Iberdrola, a leading company in the production and distribution of electricity and natural gas in Spain, has developed a system to solve the problem of energy storage, derived from renewable sources, with hydroelectric accumulations.
In Spain, wind energy has increased by 14% over the last 10 years, and the solution for accumulations is the investment in hydroelectric pumped storage plants, like Cortes‐La Muela, on the Júcar river.
With a system of dams, Iberdrola closed a basin at an altitude of 900 m and another one 500 m below, creating the largest hydroelectric pumped storage plant in Europe, with a power of 1,762 MW, which can cover the needs of 500,000 homes.
Water, passing through the turbines and producing electricity, can be brought from the downstream to the upstream basin with a pumping system when demand is low, then return to the valley when demand is higher.
It basically accumulates excess energy and then releases it in times of need. This has also caught the attention of utilities, which are now willing to invest in renewable energy.
Spain is not the only one to offer this service, though. There are 292 hydroelectric pumped storage plants in the world and additional 46 are under construction. The goal is to reach 325 by 2030. Italy with its power plants in the Alpine region generates 8 GW per year, out of a total of 142.
In Europe, the most important projects are in Germany, Austria, Switzerland and Portugal, while in the USA there are two power stations under construction in California.
Hydroelectric accumulations are growing especially in China, where 15 power stations are under construction and one is particularly promising. It’s the Fengning Pumped Storage Power Station, with an installed capacity of 3,6 GW, which is going to be the world’s biggest pumped‐storage hydroelectric power station when will be completed by 2022.