Electricity storage manufacturer Sonnen will connect 2000 battery systems to create a storage plant which can be used to deliver control power. The earnings from participating in the control power market allow free-of-charge power delivery to owners of the batteries.

Sonnen battery (Foto: sonnen GmbH)
© sonnen GmbH

The connection of 2000 batteries as a virtual battery could allow the German company to participate on the primary control market. This also means that battery systems used for PV units on private households could be used to stabilize the power network. Due to the fact that primary control is only demanded for a very short amount of time, only a small amount of the capacity of the batteries is used. During one day the batteries only have to deliver primary control power for several minutes, which means that the owner doesn’t even notice the battery usage.

The profit for the customers is as such: As an owner of a battery from Sonnen and a PV unit about 75 percent of a household’s electricity demand can be covered by their own production. If a customer then decides to take part in the control power pool with his battery, the remaining 25 percent of the electricity will be delivered free-of-charge by Sonnen. “The customer saves about 200 to 250 euros a year” says Phillip Schröder, managing director of Sonnen.

In Switzerland the company Sonnen is already using a pool of 6500 heat pumps and night storage heating units to deliver primary control power to the Swiss grid. In June the network provider Swissgrid certified and accepted the system created out of the 6500 units, so that the system as a whole is now officially a qualified provider of primary control power.

The benefit for the energy economy would be that less capacity in fossil fuel power stations would have to be held back for primary control power. This would therefore reduce costs and environmental impacts. Sonnen expects to be granted permission from the German Transmission System Operators in the first quarter of 2017. This would mean that this free-of-charge electricity flat-rate could also be availble in Germany fairly soon.