From Passive House to Your House

I’ve been touting the dramatic emission reductions and bill savings from the Harvest Pod for months -- and now the data is in. Passive House Magazine published my article with results from 5 Bay area pilots and it confirms what I’ve been saying: Carbon emissions were down 90% compared with gas and 50% compared with a standard electric heat pump for home heating and hot water.  Bills were on average 35% lower than gas usage and about 30% lower than a standard electric heat pump system.

As readers of this space well know by now, the Harvest system “harvests” electricity when it’s cleanest and cheapest, managing a single heat pump to heat water in a regular hot water tank. The tank operates as a thermal battery with enough reserve so there is plenty of hot water available for showers, dishes, etc. whenever it’s needed

To deliver space heating, the hot water is run through an air handler that blows warm air through existing ductwork ( or through pipes for a hydronic system). As I say in the piece, we optimized every part of the Harvest system for the 4 Cs: cost, comfort, control, and…carbon.

Next up for Harvest Thermal: We will be deploying up to 31 demonstration sites in partnership with the California Energy Commission and Peninsula Clean Energy starting this fall, before expanding to further homes early in 2022. Stay tuned!