By Business India Editorial

Eyebrows will be raised if we say CO₂  can play a role in fighting global warming. But an Italian startup has found a way to turn carbon dioxide into a weapon to fight global warming. 

Energy Dome launched its first CO₂ battery facility in Sardinia and entered the commercial scaling phase. 

The emission-free storage method stores power generated from the sun and wind. CO₂ plays a useful role in the process as it has properties that can help to store electricity from renewable energy sources when it is converted from gas to liquid.

“The issue with renewable energy is that those sources of energy are very clean, but they are also intermittent and cannot be dispatched,” Energy Dome founder and CEO Claudio Spadacini said.

The storage technology could prove to be a game changer in the way solar and wind power are used, as they are variable energies that are only generated when there is sunshine or wind.

“The missing technology to make renewable energy dispatchable 24/7 is a technology which is able to store solar when the sun shines and when the wind blows and can deliver (energy) back to the grid when the sun doesn't shine.”

This method, which has never been used before, stores energy using pressure and heat. 

The process begins by storing CO₂ gas, secured from commercial vendors, in a big sealed dome. When energy is fed into the system, it pushes the gas through a compressor to condense it into liquid, while the heat from this compression is captured and stored to be used again later.

When it is time to discharge the energy, the heat that was stored is used to evaporate the liquid CO₂ again, and its expansion — as it turns into gas and returns to the dome — drives a turbine that generates energy.

Though it sounds complicated, the method only requires steel, CO₂ and water, and the closed-loop system generates no emissions.

“Ironically, we use CO₂ to make our system work. It is just the fuel which we use to make our technology work,” Spadacini said, adding that it’s only needed to kick-start the system, which is designed to last around 30 years.

“Our system is fully closed, we have no emissions in the atmosphere. It's just a black box which is able to charge with the surplus electricity when there is an abundance [of it]”.

“The CO₂ battery is fully sustainable and fully recyclable,” Spadacini said. “We just use steel to produce the CO₂ battery and we use water only once to fill our water tank. We do not use water during the operation of the CO₂ battery and we just use a small amount of CO₂ to charge the battery at the beginning without any consumption of CO₂ during the operation”.

The other advantage of this technology is that it does not rely on lithium-ion batteries, which are often used for energy storage. The process also does not use any rare earth minerals such as cobalt.

“To be independent of minerals and rare material is a big advantage also from the point of view of energy security, but also in terms of geopolitical stability,” said Spadacini.

The company is now getting ready to deploy its first full-scale plant by the end of next year.