If we want to reduce the use of fossil fuels on the planet, we will have to bet on electricity produced by renewable sources. They have a problem: they have to install a lot of generation capacity, since sometimes there is no sun, or the wind does not blow enough, or the water is needed for other purposes.
The solution is to store energy when it is produced in order to use it when it is needed. And that they have done in China, where the world’s largest flow battery connected to the network has been operating since September 29.
Installed in the city of Dalian, it is the largest storage system in the world. It has an initial capacity of 400 MWh and a production of 100 MW and will supply energy to 200,000 inhabitants every day. It will be a kind of energy bank for the city and will help consume renewable energy sources.
It is a vanadium flow battery, so this energy storage system differs from lithium-ion batteries used in electric cars or smartphones. In huge tanks, chemical energy is stored in the form of liquid electrolytes, which can be converted into electricity by passing the fluid through a special membrane.
That’s where their name flow batteries come from, which looks set to be a relatively cheap and attractive energy storage solution, as they can store energy for months. This lends itself well to wind or solar renewable energy storage, which is intermittent in nature. It would also help cities to deal with spikes in demand of energy.
It is not the first in the world, since in Jemgum, in northwestern Germany, there is already a flow battery built in underground salt caverns that supplies enough daily energy for 75,000 homes. Dalian’s is larger and is designed to be expanded to produce 200 MW with a capacity of 800 MWh. For China’s first large-scale chemical energy storage demonstration project, it’s not bad at all.
Renewable energy sources will charge the batteries during the off-peak period, converting electrical energy into chemical energy. This will be converted back into electrical power for consumers once again during periods of peak grid load. In addition, it will help the Asian country to reduce its carbon emissions.
Source: Chinese Academy of Sciences
