13 years of pv in a crèche: A success story

13 years ago, on the initiative of the then mayor, a 25-kilowatt peak photovoltaic system was installed on the roof of the Rothenkirchen day-care centre. At that time, it was designed as a classic feed-in system that feeds its entire production into the public grid. With a feed-in tariff of around 40 cents, the system generates attractive income, which the municipality invests in the equipment and maintenance of the day-care centre. This year, for example, with the help of the PV profits and subsidies, additional playground equipment worth 12,000 euros was purchased for the outdoor area.

The subsidy for the day care centre's PV will expire in seven years. After that, the system is to be converted to self-consumption. In the future, an electricity storage system could be purchased to hold back the excess capacity of the day for the sunless morning hours of the following day. The 25 kilowatt peak of the system is easily enough to cover the annual electricity demand of the crèche and kindergarten.

The photovoltaic direct current is now converted into alternating current by three KOSTAL inverters, one for each orientation of the three roof surfaces, namely south, south-east and east. With this, the nursery PV is once again delivering full power - on average 22,000 to 23,000 kilowatt hours per year.

"The income from photovoltaics is a lot of money for a small community like ours. We are all the more pleased that we are now benefiting from the foresight of our former mayor and the municipal council," Beatrice Küttner comments on the Kita-PV initiative.

But the current mayor is also counting on renewable energies for the future. A photovoltaic system for self-consumption is to be installed on the school building as well. And if the electricity from the existing day-care centre PV should not be sufficient for the property after all, or if electricity consumption in neighbouring buildings is made easier by the legislator, the roof of the day-care centre offers space for additional PV modules.

The nursery extension surrounds the older building, which houses the kindergarten, on three sides (south, south-east, east). This means that the system, which consists of three parts distributed parallel to the roof, has an ideal orientation for self-consumption: the eastern part already supplies solar energy in the early morning. Then the south-east part takes over and finally the south side, which supplies power until late afternoon when the facility closes. "However, self-consumption is not an issue until the subsidies expire," says Dipl.-Ing. Beatrice Küttner.

The civil engineer is the property manager in charge in Steinberg and responsible for looking after the photovoltaic system. "The former mayor who initiated the plant in 2010 was a master electrician and chairman of the electrical guild. He already had a lot of experience with photovoltaic systems back then and has really done the community good with the system," says Küttner. The technically trained eye can see at first glance that not only the available space has been optimally used, but also that all distances to the roof edge are correct.