As green energy begins to take over the world's electricity supply, large-scale energy storage will be required all over the world. Renewable energy is often generated at unnecessary time and place. Various grid level storage technologies are competing for the niche of various energy markets, each of which has its own advantages and disadvantages.
In July last year, energy dome introduced its carbon dioxide battery technology. Its core is that carbon dioxide will expand rapidly when it changes from liquid state to gas state, and it can only stabilize at a pressure at least five times higher than the earth's atmospheric pressure. How big is it? At room temperature, 2.5675 liters of liquid carbon dioxide will expand to 1000 liters of gaseous carbon dioxide at 56 atmospheres. This is nearly 400 times the coefficient.
The battery of the energy dome uses a huge dome with a large, flexible bag filled with carbon dioxide gas. It uses energy to run the electric compressor, extrudes the gas into smaller and smaller volumes, and finally condenses it into a liquid, which is stored at ambient temperature, thus "charging" the battery. This charging process generates waste heat, which is collected in the thermal energy storage system.
As long as the pressure remains constant, carbon dioxide will be there for a long time. When energy is needed, the system uses its stored heat to evaporate carbon dioxide. When the carbon dioxide expands to the dome, a group of turbines feed back the energy to the grid. According to energy dome, the roundtrip efficiency of this solution is more than 75%. In this respect, it cannot compete with large lithium batteries. However, in the energy field, cost is the king. The company told recharge news that its levelized storage cost will reach $50-60 per MWh in a few years, much lower than $132-245 per MWh using lithium batteries.
Some solutions can store energy more cheaply, but their response to demand is usually slow, which is more suitable for long-term seasonal energy production and demand mismatch. These "carbon dioxide batteries" can be closer to the immediate response of lithium batteries, with longer energy storage time and less system degradation.
So there was this pilot plant. The company announced last year that after its establishment in february2020, it would build its first plant in Sardinia and put it into operation before 2022. The company did it with astonishing speed. The Sardinian plant is quite small. It only stores 4 megawatt hours of energy and the maximum output power is 2.5 megawatts. However, the company said that it has proved that this concept is feasible, and that it is built using ready-made equipment anywhere in the world, which shows that there is no obstacle to large-scale global promotion.
The next step of energy dome is to build a full-scale plant to store 200 megawatt hours of energy and provide up to 20 megawatts of energy when needed. Energy dome said that its first full-size plant is expected to be completed and operated by the end of 2023. It has sold plants in Italy, Germany, Africa and the Middle East, and it is conducting round B financing to help it expand its scale in commercial operations.