What is pumped hydro?
Pumped hydroelectricity is an increasingly useful energy storage option, allowing a flexible way to manage supply and demand of power. In standard hydroelectricity, water moves from a reservoir or river through rotating turbines, using gravity for propulsion. These turbines then produce electricity.
Pumped hydro operates on the same principle, and uses two dams, one higher than the other. The water is cycled, pumping water into the upper reservoir during off-peak hours or when excess energy is available, such as during the day with solar electricity. Potential energy is then stored and generated when it’s needed.
Pumped hydro can leverage price fluctuations. So, when electricity prices are cheap and demand is low, water in the low reservoir is pumped to the higher reservoir, where it is held until it is needed for generation. Alternatively, when both prices and demand are high, the water is released back into the lower reservoir, so this energy production is cheap and efficient, or profitable, if the power is being sold.