Longer-term energy storage is a drag, and a lot of battery technologies have focused on “how fast can we charge these batteries so that I can drive my electric vehicle a few hundred more miles.” This is a fundamentally different problem than trying to capture the power of the sun for 12 hours, before releasing the power for the next 12 hours as the moon makes its lazy walk against the night sky.
Energy Dome today announced it has closed its $ 11 million Series A fundraiser, with the goal of deploying the first commercially viable CO2 drums in a demonstration project in his native Sardinia, Italy.
The company told us that a CO2 The battery’s optimal charge / discharge cycle ranges from four to 24 hours, which positions it perfectly for daily and intra-day cycling. He points out that this is a rapidly growing market segment, underserved by existing battery technologies. Specifically, the hope is to charge the CO2 battery during the day when there is a surplus of solar energy, before discharging during peak evening hours and at night, when the demand for electricity exceeds what solar energy can provide. Because, well, I would hate to feel the need to explain it to you, but there is no sun at night.
Built using basic components, the company claims its CO2 the battery achieves a round trip efficiency of 75-80%. But what is perhaps more interesting is that the operational life of the batteries should be around 25 years. If you’ve kept an eye out for other energy storage solutions, you will have noticed mentally that the operational lifespan of most other solutions begins to deteriorate dramatically by the time it hits the ten-year mark. The company predicts that, given the full lifecycle cost of its product, the cost of energy storage will be about half the cost of storage with lithium-ion batteries of similar size.
The technology is pretty cool – the company uses CO2 in a closed loop cycle where it switches from gas to liquid and back to gas. The company itself is named after the “dome” component of the solution – an inflatable atmospheric gas tank filled with CO.2 in its gaseous form.
When charging, the system draws electrical energy from the power grid, which drives a compressor that draws CO2 of the dome and compresses it, generating heat. The heat is stored in a thermal energy storage device. CO2 is then liquefied under pressure and stored in liquid CO2 containers, at room temperature, to complete the charging cycle. When discharging, the cycle is reversed by evaporating the liquid CO2, recovering heat from the thermal energy storage system and expanding the hot CO2 in a turbine, which drives a generator. The electricity is returned to the grid and the CO2 re-inflates the dome without emissions into the atmosphere, ready for the next charging cycle. The system has up to 200 MWh of storage capacity.
The round was led by high-tech venture capital firm 360 Capital, while a number of other investors round out the investment round, including the Sustainable Impact Capital program of Barclays, a division of the giant. Barclays bank that takes a Geneva-based, multi-family, impact investing approach to Novum Capital Partners and Third Derivative, a global climate technology startup accelerator founded by RMI and New Energy Nexus.