engineering. The projects realised in the past show that successful BIPV systems designing is based heavily on technical experience and knowledge. Poorly designed systems usually have to be redesigned or repaired later, consequently swelling maintenance costs and lowering system efficiency rate.

FROM MODULE TO BIPV SYSTEM

BIPV general

In BIPV applications different types of modules (depends on application) can be used: classic (framed) modules, flexible crystalline or thin-film on metal substrate, roof-tiles with solar cells, transparent monocrystalline modules, modules with coloured solar cells, semitransparent micro perforated amorphous etc. Upon customer request almost all module (mechanical and electrical) parameters can be customized. Customization include module shapes, cell type and colour, cell transparency, laminate construction, laminate/module size, heat/noise isolation properties, module voltage and peak power etc. Limitation during production represents usually only laminator - largest laminators allow production of laminates up to 5 square meters of area in one piece. Exact shadowing analysis should be made before the system is constructed, high temperature conditions should be avoided by crystalline modules (decreased efficiency).

Facade integrated modules

Most common realized as "curtain wall", or facade mounted modules. "Cold" and "warm" photovoltaic facades possible. In BIPV facades different types of modules can be used: classic modules, transparent or semitransparent modules (crystalline or microperforated amorphous modules). Shadow-Voltaic system is also very often part of a BIPV facade. Modules can be fixed or mounted on tracking structures - manual tracking-combined with shadowing system, or automatic tracking systems possible.

Facade integrated photovoltaic system.
Blue coloured part of the facade are modules.
(credit: Thyssen Solartec/Franzen group)

Roof integrated modules

As roof-integrated modules usually laminates without frame are used. Special types are solar roof tiles or shingles. For details please visit solar roof-tiles section. As roof integrated modules other module types can also be used for example: flexible modules, transparent or semitransparent modules, thin film modules etc.

BIPV EXAMPLES

Building Integrated Photovoltaics - information leaflet written by Hespul, APERe, ZREU, CLER experts gives very good overview about BIPV systems and solutions.

BIPV - An overview of existing products and their fields of application - SUNRISE is a Co-ordination Action type project financed within the 6^th Framework Programme. The main aim of the SUNRISE project is to support the key objective to reduce costs of PV systems by achieving further growth to compete in the liberalised energy market of the future.

SOLAR GLAZINGS AND LAMINATES

Solar glazings

In photovoltaic applications (also in BIPV systems) low iron tempered glass is usually used. Glazing can be made as simple glass/glass laminate or as complex isolation glass/glass laminate. Special laminates with coloured back sides have also been produced. Due to safety requirements for lamination usually PVB foil instead of EVA foil is used -> especially for laminates used in transparent roofs. PVB have been used for decades in automotive industry - laminated safety windscreen glass. Laminate can consist of monocrytalline cells, thin film cells or from transparent cells. For details please see transparent solar cells and modules section or module section.

Commercially available transparent modules

Arnold Glas - VOLTARLUX® products are based on ASI thin-film photovoltaic modules supplied by SCHOTT Solar. Web site also available in:
ertex solar - the goal of ertex solar is fabrication of high quality solar modules, to extend the opportunities for utilizing photovoltaics in architectural design as well as building integration. Web site also available in:
Scheuten Solar - Scheuten Solar is a leading producer of high quality standard glass-tedlar Multisol® PV modules and custom made glass-glass Optisol® PV modules. Web site also available in:
SCHOTT Solar - glass laminates and double glazed units incorporating ASI® Glass solar panels. Web site also available in:
Saint Gobain Glass - high energy transmittance patterned glass. Web site also available in: ...

ARCHITECTS AND BIPV SOLUTIONS

Architects

Architekturbüro Hagemann - since 1991, Architects and Consultants working in the field of BIPV. Web site also available in:
Rolf Disch - Rolf Disch Solar Architecture commands an immense amount of experience in not only housing and community building, but as well in planning commercial, office, hotel and exhibition space – and last but not least social institutions. Web site also available in:
BEAR Architecten - group of Architects with many BIPV and sustainable buildings projects realized worldwide. Web site also available in:
KISS + Cathcart Architects - Since 1983, US architects Kiss + Cathcart has been designed successfully operating BIPV systems.
RELAB - RELAB, renewable energy laboratory, specializes in Building-Integrated Photovoltaics (BIPV) and Building Integrated Wind projects in urban settings.
Solar Design Associates - Solar Design Associates (SDA) is North America's oldest, largest, and most respected building design firm dedicated to the artistic integration of solar energy in homes and buildings.

BIPV solutions

Sanyo Solar Ark - the design of the Solar Ark was inspired by the vision of an ark embarking onto a journey toward the 21st Century. Only four columns are used to support the entire structure, thus giving the impression of floating in the air. Web site is also available in:
Solarsiedlung - Municipal Housing in Freiburg, Germany. Web site available in:
Solarcentury - UK Company specialized for designing and building of BIPV systems.

COMMERCIAL AVAILABLE BIPV PRODUCTS

Abakus Solar - Abakus Solar offers glass-glass-modules, according to requirements we also provide customized and turnkeyed solutions. Web site also available in:
American Warming and Ventilating - fixed or controllable Shadovoltaic external glazed solar shading system that may be installed either vertically or horizontally in front of the facade.
Colt International - fixed or controllable external solar shading systems.
LOF Solar - LOF SOLAR Corp. produces coloured solar cells in variety of shapes and colours. Web site also available in:
Powerquant - design Modules with polycrystalline DIAGON solar cells allow unique design for individual solutions of building-integrated photovoltaics. Web site also available in:
SolarFrameWorks - specializing in proprietary innovative solar power solutions that are light weight, have no roof penetrations, and have high wind resistance.
Solarintegrated - Solar Integrated provides turnkey PV-solutions for large low-slope roofs as are common for retail outlets, logistic centers and industrial facilities as well as municipal buildings and landfill sites.
SOLARTEC - SOLARTEC is concentrated on production of high quality and customized photovoltaic solar cells, sales of PV system facilities and PV projects. It offers crystalline solar cells in variety of colours suitable for wide range of BIPV applications. Web site also available in:
Solon - wide portfolio of products also includes fully roof integrated sollutions. Web site also available in:
MAGE Sunovation - the leading supplier of lightweight plastic solar modules worldwide. Web site also available in:
Sunways - among others Sunways also produces coloured solar cells for demanding BIPV applications. Web site also available in:
Uni Solar - Uni-Solar offers wide range of photovoltaic products and solutions. BIPV related photovoltaic modules based on a-Si are also part of their product range. Web site also available in:
U.S. Green Energy Corp. - USGE’s vision is to provide an affordable alternative energy through the beauty of solar roofing and siding as an architectural and construction friendly, exterior building products which are integrated with solar electric and solar thermal components.

SOURCES AND ADDITIONAL INFORMATION

Books

	Hagemann, I.: Gebäudeintegrierte Photovoltaik: Architektonische Integration der Photovoltaik in die Gebäudehülle; Rudolf Müller Publisher. Köln, ISBN 2002, ISBN 3-481-01776-6.
	Prasad, D., Snow, M.: Designing with Solar Power: A Source Book for Building Integrated Photovoltaics (BIPV); Earthscan, London 2005, ISBN 1-844071-47-2.
	Gaiddon, B., Kaan, H., Munro, D.: Photovoltaics in the Urban Environment: Lessons Learnt from Large Scale Projects; Earthscan, London 2009, ISBN 978-1-84407-771-7.

Reports

	Eiffert, P., Kiss, G.J.: Building-Integrated Photovoltaic; Designs for Commercial and Institutional Structures - A Sourcebook for Architects.
	Kiss, G.J., Kinkead, J.: Optimal Building-Integrated Photovoltaic Applications - Kiss + Company Architects, 1996.
	Eiffert, P.: Building Integrated Photovoltaic Power Systems Guidelines for Economic Evaluation; Report T7-05 IEA PVPS Task 7, 2002.
	Potential for Building Integrated Photovoltaic; Report T7-04 IEA PVPS Task 7, 2002.
	Schoen, T.J.: Building-Integrated PV installations in The Netherlands: examples and operational experiences; IEA PVPS Task 7, Photovoltaic Power Systems in the Build Environment.
	Zondag, H., Bakker, M., van Helden, W. editors: PVT ROADMAP, A European guide for the development and market introduction of PV-Thermal technology; PV Catapult project, supported by the European Union under contract no. 502775 (SES6).

Web sites

	PVT Forum, PVT Forum has laid the foundations for a large-scale introduction of PVT technology in Europe, by bringing together PVT experts, PV and solar thermal industries and other stakeholders in a set of workshops, laying the basis for a new and strong European network for PVT technology.
	The International Building Performance Simulation Association, IPBSA is a non-profit international society of building performance simulation researchers, developers and practitioners, dedicated to improving the built environment.

Other

	Posbic, J.P.: Economic Optimization of Building Integrated Photovoltaic Systems; SOLAREX A Business Unit of BP Amoco/Enron Solar, 2001.
	Take a tour trough the Maine Solar House; design, solar energy use etc.
	Improving the world through passive solar homes, plans, and solar concepts, TheSolarPlan.com.
	Roofs available for PV installations in Germany, Alpensolar Dachbörse.