t’s not a new concept: When a wind turbine or solar array generates more energy than you’re using, the excess energy can be stored by pumping water into an elevated holding tank, converting kinetic energy into potential energy. When energy is needed, the water flows down and spins a turbine that generates electricity.
Engineers at MIT are proposing a similar system for off-shore wind turbines, but instead of an elevated holding tank, the water would be stored in a 25 meter concrete spherical tank that also anchors the floating turbine to the ocean floor. The sphere is placed at a depth of 400 meters. Excess electrical energy pumps water out of the tank and into the ocean, and when energy is needed the water flows back into the sphere and drives a hydroelectric generator.
