Unrestricted small-scale solar power feed-in threatens German grid stability – energy industry

Grid operators and energy industry representatives in Germany are calling on political leaders to approve immediate measures to better control small solar installations following the record expansion of photovoltaic (PV) systems in the country, Neue Osnabrücker Zeitung reported. Grid operator TenneT and the German Association of Energy and Water Industries (BDEW) are pushing political leaders to pass the necessary legislation ahead of Germany’s federal elections on 23 February, saying solar power peaks could threaten grid stability as early as this Easter.

Lawmakers will discuss a draft law on the controllability of solar systems this week, which could be approved by parliament before a new government takes power. "In order to integrate the growing share of renewable energy sources into the energy system efficiently and in an economically sensible manner, it is essential that the amendment to avoid peaks in production is implemented before the end of the legislative period," TenneT Germany CEO Tim Meyerjürgens told the newspaper. He added that this was an "important condition in order to keep the energy transition on track and at the same time ensure network stability and economic efficiency".

BDEW head Kerstin Andreae likewise warned that there was “now a threat to the stability of the networks without adequate control". Particularly during sunny days, problems can arise when too much electricity is generated at times of low demand. "Peak feed-in times pose increasingly significant risks to grid stability – and this is regardless of future grid expansion," Andreae explained.

Without the ability to specifically control generation in critical situations, there is a risk that individual grid lines will have to be temporarily disconnected from the grid in order to stabilise the system, so-called brownouts, she added. In order to maintain system stability, it is "urgently necessary that the measures contained in the draft law are implemented before the federal election", Andreae said.

Solar power is experiencing a boom in Germany. However, a large part of the newly installed capacity comes from small-scale systems of under 100 kilowatt each, which under current rules feed into the grid whatever they produce without the option to curtail production remotely when this is necessary to ensure grid stability.