Why the G7 calls for a six-fold increase in energy storage

Necessary

The battery, the basis of the growth of electric vehicles, is just as essential as that of wind turbines and solar power plants, which do not produce electricity 24 hours a day. If the world wants to deploy green energies as much as possible, it will have to have enough to store the surplus electricity produced when there is a lot of sun or wind: to inject current when the user needs it, during peaks of consumption, or in the evening, or when there is no wind... "It's the glue that holds the whole electrical system together", we summarize at the International Energy Agency (IEA) .

In 2023, according to the IEA, the deployment of batteries coupled with wind or solar fields, photovoltaic roofs or even mini-grids, grew at an unprecedented rate of 130% compared to 2022.

The main markets are China, then the European Union and the United States. Next come the United Kingdom, South Korea, Japan, but also developing regions including Africa where solar with storage is seen as a key to accessing energy.

However, global storage capacities will still have to be multiplied by six by 2030, calculated the IEA, if the world wants to triple renewables by this horizon, as it committed to at the UN conference. on climate COP28.

Objective: replace fossil fuels (coal, oil, gas) to keep warming below 1,5°C compared to the pre-industrial era.

The necessary storage capacity (batteries and others) by 2030 is estimated at 1.500 GW, including 1.200 GW by batteries.

Challenges

In less than 15 years, the cost of batteries has fallen by more than 90%.

“In India, the solar photovoltaic-battery combination is today competitive with new coal-fired power plants. In a few short years, this will be the case in China and with gas power plants in the United States,” argued the director of IEA, Fatih Birol, on April 25 during the publication of a special report.

“But this progress is not fast enough to allow us to meet our objectives in terms of climate and energy security,” he warned.

Costs will have to fall further, insisted the economist, who also calls for diversifying supply chains.

Most batteries are produced in China. Among the projects announced, however, 40% are in advanced economies, particularly the United States or Europe.

Another thorny subject is the resource of critical metals.

Experts, however, point to the future arrival of promising chemistries, notably sodium-ion accumulators, alongside current lithium-ion batteries. “Technological developments will reduce the quantity of lithium” needed, underlines Brent Wanner, head of electricity at the IEA, lithium, cobalt and nickel being “the key metals in batteries” today.

Get organized

Alongside batteries, other storage solutions are possible, but less available or quick to deploy.

Among them, "Step" type hydroelectric dams, some of which have existed for a long time, and which, equipped with a pumping-storage system, raise the water in a higher basin when electricity is abundant, for bring it down and generate electricity when it is lacking.

Another option: in the more or less near future, the transformation of electricity into hydrogen, which can be stored and transported.

Finally, renewables will not have to rely on storage alone. As is already somewhat the case, other so-called "flexibility" measures are added: interconnections (European for example), measures to "manage" demand (act on consumption hours, peak/off-peak hours ...)...

For all this, action will be required from industrialists but also from public authorities (international standards, incentives for metal recycling, etc.), all actors who are just beginning to organize themselves.