Households replace power plants – sonnen is commissioning the largest, virtual battery for the electricity grid of the future

For the first time, sonnen is supplying reserve power to the German energy market using networked battery storage systems. This creates the largest virtual battery currently in operation which can compensate for fluctuations in the power grid. Households are thus able to take on all the tasks of conventional power plants. 

sonnen, together with its technology partner tiko Energy Solutions, has received the pre-qualification from the transmission system operator TenneT for the provision of primary control power for its Germany-wide network of home battery storage.

Thus, sonnen provides the energy market with the largest virtual battery available today, consisting exclusively of individual home storage systems. This can be used, for example, to compensate for fluctuations in the power grid. In addition to supplying its customers with clean and decentralized electricity, sonnen can now also provide flexibility for the energy markets, expanding its offer as an energy provider of the future.

“We are very happy that as a young company we are writing energy history. This shows that our customers can take on all the functions previously reserved for large power plants. They can generate and store energy and ensure the security of supply in the power grid. The change from the old energy system with central power plants to the new energy system with the human being in the center, thus becomes final “, says Jean-Baptiste Cornefert, managing director of sonnen eServices.

The virtual battery from sonnen works on a unique approach. It consists of thousands of individual electricity storage facilities throughout the country that are used for their own households’ own consumption. If there are fluctuations in the power grid, these batteries arrange themselves automatically by artificial intelligence to create a large virtual battery. Since every solar battery has a different state of charge, the large number of individual battery services is combined in a block from 1 MW and made available to the energy market. TenneT’s purchase of the virtual battery meant they had to disconnect and re-power 1 megawatt of power within 30 seconds. With the test successfully completed, the virtual battery has qualified for participation in the so-called primary control energy market.

With this power, for example, short-term fluctuations in the power grid can be compensated within a very short time. If there are deviations in the mains frequency of 50 Hz, the memories can automatically absorb or release energy from the network in a matter of seconds – depending on what is needed. So far, mainly CO2-intensive power plants are used for this primary control power. sonnen’s networked home storage helps to take these power plants off the grid faster.

“We are proud that we have been able to implement our virtual power plant technology with sonnen. For the German market, this is a pioneering work, so battery storage can provide the dual benefits of self-consumption and various services in the energy market. With sonnen, we were able to show, among other things, that primary control power can also be supplied with home battery storage in Germany, “says Fréderic Gastaldo, CEO of tiko Energy Solutions.

“The ability of networked battery storage as a virtual power plant to stabilize the grid in the event of frequency fluctuations is another step on the way to greater system integration of renewable energy,” said Lex Hartman, CEO of TenneT. “System services that stabilize power supply have so far been provided mainly by conventional power plants, and as renewables become more widely used in power generation, they need to be more accountable,” says Hartman.

Prequalification for the primary control power market is subject to the strictest requirements of technology and safety in the energy market. As sonnen has now received the highest certification, its network of home battery storage is also predestined for further services in the electricity grid. In contrast to stationary large storage facilities or power plants, sonnen’s decentralized battery pool can be used flexibly in almost every location in Germany.

Customers benefit from the energy market

With the sonnenFlat, sonnen offers a specially developed electricity tariff that enables storage owners to benefit from the network services. In exchange for the provided capacity, they receive a free flow. The use of renewable energy is even more profitable for solar battery owners.

sonnen has about 30,000 solar batteries in Europe, which together have a capacity of up to 300 MWh. This creates the potential to power around 120,000 households for one hour. The size of the individual solar batteries is between 5 and 15 kWh.