I was wondering whether it’s cheaper to heat a home with a bitcoin miner or a heat pump?
Heat pump 101
The worlds shortest heat pump primer: heat pumps are marvellous inventions!
Slightly longer background on heat pumps: for each 1KW of electricity you feed the heat pump, it magically produces around 3.5KW of heat (resistive heat is 1KW electricity = 1KW of heat). A heat pump, like it’s name implies, moves existing heat. Not dissimilar to how your fridge can extract heat from the inside and emit heat on the outside.
Heat pump do have drawbacks though.
Complexity: moving moving parts, for example the compressor, wear out. Refrigerants leak and need to need regular inspection by specialists.
They only work well in certain temperature ranges: for example an air conditioner (just another type of heat pump) can cool outside air of around 35°C to 24°C indoors (“just” 11°C).
A heat pump working in -10°C outside air temperature to heat domestic hot water up to 60°C (a 70°C delta!) needs to work much harder with lower efficiency. The oft stated 3.5 COP (coefficient of performance) you can think of this as a multiplier becomes a COP of 1.0.
Huge temperature deltas are the reason heat pumps work best when the source of heat is relatively stable. Ground source heat pumps use the earths relatively constant 10°C coupled with a refrigerant optimised for the delta. For reference here are some COP ranges for air, ground and water (think of a long pipe running through a lake) heat sources:
| Typical COP range | |
| Air Source Heat Pump | 2.0 – 4.0 |
| Ground Source Heat Pump | 3.0 – 5.0 |
| Water Source Heat Pump | 4.0 – 6.0 |
Bitcoin Miners
Now let’s think about bitcoin mining as a heat source: each KW of electricity you put into a bitcoin miner is turned into one KW of heat. (and a very small fraction of a bitcoin).
Bitcoin miners are silicon so the only moving part is the fluid circulation system. Typically you would have two loops: the first loop is filled with a dielectric fluid that takes the heat away from the bitcoin miner to a plate heat exchanger. The second loop is a water or glycol loop and would run underfloor (radiant heat loops).
So which one is cheaper to heat? It depends on how much you pay for electricity, the price of bitcoin, and where we are in the bitcoin halving cycle. As of 2024 the return looks something like this:
This shows that bitcoin miners are better heat sources when you pay less than about 15c/KWh.
Here’s my Google Sheet of Bitcoin Mining vs Heat Pumps calculation. I’d be happy to receive any feedback. What this doesn’t control for though:
- outside temperature: air source heat pumps loose efficiency as it gets colder.
- cost of capital: these calculations assume the latest ASIC with a good efficiency. Block is working on a 3nm design which will be more efficient than the current 5nm offerings.
- bitcoin network size: as the network grows, our percentage shrinks and so does the reward
Should Anyone Ask 
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