Solar installers could offer rooftop customers even more savings by bundling solar panels with heat pumps and other electric appliances, according to a recent study by the Rocky Mountain Institute.
RMI studied the carbon benefits and financial costs of electrification of home heating in four U.S. cities. The carbon reductions were pronounced in three of the four. The financial costs were harder to overcome—unless the electricity comes not from the grid, but from the rooftop.
"The customer just sticking with gas could be lower cost, lower lifetime cost, than converting to a heat pump," said Mike Henchen, a manager with RMI's electricity practice. "However, if we combine that electrification with installing rooftop solar in this case, we see a different outcome. It’s very capital intensive so there’s an additional $15,000 in this case for installing rooftop solar, but the long-term energy reduction is substantial and outweighs that and makes the solar-plus-electrification a winning strategy on cost overall."
Over 15 years, the heat pump saves the homeowner $24,900 when it's solar powered. And the carbon emissions fall to zero.
Following this strategy, solar installers could not only reduce a customer's electricity bill, they could also eliminate the gas bill by tackling all the tasks typically reserved for natural gas: space heating, water heating, clothes drying and cooking.
"This could be an opportunity for the solar companies to expand their business or upsell customers who are already looking to go solar," Henchen said.
When homes go completely electric the homeowner saves the monthly cost of a gas connection, which gets levied whether or not gas is used.
“One of the benefits we see in making the home all electric is that the customer can discontinue gas service altogether," Henchen said. "In one of the states… there’s a monthly fixed charge of over $30 for access to the gas system, and that monthly charge goes away entirely when the home becomes fully electrified, and so that’s an additional opportunity for savings.”
To achieve that, solar installers have to convince consumers to give up smaller gas appliances that they may prefer, like cooking ranges and clothes dryers. But Henchen recommends two technologies that could change their minds.