Renewable energies are not perfect–they are intermittent sources that cannot produce energy on demand. Instead, when they are producing energy for the grid, they do so at an extremely low cost. Our grid must be able to utilize these renewable resources when they are plentiful or store the energy for when it is in greater demand. Energy storage facilities store this excess energy when it is in high supply and discharge it when it is in high demand. Batteries can help the power grid levelize these daily peaks in energy usage and production to streamline the energy market.