Energy storage systems are a buffer between the intermittent supply of renewable energy and consumer demand. Renewable sources like wind and solar produce sustainable energy, but their production is inconsistent, and the electricity they produce needs to be utilized upon generation. Energy storage solutions – most commonly in the form of battery energy storage or pumped hydro systems provide a reliable partner for these sources, bridging the gap when these energy sources are producing power and when that power is needed by the market.
Pumped hydro (water) and compressed air are other technologies that allow for energy storage. All three of these technologies can be employed to capture and store energy when it is being produced in abundance, like on a very sunny or very windy day, allowing that same energy to be consumed when the sun goes down or the wind isn’t blowing. An additional benefit of Energy Storage is that it can reduce curtailment, which occurs when renewable electricity generators such as wind and solar are forced to slow or shut down production because there is simply more energy available than the grid is able to transport and distribute. As described above, energy storage can alleviate the need for curtailment, improving the efficiency of renewable energy sources and the flexibility to use the energy when it is needed.
Compressed air energy storage (CAES) is a way to store vast amounts of energy by using electricity to compress air and store it in large underground caverns or tanks. When energy is needed, like during peak demand times, the compressed air is released, heated, and used to spin a turbine to generate electricity.
It works a bit like a battery, but instead of storing energy chemically, it stores it as high-pressure air. CAES can help balance the power grid, especially when combined with renewable sources like wind and solar, by storing excess energy when supply is high and releasing it when demand increases.
Pumped hydro storage is a method of storing energy by using two water reservoirs at different elevations. When there’s extra electricity, like from solar or wind, it’s used to pump water from the lower reservoir up to the higher one. Then, when electricity is needed, the stored water is released back down through turbines, generating power.
It’s like a big, rechargeable battery that uses gravity and water instead of chemicals. Pumped hydro is one of the most widely used and reliable forms of large-scale energy storage, helping to keep the power grid stable and flexible.
Pumped hydro storage is gaining momentum across the U.S. as a reliable method to store renewable energy and stabilize the power grid. The Seminoe Pumped Storage Project in Carbon County is a 900 MW project designed to complement local wind energy.
