The system was planned and constructed during the first half of 2003. The system has been operating since September 2003. In autumn, 2003, comprehensive measurement equipment with automatic daily data transfer to Fraunhofer ISE was installed.

The most important measurement data are also presented in parallel to visitors on site with a graphical presentation. The complete data acquisition system commenced operation on 1st December, 2003.

Figure 5 illustrates how the fuel cell fills the gaps in the power supply when the wind is weak and there is no solar radiation. Wind and sun complemented each other very well on this day.

3. Outlook

As well as modernising the power supply for the "Rappenecker Hof", another goal of this project is to use and demonstrate fuel cells in off-grid systems. It is important that fuel cells are applied in real systems under field test conditions now, in order to provide valuable information for their further development. In addition, it is intended to demonstrate the technology in the system to the general public. An innovative battery system is a further technological highlight of the new hybrid power supply.

The system consists entirely of commercially available components, with the aim of determining the extent to which the market can already provide the technology needed. The two-year test phase will concentrate on systems-technological optimisation of the individual system components. The comprehensive measurement technology installed ensures that particular questions can also be studied in detail.

Modernisation of the power supply for the "Rappenecker Hof" was possible as a result of funding from the innovation fund for atmospheric and water conservation of the utility, badenova AG & Co. KG in Freiburg. The project partners, the Riesterer family from Oberried, Phocos AG-Deutschland from Illerkirchberg and the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg also contributed with substantial sums toward the financing of this project.