May 22, 2024
This giant dome battery cuts CO2 emissions — by using more CO2

Renewable energies like wind and solar are clean, abundant, and cheap — but notoriously unpredictable. That’s why so much time and money has been pumped into scaling energy storage solutions: we need to keep the lights on even when the wind isn’t blowing or the sun isn’t shining.

While lithium-ion batteries have received the bulk of this investment, there’s another kid on the block that could be cheaper and greener. In an ironic twist, the whole system is powered by the same molecule it is attended to fight — carbon dioxide. 

Imaginatively, it is called the CO2 battery. The way it works is relatively simple. CO2 gets stored in a gigantic dome. When charging, the system pulls the gas from the dome, compresses it into a liquid and stores it in big carbon steel tanks. The compression process also produces heat which is stored in ‘bricks’ made of steel shot and quartzite for later use.  

Then, when power is needed, the liquid carbon dioxide is heated up using the hot bricks, rapidly turning it back into a gas — which refills the dome. On its way back to the dome, however, the gas spins a turbine, producing electricity.

an image of Energy Dome's pilot plant in Sardinia, Italy