Compute installed inside the buildings it heats — running on surplus electricity, turning it into affordable hot water. Productive when it runs, harmless when it stops.
The Heat21 Node
Scotland pays wind farms to switch off when the grid can't carry their power. Heat21 puts that surplus to work: SHA-256 compute runs on a building's existing supply and captures essentially all the heat it makes.
The Node runs on the building's existing electricity supply, drawing hardest when the grid has power it would otherwise pay to waste.
A hydronic cold-plate captures 96.2% of the heat the hardware produces and moves it into a water-tank heat battery.
The tank holds up to 90°C water, so even a flexing load delivers steady heating and hot water whenever the home calls for it.
Going electric is the obvious answer — but heat pumps won't fit many homes, and resistive heat is costly to run. Here, the hardware that heats the water also earns from computing, paying the cost down.
Every watt does useful work before it warms the tank. The compute pays for itself while it heats — instead of burning energy for nothing.
The heat battery decouples heating from load, so the Node can flex with the grid. Aggregated, the fleet behaves as a Virtual Power Plant.
When it stops, it simply stops. No combustion, no emissions on site, no waste heat vented to nowhere.
For the home
96.2%
heat captured
up to 90°C
water output
For the grid
8.3 TWh
wind curtailed, 2024
£393m
paid to switch off
Lower-cost heat and hot water for properties where a heat pump won't fit, won't perform or won't pay, including homes moving away from biomass, oil or gas.
Constant hot-water demand makes shared buildings a natural fit for the same system, scaled to bigger tanks and higher daily use.
Useful heat for rural and commercial sites with space, power and demand, from plant rooms and workshops to growing heat and process heat.
The first installs are underway — we're documenting every step in the Telegram group. Tell us about a building, or come watch it happen.