Pumped Hydro Energy Storage: A Renaissance in Renewable Energy
The world is embracing renewable energy sources, and with that comes the need for innovative solutions to balance supply and demand. One such solution is pumped hydro energy storage, a centuries-old technology that is experiencing a renaissance. In a quiet corner of Devon, England, workers are mixing a special fluid that can store energy, blending it with utmost care to achieve a mixture 2.5 times denser than water.
This fluid, when combined with a china clay mine near Plymouth, can drive turbines to create electricity. The system, developed by RheEnergise, a British energy-storage company, showcases a new take on pumped hydro. By pumping the mixture back up during times of excess energy, the system can store energy for short or long periods, filling in shortfalls in electricity generation or soaking up surplus energy.
Pumped hydro first emerged in the late 19th century, designed to complement fossil fuel power plants. Today, grid operators value it for its ability to mediate highly variable wind and solar assets. However, building pumped hydro plants has often been expensive and difficult. RheEnergise's denser-than-water fluid allows for more potential energy to be packed into a smaller space and at lower elevations, making it a more viable option.
The company estimates that there could be hundreds of thousands of potential locations for its technology worldwide, if it can prove its effectiveness. RheEnergise has already generated power from its system and aims to follow up with a commercial-scale 10 MW project by 2028. This is just one example of how pumped hydro is evolving, with an estimated 600 GW of projects in the global pipeline.
Vattenfall's Goldisthal facility in Germany is another example of the power of pumped hydro. It can provide 1.06 GW of electricity for up to nine hours and can switch from standstill to full generation in just 90 seconds. The plant's ability to alternate between generation and pumping modes in minutes makes it a valuable asset for the energy grid.
Despite the challenges of construction, pumped hydro remains a highly profitable and viable solution for energy storage. Countries like Australia are investing in massive projects like Snowy 2.0, which will offer an astonishing 350 GWh of energy when completed. However, such projects face delays and cost overruns, highlighting the complexity of large-scale infrastructure.
As the world accelerates its transition to renewable energy, pumped hydro energy storage is poised to play a crucial role. With its ability to balance supply and demand, store energy, and complement variable renewable sources, it is a key component in the global energy transition.
