Building-integrated photovoltaic

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The CIS Tower, Manchester, England, was clad in PV panels at a cost of £5.5 million. It started feeding electricity to the national grid in November 2005.

Main article: Zero-energy building

Building-integrated photovoltaics (BIPV) are photovoltaic materials that are used to replace conventional building materials in parts of the building envelope such as the roof, skylights, or facades. ^[1] They are increasingly being incorporated into the construction of new buildings as a principal or ancillary source of electrical power, although existing buildings may be retrofitted with BIPV modules as well.^[2] The advantage of integrated photovoltaics over more common non-integrated systems is that the initial cost can be offset by reducing the amount spent on building materials and labor that would normally be used to construct the part of the building that the BIPV modules replace. In addition, since BIPV are an integral part of the design, they generally blend in better and are more aesthetically appealing than other solar options. These advantages make BIPV one of the fastest growing segments of the photovoltaic industry.^[3]

Roof tiles and roof membranes with integrated PV cells can now be purchased. With the exception of Japan, where a combination of government incentives for PV and a high proportion of new houses being prefabricated allowed BIPV to be a part of a substantial number of new homes, substantial progress of BIPV has been restricted by the relatively high cost or limited availability of BIPV modules. The French government put in place a large subsidy for BIPV modules vs. standard modules in 2006. This is expected to stimulate BIPV installations in preference to standard modules.

1 Costs and incentives
2 Roofs, facades and windows
3 See also
4 References
5 External links

[edit] Costs and incentives

See also: PV financial incentives

In some countries, additional incentives are offered compared to stand alone PV. Only in France is the premium enough to make a substantial difference.^{[citation needed]}

France + EUR 0.25/kWh
Italy + EUR 0.04-0.09 kWh
Germany + EUR 0.05/kWh (facades only)
USA - Varies by state check Database of State Incentive for Renewable & Efficiency http://www.dsireusa.org/

[edit] Roofs, facades and windows

Photovoltaic solar panels on a house roof.

BIPV modules come in several forms.

Flat roofs
- The most widely installed to date is a thin film cell integrated to a flexible polymer roofing membrane (Sika, Alwitra).

Pitched roofs
- Modules shaped like a multiple of roof tiles, including Solar Century (.uk) Marley, Imerys, BP Solar, Powerlight (CA)
- Solar shingles are modules shaped like shingles, incorporating a flexible thin film cell

Facades
- Special building elements designed to receive modules are also available e.g. a sandwich element composed of two metallic corrugated and ribbing sheets and, inside, of high-density polyurethane foam. The panel has a profile specifically designed to insert a custom-made photovoltaic module, considering the indispensable ventilation requirement on the rear surface of the module. Through the interstice an optimal level of working temperature is ensured for the system and the different thermal expansions are respected.

Glazing -transparent modules based on architectural glass elements
- with crystalline silicon cells (in the UK from Romag)
- with very thin amorphous silicon (Schott Solar 'Asithru', XsunX)