The intermittency problem is the biggest barrier to renewable energy generation. We cannot run our economy solely on wind and solar energy because there are too many times when the sun is not shining and the wind is not blowing. So, like it or not, until such time as new Grid-level battery storage technology can be developed, we have no choice but to carry on burning coal and gas to keep the lights on.
However, there is an energy storage technology that is so obvious that nobody is paying it any attention according to America’s National Rural Electric Cooperative Association. In a test of community energy storage “batteries” in 65,000 households in Minnesota were able to store a gigawatt of power overnight.
What are these batteries that are so obvious that none of us notices them?
Electric water heaters!
Gary Connett, director of member services at Great River Energy, the community energy cooperative engaged in the research, explains:
“At Great River Energy, we believe there’s a battery hidden in basements all across our service territory. When the wind is blowing or the sun is shining, large capacity water heaters can be enabled to make immediate use of that energy to heat water to high temperatures. The water heaters can be shut down when renewables are scarce and wholesale costs are high.”
Because water heating accounts for 15 percent or more of household energy use, smart boilers (which can be controlled remotely) can be used as a form of thermal energy storage. This means that households can be provided with hot water without the need to draw on grid electricity when generating capacity is low.