The cost of both solar and wind power continues to drop making the two renewable energy sources the cheapest way to make electricity in more and more places. Given the virtually inexhaustible supply of both wind and sun power, these clean electricity sources can in principle meet all our energy needs. The hang up is that both of them are intermittent sources – the wind doesn’t blow all the time and the sun doesn’t shine all the time.
The solution to the intermittency problem is energy storage. If energy produced by wind and sun can be stored so it can be made available for use at any time, then the goal of having 100% clean energy can be realized.
Energy storage technology has continued to improve over time and to get cheaper. The Department of Energy recently announced a new initiative aimed at accelerating both of these trends.
The new program – called Long Duration Storage Shot – has the goal of reducing the cost of grid-scale, long-duration energy storage by 90% within this decade.
Long-duration energy storage is defined as systems that can store energy for more than ten hours at a time. Such systems can support a low-cost, reliable, carbon-free electric grid that can supply power even when energy generation is unavailable or lower than demand. With long-duration storage, solar-generated power can be used at night.
The program will consider multiple types of storage technologies – electrochemical (that is: batteries), mechanical, thermal, chemical carriers, and various combinations thereof. Any technology that has the potential to meet the necessary duration and cost targets for long-term grid storage are fair game for the program.
Photo, posted October 16, 2017, courtesy of UC Davis College of Engineering via Flickr.