The photovoltaic system on the roof of the Wieselburg campus (district of Scheibbs) supplies 70 megawatts per year. This corresponds to a third of the annual electricity requirement, but only ten percent of the solar power is used by the user. This is partly due to the holiday season and the weekends, says Josef Walch, who is responsible for sustainability at the Wieselburg campus. “We have a significant surplus there. We then sell this on the energy market.”
In the planned renewable energy community, the excess electricity is no longer fed into the general grid, but used by other members of the community. Before starting, however, an energy community must be well planned, for example there must be a sufficient ratio of pure consumers and prosumers – these are members who also generate energy themselves – more on this in How Energy Community works in practice (noe.ORF.at; 20.5.2022).
Ecological neighborhood help: “Exchange electricity
Since the prices for electricity and gas have exploded, saving energy has been the order of the day. So-called energy communities offer an attractive option. Excess energy, from photovoltaics for example, is simply passed on to the neighbors.
This planning is carried out at the University of Applied Sciences by researchers in the “Renewable Energy Systems” course. The aim is to use the electricity generated by the community in the community. Philip Loitsch from the Institute for Sustainability on Campus describes this as “intelligent planning”: “Which consumers do you add, which households or is it better with companies because the load profile is better there,” Loitsch counts in an interview with ORF editor Robert Pfannhauser some questions.
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Using surplus electricity intelligently
In the future, software developed in Wieselburg will provide answers to these questions. “This tool is designed to help create energy communities so that we can predict how useful the community is,” says Walch. It’s regarding the so-called self-consumption rate, which can be improved with digital interfaces. These have direct access to data from the power generators and consumers.
Die self-consumption rate indicates what percentage of the self-generated electricity is used to cover your own electricity needs.
The measured data on consumption and feed-in come in real time via these interfaces. “And we can also switch generators and consumers,” explains Walch. At lunchtime, when the PV system on the Wieselburg campus produces the most electricity, the consumption of the energy community members might then be adjusted accordingly.
“You might then talk to the sewage treatment plant operators, for example, whether they don’t want to use the excess electricity exactly when the energy is there – i.e. maybe not flush the pumps at 10 a.m., but at midday,” says Loitsch.
The price for the self-generated electricity within the community is determined by the producers themselves. The community also relieves the national electricity grid, says Walch: “Because electricity that is generated regionally is used regionally.” The Wieselburg energy community is scheduled to start in early 2023.
