One of the most significant actions a person can take to fight climate change is to swap out their fossil fuel-fired furnace or boiler for electric heat pumps. But while rebates and other subsidies can help defray the up-front cost of the switch, the price of electricity relative to natural gas is still a major deterrent in many places. Lower emissions for higher monthly bills is not much of a tradeoff.
Could the solution be as simple as utilities giving heat pump users a discounted rate in the winter?
There’s a growing consensus among climate and clean energy experts that this is a crucial and urgent step toward decarbonizing, at least in the near term. A number of recent reports make the case not just that discounted rates for heat pump users will help spur adoption of the technology, but also that these customers are currently being overcharged.
The reason why is that today, most utilities operate in “summer peaking” systems, where electricity demand is highest on the hottest days of the year. Utilities spend lots of money on infrastructure like power plants, substations, transformers, and wires to make sure they can deliver power reliably on those days. But in the winter, a lot of that stuff sits unused. So it doesn’t increase overall system costs for people to use more electricity in the winter.
In fact, “it’s less expensive to offer electricity in the winter in summer peaking systems,” Matthew Malinowski, who directs the buildings program at the nonprofit American Council for an Energy-Efficient Economy, told me. And yet a lot of utilities charge customers a flat rate, no matter the time of year. “It seems only fair to charge people less for the electricity they use in the winter,” Malinowski said.
Some utilities are already starting to do this. Malinowski and his colleagues published a study on Tuesday that used real utility rates to examine the current cost of operating heat pumps in four cold-weather states. Their modeling illustrates how heat pump-specific rates can make the technology much more attractive compared to natural gas-fired heating. (Households switching from fuel oil or propane heating to heat pumps will almost always save money.)
The first state they looked at, Maine, has famously had a lot of success getting residents to switch to heat pumps. It turns out favorable rates may have been a big part of that. The cost of electricity there is not much higher than natural gas, so when a household there switches to heat pumps, its annual bills remain roughly the same. Additionally, Maine’s biggest utility recently ran a pilot program where it offered customers the option to sign up for a “heat pump rate,” giving them discounted electricity in the winter and slightly higher than normal electricity in the summer. The study estimated that an average household in Maine using this rate would save just over $200 per year compared to one that heats with natural gas.
Just 6% of households in Maine used heat pumps a decade ago, before the state began offering incentives. As of last year, that number had grown to 26%, although many homes still use natural gas boilers and furnaces as back-up systems.
The other three states the study focuses on — Minnesota, Colorado, and Connecticut — have much higher electricity rates relative to natural gas, and simply switching to a heat pump would not be economic. But Minnesota has a winter pricing program similar to Maine’s. The utility Xcel offers a deeply discounted rate to customers who heat their homes with electricity through the colder months, whether they use heat pumps or less efficient electric resistance systems. The report estimates that heat pump users who opt-in to this rate will save about $400 per year compared to if they heated their homes with natural gas.
Xcel is also the largest utility in Colorado, where it does not yet offer a winter discount rate. There, the authors calculate that heat pumps currently cost about $500 more per year than natural gas heating. But a new law in Colorado requires utilities to submit new heat pump-specific electric rates to regulators for approval by 2027. If Xcel offered the same discount as it does in Minnesota, that would bring heat pump operating costs roughly on par with gas heating.
Colorado isn’t the only state actively pursuing heat pump-specific rates to spur adoption. In Massachusetts, which the study did not look at, a small utility called Unitil began offering a discounted heat pump rate on March 1 of this year, and regulators are requiring National Grid, which serves about 15% of the state, to offer one beginning next winter.
Meanwhile, in Connecticut, electricity prices are so much higher than gas prices that the authors conclude that “rate interventions are ultimately not enough” to make heat pumps competitive. “The state needs deep investment in making electric power more affordable to its residents,” they write, such as “taking on some costs of grid maintenance and upgrades, putting a price on carbon, or implementing clean heat standards.”
One caveat to the study is that it uses electric rates in 2024 but meteorological data from 2018. Since the world was notably warmer last year than in 2018, the authors’ cost estimates are likely conservative. In reality, heat pumps may already be more affordable than the study makes them seem.
Another is that heat pump-specific rates are only really a solution for the next five to 10 years. As more households adopt heat pumps, the electric grid will begin to shift toward a winter-peaking system, and there won’t really be a case to charge heat pump users less. Massachusetts regulators have acknowledged they will need to monitor this and re-evaluate heat pump rates regularly as the situation evolves.
“We’re just responding to the situation today,” Malinowski told me. “Heat pump penetration is very small, and those users are overpaying based on the service they're demanding of the grid, and what they're providing to the grid, which is revenue during off-peak times when electricity is cheaper to provide.”
Metrograph
IEA