Sharp rise in battery storage capacity

As the ecological transition moves forward, there has been a boom in energy storage in general, and electrochemical battery cells in particular. The goal of developing this technology is to:

  • Contribute to security of supply (via capacity mechanisms and primary frequency control);
  • Increase the rate of self-consumption by storing surplus energy for later use;
  • Make supply more reliable by optimising the management of local constraints, thus reducing the risk of micro outages…

Electricity storage systems make it possible to withdraw a specific quantity of energy from the network and store it before later releasing it back into the grid at the connection point. Storage solutions can be:

  • Mechanical: STEP pumped storage stations, Compressed Air Energy Storage (CAES), electrochemical (batteries, etc.);
  • Chemical (fuel cell, etc.);
  • Electrostatic;
  • Electromagnetic.

Within the scope of RTE’s businesses, the storage capacity in use today is associated with hydropower, whereas for ENEDIS, most is battery-based.
In 2020, total storage capacity reached 4,850 MW of which 4,810 MW was hydropower-based and 40 MW battery-based. These levels were unchanged from the previous year.

Closer look

Better understanding

Potential storage solutions via hydrogen production

The 2050 scenarios based exclusively or to a very large extent on renewable energies will necessarily have to rely heavily on storage. In these scenarios, the power-to-gas-to-power loop, via hydrogen, is an option to consider. Since electrolysers can adjust their electricity consumption in just a few seconds, it is technically possible for them to provide services both for balancing supply and demand and for grid operations.
However, energy efficiency is low (currently between 25% and 35% with today’s technologies). The potential long-term benefits of these solutions will be the subject of an in-depth study, along with an analysis of scenarios involving changes in the energy mix, as part of work on the Energy Futures 2050 study to be published in the autumn of 2021.