Transforms CO2 into energy

US scientists have proposed a way to convert CO2 into huge "batteries" that store excess energy underground, address waste and reduce emissions.

Energy Batteries are made of CO2

According to a team at Lawrence Livermore National Laboratory in California, excess energy is stored in CO2 "batteries" in both pressure and heat.

CO2 emissions act as a greenhouse gas. (Image: Gizmag)

Excess energy is used to run a pump, putting CO2 in the supercritical state (liquid-gas state) into saltwater stores located in deep sedimentary rock about 1-5 km underground. When there is CO2, seawater will be pushed to the ground. Excess energy is then used to heat seawater and circulate it to deep rock layers, where heat is stored efficiently.

Sea water heated when exposed to CO2 expands, increasing the pressure on stored CO2. By lowering the CO2 emissions of turbines, the team says it is possible to save up to 50% more power than the steam-powered turbine. According to the idea, the system can recover 96% of stored heat.

New Scientist says it helps solve the problem of renewable energy such as solar and wind . As demand increases, they may not be able to meet the demand. Meanwhile, old ways of generating electricity, such as nuclear power, coal, or natural gas, are high heat losses.

However, according to scientists, the idea still has many loopholes . Although it contributes to reducing CO2 emissions, it is not an effective solution to reduce greenhouse gases. For 30 years, each " battery " saved only about 8 million tons of CO2 per year, equivalent to emissions from a large coal-fired power plant. Other issues such as project size, cost and efficiency when expanding, avoiding leaks .... are also of interest.