What the business is
Sells a control pod with a heat pump and a 119-gallon hot-water tank that stores heat when solar or cheap power is plentiful.
The bet
That a smart controller plus a big water tank beats batteries for running heat pumps on cheap, clean power.
Starting capital
$4M seed led by Earth Foundry with MUUS Climate Partners, Starshot Capital and Portfolia
How it started
Founded in 2019, the idea came when co-founder and CEO Jane Melia, an engineer with a fluid dynamics doctorate and ex-solar startup staff, faced a dying gas furnace in her Berkeley home. She wanted to avoid gas but found that two on-demand heat pumps, plus a battery to use cheap power, was unaffordable.
What happened
She and her co-founders built a system integrating a heat pump and hot water storage tank with controls: flow meters, temperature sensors and electronics modeling the tank's fluid dynamics to know its temperature within 4 degrees F. It heats the tank when solar is humming, then draws on it at night, accounting for home size, occupants, usage and forecasts.
How it ended up
By October 2023 Harvest Thermal had installed more than 100 systems in California and Oregon, and Melia said customers typically save 30% on bills.
What has to be true
Melia wanted to rid her home of gas but found two on-demand heat pumps felt inelegant, and a battery to use cheap solar would be unaffordable.
The Inflation Reduction Act includes thermal storage provisions, though it wasn't yet clear how they apply to homeowner systems.
Customers on time-of-use pricing, Melia said, typically save 30% by running the heat pump when power is cheapest.
What can be applied
You don't have to reinvent the hardware: sometimes the lever is the software that decides when an existing machine runs.
Aftermath
As of 24 October 2023, Harvest Thermal had a $4M seed to extend runway while it sought more installers and customers. TechCrunch noted its main hurdles appeared to be winning installers, who recommend systems when homeowners replace old ones, and that a heating unit and water heater must be replaced together. Savings and cost claims are Melia's.
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