Home Gas effect The climate mathematics of home heating electrification

The climate mathematics of home heating electrification


For this reason, the study finds excellent climatic performance throughout the life cycle of heat pumps. Here’s how it works: an average heat pump installed this year will last about 15 years, or until the 2030s. clean electricity by 2035, although the authors used Cambium’s “low cost renewable energy” scenario, which only incorporates 70% clean energy by 2050. Regardless, the Heat pump emissions will decline rapidly over its lifetime as the grid grows with clean energy resources. For these reasons, heat pumps are a climate-smart choice to install today.

For HFC refrigerants, there is similar good news. First, a quick primer: HFCs are super potent greenhouse gases – weight for pound they are thousands of times more potent than carbon dioxide – used in air conditioners and heat pumps to help to create the cooling and heating effects.

Due to the environmental impact of HFCs, the US is embarking on an 85% economy-wide phase-down of HFCs over the next 15 years under the US Innovation and Innovation Act. manufacturing (AIM). Under this program, heat pump manufacturers will soon switch to models with more climate-friendly refrigerant alternatives. Avoidable refrigerant emissions should also be reduced as HFCs become rarer and therefore too expensive to waste. The NRDC also advocates for policies to increase the recovery of end-of-life refrigerants and promote the repair of leaks. Like the study as a whole, these HFC refrigerant leak projections are specific to monosplit heat pump units installed in residences and do not speak to potential issues with other types of systems, such as residential and commercial systems. larger ones built on site which can have considerably higher leak rates.

The study assumes that for the next few years, heat pumps will continue to use current HFC refrigerants before switching to more climate-friendly refrigerants around the middle of this decade. Both before and after this change, the climate benefits of electrifying heating far outweigh any potential additional risk from refrigerants. Here’s why: Most American homes already have some type of air conditioning, which uses the HFC refrigerant itself, connected to the furnace. In these cases, replacing a furnace with a heat pump is only “responsible” for the additional refrigerant needed. Which is not much, find the authors.

In summary, while we need to move quickly away from today’s HFC refrigerants, that shouldn’t stop an unrestrained push to electrify with heat pumps.


Finally, a significant fraction of the benefits of switching to heat pumps comes from the reduction of fugitive methane emissions associated with burning gas in a domestic boiler. Methane leaks at every step of the supply chain, from the extraction well to the treatment, to the distribution, to the meter, to the piping in the house and at the burner itself. The study finds that when looking at the climate impacts of methane over 20 years, methane leaking into the atmosphere contributes to climate impacts almost as much as methane that is burned for heat. This metric clearly works in favor of heat pumps, even considering that for some time gas will leak on its way to a power plant to power the heat pump. This effect decreases with the increasing share of renewable energy sources.

Taken together, the numbers clearly show that it’s time to electrify our heat. Overall, the population-weighted average of 99 U.S. cities in the study shows a 53-67% reduction using a 20-year global warming potential (GWP) for HFCs and methane, a reduction of 44-60% using a 100-year GWP, and a 38-53% reduction for CO2 alone (i.e. excluding results for HFCs and methane, although we don’t advise to do).

As you might expect, emission reductions are best in the Pacific and Northeast regions, which already have fairly clean networks. But the results are remarkably consistent across regions, and no major climate zone in the country shows less than a roughly 45% reduction using 20-year GWP values. Select regions start at up to 72% off for units installed today.

So what’s the next step?

It’s time for policymakers in every state and in Washington, DC to mount a full court press to get heat pumps deployed in our homes and buildings. A good first start would be the incentives for heat pumps in the Build Back Better Act climate package, which Congress is expected to pass. Consumers looking for a new air conditioning or heating system should choose a heat pump if they can. The best time to do this is when it’s time for a new central air conditioner, as it only costs a small fraction more to get a heat pump that provides both cooling and heating instead. That’s a great deal on a brand new heating system that will save you money and your children’s future. Replacing a burnt out oven is also a good opportunity.

Heat pump manufacturers should prepare as soon as possible for a full transition to heat pumps, and in particular models that use more climate-friendly refrigerants. It is also a good time for manufacturers to improve the energy efficiency of their models and limit the additional refrigerant charge needed in their heat pump models.

And, of course, for the study’s predictions to be true, we will need to continue to make rapid progress towards our other climate goals: choosing efficient appliances, greening the grid, reducing methane leaks and reducing the climate impact of refrigerants. HFCs. We need to work on these issues in parallel if we are to succeed in making the future climate impact of home heating as close to zero as possible.

This winter, take a moment to think about where the warmth that keeps you warm comes from. Let’s all find a better way.