New Pumped Hydro Energy Storage System Needs No Mountains

The article discusses innovations in pumped hydro energy storage (PHES), a well-established method for storing electricity by using excess power to pump water uphill to a reservoir, which can later be released to generate electricity on demand. Traditional PHES systems require mountainous terrain to create sufficient elevation difference for efficient operation, limiting suitable site availability. Despite political support from the Trump administration for hydropower as part of a broader energy strategy, new dam construction remains challenging due to environmental and geographic constraints, and the administration’s energy emergency declaration controversially excluded wind and solar from baseload support, citing their intermittency. To overcome the elevation limitation, startups are developing novel PHES technologies that do not require mountainous sites. The UK-based company RheEnergise has created a compact system called HD Hydro (High-Density Hydropower) that can operate on low, hilly terrain without steep slopes. RheEnergise has identified thousands of potential sites in the US, especially in Texas, which could collectively provide significant energy storage