Energy storage power station investment income

While energy storage is already being deployed to support grids across major power markets, new McKinsey analysis suggests investors often underestimate the value of energy storage in their business cases.

Evaluating potential revenue streams from flexible assets, such as energy storage systems, is not simple. Investors need to consider the various value pools available to a storage asset, including wholesale, grid services, and capacity markets, as well as the inherent volatility of the prices of each (see sidebar, “Glossary”).

The return of investment is an important metric about how attractive an investment may be. However this is an important note that energy storage usually does not generate electricity savings directly, but allows the transport or trading of electricity. This usually results in storage not having a high ROI like solar investments, for example.

The storage NPV in terms of kWh has to factor in degradation, round-trip efficiency, lifetime, and all the non-ideal factors of the battery. The combination of these factors is simply the storage discount rate. The financial NPV in financial terms has to include the storage NPV, inflation, rising energy prices, and cost of debt.

Such complexity means the expected economic returns are often undervalued, especially if shortcuts are taken to simplify the analysis. Adopting a holistic approach that considers all revenue streams across a broad range of external events could improve the outlook of energy storage returns.

Ancillary services that stabilize the power grid typically represent 50 to 80 percent of the full storage revenue stack of energy storage assets deployed today. This is observed across multiple mature storage markets but is expected to decrease to less than 40 percent by 2030.