The costs of wind and solar electricity have dropped to a point that is not only cheaper than traditional electricity but cheaper than fuels. The need for grid-scale energy storage that can overcome the intermittent nature of wind and solar is now the biggest barrier for these renewable sources of energy. The startup Quino Energy, using technology developed at Harvard, employs a redox-flow battery to store electricity generated by renewables. Quino’s organic, water-soluble system makes it more affordable and practical than flow batteries that rely on costly metals such as vanadium. Other organizations are turning to brick-toasting heat storage devices to store excess electricity from renewables. MGA Thermal’s blocks store excess renewable energy as heat, and turbines convert it back into electricity on demand. Rondo’s brick toasters also capture intermittent electricity from solar and wind as thermal energy. Italy-based Energy Dome plans to store excess renewables using carbon dioxide. Under heavy pressure, carbon dioxide converts to a liquid, which can be stored in steel tanks. When energy is needed, the carbon dioxide is decompressed, powering a turbine that results in electricity.
Grid-scale energy storage