Carbon dioxide could finally have the possibility of becoming a solution to the climate crisis rather than one of the causes. An Italian company Energy Dome says that its new long-duration “CO2 battery” system will store energy at less than half the cost of lithium big batteries while also being very responsive to load demand.
Energy Dome is building the pilot plant on the island of Sardinia, Italy, expected to be launched in early 2022. It is still a 2.5 MWe and 4 MWh prototype, although it is intended to increase in the coming years to be able to store 8 MWh or more. The Demonstration Plant will use the same component parts as the full-scale commercial system of 25MW and 100MWh or 200MWh, effectively proving the readiness of this technology for the market.
Energy Dome will deploy the demonstration plant by pioneering an innovative alternative to batteries for utility-scale energy storage. The team took on the challenge of developing a solution that would not only be technologically and economically feasible now but would also overcome the inherent limitations of the lithium-ion. In particular, the CO2 battery does not present a fire risk, uses no rare materials, and combines better performance with a lower capital cost compared to Li-Ion.
Energy Dome’s patented solution stores energy in the form of liquid CO2 in pressurized vessels. The CO2 battery technology is based on a closed-loop thermodynamic process that efficiently stores energy by manipulating CO2 under different state conditions. This battery can work in charging mode, absorbing energy from the network, and returning energy to the network in discharge mode.
In charging mode, CO2 is compressed and stored under pressure at room temperature in a high-density liquid or supercritical state. In discharge mode, the CO2 is expanded in a turbine and stored again in an atmospheric gasifier, releasing the energy to the grid in a closed-loop system, with zero-emission to the atmosphere.
The CO2 Battery Demo plant will both prove the efficiency of the technology and the ability of the technology to provide energy and regulation services in the electrical grid, by testing the technology at a relevant scale and by overcoming the technical risks, which mainly refer to the risk of component integration (TRL 9).
The battery can reportedly offer a Levelised Cost Of Storage (LCOS) as low as US$50-60 per MWh within a few years, where lithium batteries are sitting between US$132-245/MWh. Besides, Energy Dome’s thermodynamic liquid-CO2 system has a round-trip efficiency of 75-80% – higher than any other long-duration energy storage technology currently on the market, including liquid-air, compressed-air, and gravity-based solutions.
“It’s a remarkable milestone being ready to show and prove our technology after only one and a half years from Energy Dome’s incorporation,” said Claudio Spadicini, Energy Dome CEO. “The uniqueness of the CO2 battery lies not only in the innovative thermodynamic process of storing energy by liquifying CO2 at ambient temperature but also in the process itself. This, using off-the-shelf equipment, will prove that our technology is ready, and initial market signs suggest a rapid global take-up by leading power sector operators.“