Energy
What a battery earns in Germany
A battery on a site is not one business. Several revenues can be earned on the same cells, and they compete for the same hours. Which of them you intend to chase changes the size of the connection you apply for – which makes it an engineering decision wearing commercial clothes.
Storage is not one business. Four revenues stack on the same cells, and which of them you chase changes the connection you apply for.
Four revenues on one asset
Frequency products pay for standing ready to respond in seconds. Balancing products pay for energy delivered on instruction. Wholesale arbitrage pays the spread between cheap and expensive hours. And behind the meter, peak shaving avoids the network charges a site's own highest quarter-hour would otherwise set. The first three are markets. The fourth is a cost you do not incur, which is often the most dependable of the four.
They do not stack for free
An hour spent holding capacity for frequency response is an hour not spent arbitraging. A battery held at half charge to answer in both directions is a battery not full when the evening price arrives. Stacking is real and it is how modern assets are financed, but the stack is a scheduling problem with an opportunity cost, not four incomes added together.
Why this decides the connection
Peak shaving for a data centre needs power on site and little else. Marketing into wholesale and balancing needs the ability to export, which is a different connection, a different application and a different charge. If that decision is not taken before the grid application, the application is a guess. This is the single item most likely to be settled late and to cost the most when it is.
What we publish
This site states installed storage capacity and installed power as separate measured figures, because they answer different questions: how long, and how hard. It publishes no business case, because the operating mode is the owner's decision and the numbers move with it.
Sources
- 01Bundesnetzagentur – SMARD market data, balancing and wholesale
- 02⚠️ Revenue figures are market-dependent and dated the moment they are written. No case is published here.
