has met the requirements of a low energy design for an office building
in Austria which minimises solar heat gain, maximises the use of
natural daylight and allows the generation of electricity through the
application of photovoltaic technology.
Photovoltaic electricity generating cells are fixed
onto the louvre blades, with an area of some 250m▓ producing 15,900kWh
annually. This amounts to over 40% of the electricity required for the
At the same time as a
comfortable internal working environment has been provided, the
aesthetic appeal of the building has been enhanced.
Perhaps the most
innovative aspect of the design is the sun-tracking system which is
completely autonomous and powered by a Girasol thermohydraulic sun
tracking device. This device ensures that the louvres track the
movement of the sun during the day without the need for expensive or
complex electro-mechanical control systems.
There are 13 louvre sectors on each of the 4 floors.
For the Girasol device to operate effectively, each of the 52 different
sectors is linked to a solar absorber which calculates the position of
the sun. This, in turn, provides the correct positioning of the louvres
via a hydraulic system and actuators.
The project was supported by a EU Thermie grant, and
the system was the first of its kind to be installed on a building in