California: Successful energy transition thanks to battery storage
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California: Successful energy transition thanks to battery storage

GESI_Solar

The world’s fourth-largest economy now has a large-scale battery storage capacity of almost 16 gigawatts.

Pullach, 11.07. 2025 | Seven years ago, California was still something of a storage desert: the cumulative large-scale battery capacity amounted to just 0.5 gigawatts in 2018. But since then, the US state, which in itself would be the fourth largest economy in the world, has made rapid progress. According to market analyses, total capacity already amounted to 15.7 gigawatts in the spring – and the trend is continuing to rise sharply.

Battery storage systems are therefore now making a key contribution to the energy transition and stabilizing the Californian electricity grid. This was particularly impressive this week (see graphic from the German Association of the New Energy Economy): On July 7, large Battery Energy Storage Systems (BESS) began absorbing surplus solar power in the early hours of the morning – and released it back to the grid from around 6 p.m. local time until the storage units were empty around midnight (see the purple-colored, hill-like areas).

Thanks to the storage systems, neither solar parks nor wind turbines had to be throttled back or even switched off. In addition, cheaper green electricity was also available in the evening, which had a dampening effect on electricity prices.

As some might argue that the sun shines much more often in California and that the situation is therefore not comparable: yes, it is. In Germany too, large-scale batteries can stabilize the grid, lower the price of electricity and also ensure a significant reduction in greenhouse gas emissions.

It is therefore high time to stop discussing highly subsidized gas-fired power plants – and to focus more on how we can quickly connect privately financed, efficient large-scale batteries to the grid. To achieve this, we need faster planning and approval procedures, fair rules on construction cost subsidies and planning security with regard to grid fees California has shown what is possible in seven years. Can we manage that too?

Further contributions

Following the conclusion of the energy transition monitoring, the German government is planning reforms. We have summarized what is important here in a position paper. The common goal of the storage industry and politicians must now be to establish large-scale batteries as part of the solution for an affordable and sustainable energy transition. To achieve this, a reliable framework for investment must be created. You can find out which new...

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