Some batteries can now import and export electricity directly from the grid and you could install a domestic battery without having any renewable generation. With a time-of-use tariff your battery can store cheaper electricity during off-peak hours (typically at night) to be used when electricity is more expensive.
The solution could hardly be simpler. The grid itself signals what it needs. When the frequency increases, more power is being pushed in than taken out, so additional power needs to be stored. When the frequency drops, the grid needs power, so the batteries push power back in.
When demand and prices climb, the company resells the electricity. It’s a classic play: Buy low, sell high. People in the automobile and energy industries have been talking for years about using car batteries for grid storage. As the number of electric cars on the road increases, those ideas are becoming more tangible.
Ford Motor, General Motors, BMW and other automakers are exploring how electric-car batteries could be used to store excess renewable energy to help utilities deal with fluctuations in supply and demand for power. Automakers would make money by serving as intermediaries between car owners and power suppliers.
For the midterm, battery storage will therefore primarily improve grid stability in Germany – at least to the extent that these storage systems are tailored to grid needs and not to the optimization of solar power consumption in households. Younicos is thus focusing on the market for ancillary grid services (frequency response), not arbitrage.
China is likely to be the main winner from the increased use of grid-scale battery energy storage. Chinese battery companies BYD, CATL and EVE Energy are the three largest producers of energy storage batteries, especially the cheaper LFP batteries.