How to calibrate electricity storage needs for the future? The necessary capacities seem important, but we are still far from it. A study shows that we must carefully gauge the technological solutions that will really have an economic value in 2030 and then 2050.
The new energy system needed to the transition is gradually being put in place, in particular for the production of electricity where renewable sources (mainly wind and solar photovoltaic) will be essential, as several scenarios show (TEN, Ademe, negaWatt). If France had not taken lag in this areait would also have less difficulty in spend the winter. It is therefore likely, as the bill on renewable energies currently under consideration should allow, that their development will be accelerated.
The variability of these electrical renewable energies ultimately raises the question of the electricity storage. In addition to the traditional pumped energy transfer stations (Step), a sector for stationary batteries has begun to emerge a few years ago. Worldwide, 16 GW of these batteries were installed at the end of 2021, including 6 GW that year. According to the International Energy Agencythe transition to an energy system reaching carbon neutrality (Net Zero Scenario) would require reaching 680 GW of batteries in 2030, i.e. the installation of 80 GW per year on average from 2022!
At the European level, the will displayed is to keep control of this technological brick of batteries, in order to be independent of other countries-continents such as China (which has the largest manufacturers of Lithium-ion batteries) and the United States. States (which concentrate the largest number of projects in the world). But no specific framework is given to the storage of electricity at community level. It is mentioned in the Clean Energy Package, but with no specific purpose. The promoters of this solution, grouped within the European Association for Energy Storage, have nevertheless clearly quantified the need: according to them, with regard to the tripling of wind and solar capacities necessary for the EU’s 2030 renewable energy objectives, it should deploy 200 GW of storage in 2030 and grow to 600 GW in 2050. To keep up with this rate of 14 GW new each year, the economic valuation of stored electricity must be facilitated in relation to the current rules of “market design”.
Value of storage in France in 2030 and 2050
Defining electricity storage needs in fact requires having a global vision of the energy system, the different vectors and the different possible transformations. A recent study by the company Artelys for the Storage Club of the Association Technique Energie Environnement (ATEE) tries to clarify what the future would be by including precisely electrical storage, either direct (batteries, Step), or by a thermal solution, or by the transformation of electricity into hydrogen then possibly other molecules (power to gas) in France by 2030 and 2050. All the costs of these storage solutions are falling and it is important to know in which situations they will be of most interest for the community. Artelys’ analysis therefore determines what is the value of adding an additional storage facility compared to scenarios that already present a certain mix, in this case those of the three RTE scenarios M1, M23 and N2, the first being the one that uses storage the most (20 GW of batteries and more than 15 GW of power-to-gas in 2050).
The study, called PEPS5 (not yet published, but which was presented at an ATEE symposium in early October), raises 15 case studies, half of which relate to direct electricity storage. If we only consider the latter, we can retain three key messages.
- In the case of centralized storage in Metropolitan France, in particular for batteries, the supply of primary and secondary reserve on the electrical network has no real economic interest due to strong competition on this market. The addition of step (compared to RTE’s scenarios) is economically relevant, whereas for batteries it is necessary that gas prices remain high. On the other hand, all the storage solutions make it possible to reduce CO emissions2 by 2030.
- In a decentralized manner in individuals or at the scale of a community, storage to maximize self-consumption of electricity (without reinjection into the network) serves the people concerned, but has no economic interest from the point of view of community view. On the contrary, the control of the charge of electric vehicles is economically interesting for the community. Tariff steering (less optimized, but easier to implement) is more relevant than dynamic steering (where the load profile is optimized with an hourly price signal) which itself is more relevant than vehicle-to-grid (the vehicle can restore electricity to the network).
- In island areas (not interconnected to other networks), storage is all the more important as the development of renewable electricity will increase sharply, particularly in solar photovoltaic. In this case, centralized storage is very relevant.
Overall, this study shows that beyond the RTE scenarios where a certain balance has already been found with a share of storage, the addition of additional capacity will have to be carefully studied. But until then, the legal, regulatory and pricing framework for storage still needs to be improved so that it begins to develop seriously.