Study: the Energiewende does not need to wait for storage

The development of wind and solar systems in Germany during the next 20 years does not require new power storage. The flexibility needed to compensate for weather-dependent power generation can be provided much more cost effectively.

This can be achieved, for example, by the flexible operation of fossil power plants, demand side management in industry as well as power trading with neighbouring countries. Markets for storage technologies, however, will develop strongly in other sectors in the coming years - especially in transport and the chemical industry. The power system will be able to benefit from this. For example, as an additional benefit, batteries for electric cars can provide the electricity sector with added flexibility. These are the main results of the study "Electricity Storage in the German Energy Transition" conducted by four renowned research institutes on behalf of Agora Energiewende.

"The energy transition must not wait for storage. For the next 15 to 20 years - that is, up to 60 percent of renewable energies - we will have plenty of other, cheaper flexibility options available", says Patrick Graichen, director of the think tank supported by the Mercator Foundation and the European Climate Foundation. "The markets for new storage technologies such as batteries, power-to-heat or power-to-gas are nevertheless likely to grow dynamically due to an increasing demand in transportation, heating and chemistry".

The study distinguishes between long-term and short-term storage technologies and uses three scenarios to examine different types of storage expansion. These scenarios reflect the foreseeable power system of Germany in 2023 and 2033, as well as the  power system with a 90 percent share of renewable energies. In addition to using storage systems to compensate for variable power generation and demand, the study also considered their use for ancillary services.

Moreover, the use of storage systems to defer grid expansion at distribution grid level was also examined closely. It was found that battery storage can already today be used cost-effectively in some applications. These niche applications will, however, only reach a limited market volume in the long-term. "New power storage is currently still expensive. However, this can also change quickly. Storage must now already receive equal access to the markets. This applies to markets for flexibility, such as the current ancillary services market or a future capacity market. This also applies to the distribution network, where storage systems can be a tool in the toolbox of distribution grid operators", says Graichen.

The study was conducted by a consortium consisting of Fenes (OTH Regensburg), IAEW (RWTH Aachen), ef.Ruhr (TU Dortmund) and ISEA (RWTH Aachen) commissioned by Agora Energiewende.