Longer-term energy storage remains inconvenient; thus, much battery research has focused on “how rapidly can we charge those batteries so You can drive your EV for yet another couple of miles?” That’s a far different situation than attempting to capture the sun’s power for 12 hours before releasing it for another 12 hours as the moon takes a leisurely stroll across the night sky. Energy Dome announced the completion of its Series A funding round worth $11 million, with the goal of constructing the world’s first commercially effective CO2 battery in a pilot scheme in Sardinia, Italy.
According to the firm, the optimal charge/discharge cycle for a CO2 battery is four to 24 hours, making it ideal for daily as well as intra-day cycling. It emphasizes that this is a rapidly developing market area that is underserved by current battery technology. The goal is to charge your CO2 battery during the day when excess of solar-generated energy is available, then discharge it during peak evening and midnight hours when demand for electricity exceeds what solar can supply.
The business claims that the CO2 battery they own, achieves a 75 percent to 80 percent round-trip efficiency utilizing standard components. Perhaps more intriguing is the fact that the batteries’ operational life is expected to be in the range of 25 years. If you’ve been keeping a watch on some other power-storage solutions, you’ve probably seen that by the time it reaches the one-decade mark, most other solutions start to degrade dramatically. According to the company, the price of storing energy with equivalent-sized lithium-ion batteries will be around half the expense of storing it with its device during its entire duration.
The technology is very cool: CO2 is used in a cycle that is closed-loop, that converts it from gas to liquid then back to gas. The company is named after solution’s “dome” component, which is inflatable atmospheric gas container loaded with CO2 in gaseous state.
When the system is charging, it uses electricity from the grid to operate a compressor that extracts CO2 from the dome then compresses it, producing heat. A thermal power storage device is used to store the heat. To complete the charging cycle, the CO2 is liquefied under pressure then stored in liquid CO2 tanks at room temperature. When the cycle is discharged, the liquid CO2 is evaporated, the heat from the thermal energy storage system is recovered, and the hot CO2 is expanded into a turbine that drives a generator. The energy is returned to a grid, and that the CO2 is used to re-inflate the dome without releasing CO2 into the atmosphere, making it prepared for the next charging cycle. The system can store a maximum of 200 MWh of energy.