Solar modules and wind parks can now be found on roofs and meadows across the country. The alarm calls sound correspondingly loud every time the federal government changes the Renewable Energy Sources Act (EEG). One of the biggest points of contention this time around is the future of solar and wind power pioneers. The wind industry sees the effects of the corona pandemic endanger the continued operation of wind farms that are no longer subsidized because the demand for electricity and thus prices on the stock exchange have collapsed. For 18000 photovoltaic systems also end at the turn of the year the payments made in the first EEG from the year 2000 have been decided. Consumer advocates warn that some old modules are now becoming unprofitable because the Ministry of Economic Affairs wants to oblige even simple row house owners to install expensive measurement technology.

Future of private solar energy At the end of September the cabinet passed its draft of the new EEG. It illustrates the concern of the Ministry of Economic Affairs: the fear of uncontrolled feeding. The background lies in the rules of the electricity market. For every kilowatt hour that flows into or out of the grid, the so-called balancing group managers have to find a balance every quarter of an hour – otherwise the grid could collapse.

So far, electricity traders and grid operators have done this job. When the subsidy expires, the commercial acceptance of renewable electricity and thus the allocation to a balancing group ends. Because self-consumption is not recorded by measurement technology, the balancers estimate the amount of electricity of all private customers. However, you cannot predict when households will use how much of their own weather-dependent electricity for washing or vacuuming. So they supply these customers with electricity even when the sun is shining and the solar system owner actually has enough. This has three disadvantageous effects: Too much electricity in the grid endangers grid stability. The CO2 emissions increase because the additional electricity supplied comes to a large extent from fossil energy sources. And the costs also increase unnecessarily.

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