One of the primary challenges that the energy transition faces is the storage of electrical power. Why? Electricity in the grid must be in near-perfect balance of supply and demand with only a couple of seconds to adjust or voltage and frequency problems will occur. Because of the intermittent nature of power sources like solar or wind power, they cannot be turned off and on to match demand. After all, we can’t generate these kinds of energy when the sun isn’t shining or the wind isn’t blowing. This has created a high demand for energy storage systems. Pumped storage hydropower can help.