Heat your home with power the grid can't use yet.
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
From surplus power to warm water
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.
Power in
The Node runs on the building's existing electricity supply, drawing hardest when the grid has power it would otherwise pay to waste.
Heat captured
A hydronic cold-plate captures 96.2% of the heat the hardware produces and moves it into a water-tank heat battery.
Warmth on demand
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.
Productive, flexible, harmless
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.
Productive
Every watt does useful work before it warms the tank. The compute pays for itself while it heats — instead of burning energy for nothing.
Flexible
The heat battery decouples heating from load, so the Node can flex with the grid. Aggregated, the fleet behaves as a Virtual Power Plant.
Harmless
When it stops, it simply stops. No combustion, no emissions on site, no waste heat vented to nowhere.
For the home
Product performance
96.2%
heat captured
up to 90°C
water output
For the grid
Why flexible demand matters
8.3 TWh
wind curtailed, 2024
£393m
paid to switch off
From 30p to about 11p per kWh
Nothing changes at your meter — you pay your own supplier, on your own tariff. Two things pull the effective price down: the Node earns from its computing while it heats, and the water tank lets it buy electricity only in the cheap half-hours.
Fixed tariff today
With the Node
Node + smart tariff
Worked example — Southern Scotland (Region N), 7.4kW Node. Offset ≈5.3p per kWh consumed uses the entered difficulty, BTC/GBP and hardware efficiency, a rolling 144-block average value of 3.146 BTC (3.125 BTC subsidy plus transaction fees), and a 2% pool fee. Today's levels use market data checked every 24 hours. Smart rate: 12 months of Octopus Agile prices with 07:00-10:00 and 16:00-19:00 avoided (16.6p/kWh average). Illustrative; excludes hardware purchase, maintenance, downtime and tax.
Four months of field dataWarmth where a heat pump can't go
Homes now
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.
Hotels, multi-flat & district heating next
Constant hot-water demand makes shared buildings a natural fit for the same system, scaled to bigger tanks and higher daily use.
Farms, estates, greenhouses & light industry next
Useful heat for rural and commercial sites with space, power and demand, from plant rooms and workshops to growing heat and process heat.
Mined your heating yet?
The first installs are underway. Tell us about a building and we'll get back to you directly — or follow every step in our Telegram community.