It’s estimated that there are over 118 million hot water heaters in American homes. Nearly 54 million of them are electric. Whether it’s gas or electric, it’s keeping water hot for us all the time—and most of that time we don’t need it.

So, what if those water heaters – the electric ones – could all be hooked up to the same grid as utility power, so they could be told when energy is plentiful and heating the water would be the least expensive? That’s the idea behind what’s known as Grid-Integrated Water Heating (GIWH). Several states have started pilot programs to test its viability. Here’s how it works.

Only When It Makes Good Dollars And Sense

Most people use hot water only in the morning and evening hours. The rest of the time, your water heater is running to keep water hot for no reason. When you think about it, that’s a lot of wasted energy.

The idea behind GIWH is that our water heaters would be told when to heat the water to match available energy production. Heating it a night would take advantage of high wind production. Heating it at midday would take advantage of increased and abundant solar production.

It doesn’t mean we could end up with no hot water when we want or need it. Today’s residential water heaters have much better thermal efficiency—they’re able to keep hot water hot for much longer periods of time. So, the “always on, just in case” mode of the water heater switches to “only on when it’s cost effective.”

The Customers Are The Winners

According to the Rocky Mountain Institute, connecting our electric water heaters to the grid could free up about 100,000 MW of additional variable wind and solar energy that can be used for other purposes.

It’s estimated that up to 60% of the electricity demand used for water heating could be redirected. That’s a saving for customers because it would help utilities avoid reaching their generation capacity, as well as avoid wasting renewable energy captured but not stored.

Study And Pilot Testing

Everybody has to get on board for this idea to work—and that means water heater manufacturers must see the upside to participation, too. They would have to agree to build an inexpensive $5 microchip into their designs.

The ultimate value to them, of course, is customer satisfaction. And speaking of customers, the biggest pushback seems to be the concern that turning control of their water heaters over to the utility company might mean there’s no hot water when they want it. That’s not the case. Your water heater stores it efficiently for later use.

Just to be sure, utility pilot programs already underway have gotten past this pushback by including a convenient override utility accessed by what else – your smartphone.

If you’re a local business, there’s a way you can start saving on utilities without waiting for your hot water heater to join in on the effort. You can see significant savings by subscribing to one of our solar gardens. The program gives you savings of up to 10% on office utility bills. There’s no cost involved for your company, and no solar panels on your rooftop, either. Read more about it here.