PV projects

'Photovoltaics in Architecture'

based on: Photovoltaics in Architecture in the Netherlands, ir. Tjerk Reijenga M.Sc., Progress in Photovoltaics, Vol. 4, October, 1996

Summary

The Netherlands has a program for the integration of PV modules in the building envelope. The aim of this program is to realise 250 MWp in PV-systems in the year 2010. Within this program the integration of PV modules in architecture has an important role. Here are the opportunities for architects. New technology and materials are an invitation for a new design.
BEAR Architecten is involved in several low energy, bio-climatic building projects, amongst them, a few PV projects:
· De Kleine Aarde, an Environmental Education Centre with PV panels in the roof.
· Roof retrofit with PV modules in 5 houses in Leiden.
· Facade integration with PV in 22 houses in Dordrecht.
· Roof integration in a utility building in Geldermalsen.
- Roof and facade integration (700 m2)of an laboratory building.
Information about these projects is given. But also the possibilities and the problems will be discussed here. A general conclusion is that custom made modules are often necessary to make well designed buildings.

The Netherlands has a history in the use of sustainable energy. Since long ago windmills are used for all kinds of purposes. With the introduction of fossil energy supplies, the role of wind energy decreased. In the last 15 years there is a new and increasing interest in sustainable energy. The Dutch government has several R&D programmes on energy. One of these research programmes is the National Photovoltaic Programme. In the context of this programme, the Netherlands Agency for Energy and the Environment (NOVEM) encourages activities directed at achieving future large scale applications of photovoltaic solar energy. NOVEM also initiates activities such as demonstration projects involving grid-connected systems for the urban environment.
The aim of these activities is to achieve savings of 2 PJ on fossil fuels by the year 2010. This means, based on the technology of today, approx. 3.000.000 m2 of PV modules or 250 MWp has to be placed. Within this programme the integration of PV modules in architecture has an important role as well in new buildings as in existing buildings.
The possibilities for building integrated photovoltaics (BIPV) are better in the Netherlands than in other European countries. The Housing Law (1901) together with land politics has given the Dutch government instruments to regulate building. Because of the regulation there is a history in building (social) housing in projects. The central government plans the locations for new housing layouts. For the next 15 years plans are being made for approximately 800,000 houses.

To make PV-systems more accepted, attention is given to the architectural aspects of building integrated photovoltaics. The architectural aspects is also one of the issues of the European Thermie programme.
BEAR Architects is involved in several low energy, bio-climatic building projects, amongst them, are several PV projects:
· De Kleine Aarde in Boxtel (NL) (Thermie project SE104/93/NL).
· Roof retrofit with 11.5 kWp PV modules in 5 houses in Leiden (NL).
· Facade integration in 22 houses in Dordrecht (Thermie project SE102/95/NL).
· Roof and facade integration with 114 kWp in two office buildings in The Hague.
· Roof integration with 4.2 kWp in a utility building in Geldermalsen.
. Retrofit with 70 kWp photo-voltaic shading system ECN Petten (Thermie project SE100/97/NL/DK)
. Roof integration with PV for 56 wall houses in Amersfoort.

Future Improvements
An important issue for improvement are the dimensions of the PV modules. The dimensions of PV panels are not based on (measurement) agreements in the building industry. This sometimes causes problems, especially in existing buildings. A broader range of dimensions is recommended. In the latest projects, custom-made modules are used. This improves the possibility for architectural integration of photovoltaics.

Colour

To make a roof with PV modules, we have to combine several materials. Each material with its own texture and colour. Many choices in the colour of modules and profiles are needed to make good-looking combinations. Architects are, on the whole, very enthusiastic about the use of the blue or black polycrystalline colour in a building design.

Integration

A traditional roof in The Netherlands is covered with concrete or clay tiles. PV modules have a different texture, which does not combine with the common type of tiles. Many different elements like windows, solar collectors, chimneys and PV modules in a roof make it very difficult to design a good-looking roof. Integration among these elements is necessary to make the roof acceptable to the eye.

Guarantees

Guarantees on building constructions with photovoltaics are needed. To enlarge the scale of BIPV, the modules must be applied in the same way as other building materials. For the average architect, PV modules are just pieces of colourful glass.

Possibilities for the near future.

The main limitation for photovoltaics in housing projects at this time is the price. In office or public buildings, it is more common to use expensive building materials. For this reason, there are more opportunities to introduce PV systems in this sector.
Transparent laminates can be used as a good alternative for shading devices, and the double function makes the application less expensive. Possibilities include office and public buildings and shopping centres.

Literature

  • Drs. W.O.J. Böttger, drs. L.E. de Graaf, drs. M. van Schalkwijk, ir. A.J.N. Schoen, ir. T.H. Reijenga, ir. P. Blesgraaf, Voorstudie integratie PV-modules in vliesgevels, grote glasoverkapte ruimten en zonweringen (Preliminary study PV-modules in glassroofs and -facades), Ecofys E 263 - NOVEM, Utrecht, 1996.
  • Ir. A.J.N. Schoen, drs. T.C.J. van der Weiden, ir. T.H. Reijenga, H. Lieverse, Integratie van PV in de gebouwde omgeving (Integration of PV in the build environment), Ecofys E 232 - NOVEM, Utrecht, 1992.
  • Ir. A.J.N. Schoen, drs. L.E. de Graaf, ir. T.H. Reijenga, H.P.W. Fransen, Inventarisatie profielen voor de integratie van PV in hellende daken (Profiles for the integration of PV in roofs), Ecofys E 276 - NOVEM, Utrecht, 1995.
  • Drs. W.O.J. Böttger, ing. K.J. Hoekstra, ir. A.J.N. Schoen, Ontwikkeling technisch programma van eisen voor een kwalitatief hoogwaardig en financieel aantrekkelijk PV-system Case study De Kleine Aarde (Concept) (Developing a brief for PV-systems. Case study De Kleine Aarde), Ecofys E 287 - NOVEM, Utrecht, 1996.
  • Ir. T.H. Reijenga, 'Leiden, renovatie van daken met PV-modulen', Met de zon de markt op, Vijfde Nederlandse Zonne-energie conferentie, Veldhoven 1995.
  • Ir. T.H. Reijenga, 'PV op woningen in Leiden', Duurzame Energie, 2, april 1993.
  • Ir. T.H. Reijenga, 'Renovatie van daken met PV-modulen woningen aan de Zonnewende te Leiden', BEAR Architecten - NOVEM, Gouda, 1994.
  • Ir. T.H. Reijenga, 'Photovoltaics in Architecture in the Netherlands - An architects view', Progress in Photovoltaics, Vol.4, October, 1996.

 

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