Pumped hydroelectric energy storage (PHES) facilities contribute to environmental benefits largely due to their high efficiency, which enhances their effectiveness as a grid energy storage system. The round-trip efficiency of these systems—meaning the ratio of energy output during generation to energy input during pumping—typically ranges between 70% and 80%, with some sources citing efficiencies over 80%. This relatively high efficiency means that a large portion of the electricity used to pump water to a higher reservoir is recoverable when the water is released to generate electricity later.
How Efficiency Enhances Environmental Benefits:
- Supports Renewable Integration: The ability of pumped hydro to efficiently store surplus energy during periods of low demand—often when renewable sources like solar and wind produce excess electricity—and release it during peak demand helps balance the grid and reduces reliance on fossil fuel “peaker” plants. This smoothing of intermittent renewable power increases the overall utilization of clean energy.
- Reduces Carbon Emissions: By storing renewable energy and providing reliable power on demand, pumped hydro facilities help avoid the need for fossil fuel backup plants, thus cutting greenhouse gas emissions associated with electricity generation.
- Long Duration and Large Capacity: Pumped hydro can typically provide up to 10 hours of electricity output, significantly longer than most battery technologies. This enables it to cover longer periods of renewable intermittency, reducing the need for fossil fuel reserves and supporting deeper decarbonization of the electricity sector.
- Economic Efficiency Reinforces Environmental Gains: The cost-effectiveness of pumped hydro storage compared to other technologies means more extensive deployment is financially feasible, thereby accelerating the transition to low-carbon energy systems.
In summary, the 70-80% (and sometimes above 80%) round-trip efficiency of pumped hydro storage maximizes the useful recovery of stored energy, enabling it to act as a highly effective “green battery” for integrating renewable sources, stabilizing the grid, and reducing carbon emissions. This efficiency underpins its role as the dominant form of large-scale grid energy storage worldwide and a key enabler of cleaner, more resilient power systems.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-does-the-efficiency-of-pumped-hydroelectric-energy-storage-facilities-contribute-to-their-environmental-benefits/
