Fraunhofer Institute for Solar Energy Systems (ISE)

In November 2001, the Institute for Solar Energy Systems (ISE) opened its new premises in Freiburg, Germany. ISE, which is based in Europe’s so-called ‘Eco-Capital’, used the building as an example of what is possible with solar energy. Its own specialists were very much involved in integrating the architecture with solar technology.

The building comprises of 13000m² of floor space, two thirds of which is used for laboratories and the rest as offices. After the initial entrance block, the building divides into three specifically designed finger-like wings. The wings are oriented from East to West and are well spaced to allow daylight into the working areas. The offices are on the south side, to utilise the sunlight, whilst the laboratories are shaded on the north side. The entrance block provides some shading to the wings to prevent overheating in the summer afternoon sun.

Many measures are put in place to minimise energy consumption and increase human comfort. These include

• Optimised lighting controls, which involved the use of computer simulation in the design stage.
• Passive cooling by a combination of nocturnal ventilation, pre-cooling of inlet air in an earth-to-air heat exchanger, and solar control systems
• Thermal insulation optimising solar energy gains with glazing and ventilation.
• Heat recovery to reduce heat demand in winter.

A CHP plant, which is gas fuelled, supplies the main power source. This source supplies electricity together with heating and cooling. The cooling is implemented by reversing the heating process with an absorption chiller. Photovoltaics and solar collectors also provide heat and electricity and are integrated into both the architecture and the system for meeting the building’s demands.

As mentioned at the outset, the ISE premises has been used as an exemplary project, with its cost of 35 million Euros being funded by grants. However, the ISE is showing that solar energy could become a viable option for energy production, both economically and scientifically. There has been great growth in the sector. The ISE in fact receives over a third of its budget from money generated commercially. Set against the opposition to nuclear power and the ever-dwindling fossil fuel resources, solar energy is gaining more support, particularly in southern Germany’s sunny climate.