Harvest Thermal: Delivering on the Promise of Decarbonization
When we look back on the 2020s we will see clearly that the revolution to remove fossil fuels from the built environment was taking shape before our very eyes. Powerful tailwinds exist today for building decarbonization, from the recent enactment of the federal government’s Inflation Reduction Act to progressive building codes in California, New York, Massachusetts, Maine, Oregon, Washington, and British Columbia, and beyond.
Still, in many locales across North America, the outstanding home performance question is what will be the dominant technology to replace methane gas for the largest sources of energy consumption in the home: heating and hot water. Heat pumps are incredible, almost magical, machines, transferring as heat 3 to 5 times more energy than they consume—a remarkable improvement in energy efficiency compared to fossil-fueled appliances. Most gas furnaces on the market today have an efficiency factor of 0.8 and for gas water heaters, it’s around 0.5 depending on usage.
But, the unintended consequence of installing heat pumps for home heating and hot water is the additional demand for electricity, particularly during peak periods, when it often comes from dirty, nonrenewable sources. Imagine a typical, cold February morning when the alarm clock rings and families crawl out from under their covers into a warm room and step into a hot shower to start their day. With all-electric heating and hot water, that surge in electricity demand will come in the dark before solar energy ramps up. The grid of 2030 will be cleaner than today, but it will still have to rely on gas-fired “peaker” plants and “baseload” power for that early morning and early evening surge to heat our homes and fill our hot water tanks, and that energy mix will be invariably dirtier than mid-day energy.
How can we make all-electric space heating and hot water the cleanest, most sustainable solution while delivering significant savings on energy costs compared to gas? That’s the problem Harvest Thermal set out to solve. And, the solution had to be as convenient and comfortable, if not better, than current systems.
Harvest Thermal launched commercially in February 2022, and our systems are providing outstanding performance on par with our first five pilots (see “Ultra-Low-Carbon Hot Water and Space Conditioning”). With a dozen commercial projects deployed—18 total in variously sized homes—our system is cutting carbon emissions by 90% or more, compared to gas equipment, and by 50% compared to standard heat pump solutions. And, homeowners are achieving savings of up to 45% on their monthly heating and hot water bills—a huge win for the family budget (see Figure 1).