Founded in 2017, Energy Vault stores energy using a system of electric motors and large blocks, each weighing 35 metric tons. The blocks are lifted from the ground when electricity is available or cheap and then lowered — running the process in reverse — when power is needed. The startup has so far installed one such commercial-scale system, in Switzerland.
Each of the facilities Energy Vault will build for DG Fuels will deliver 50 megawatts to 75 megawatts of electricity for eight to 10 hours, Piconi said. Large-scale lithium-ion batteries, in contrast, usually run for just four hours before they need to recharge. DG Fuels will use the facilities to store solar power needed for part of its fuel-making process.
Energy Vault last month announced it would go public by merging with Novus Capital Corp. II, a special purpose acquisition company. The transaction would give the combined company an implied pro-forma enterprise value of $1.1 billion and provide up to $388 million in gross cash proceeds.