Energy Vault Holdings (NYSE:NRGV) +16.6% in Wednesday's trading after CEO Robert Piconi told Bloomberg it will complete its first major power storage project, in Rudong, China, by September. Energy Vault (NRGV) uses electric motors to elevate heavy blocks that weigh as much as 35 tons, which creates potential energy that can be converted later into electricity when they are lowered to the ground – a concept is similar to widely used pumped hydroelectric plants. Piconi told Bloomberg the Energy Vault (NRGV) technology is the first to provide an alternative long-duration storage system based on gravity. Earlier this week, Energy Vault…