In Siberia they heat using btc mining: https://archive.curbed.com/2017/11/9/16619032/bitcoin-mining...
This also doesn’t address the wasted materials and labor used to make the chips.
/s
That's not necessarily always the case. There's a threshold where the delta between the outside ambient temperature and desired indoor temperature is too large, it becomes more efficient to use something like resistive heating rather than a heat-pump
(In other places and to a larger extent pop culture, "geothermal" refers to tapping into actual heat sources underground.)
No. The value of a PoW coin is based on the wasted electricity.
If mining does something useful (like heating) for a large fraction of the miners the mining difficulty will go up to adapt to such change, requiring additional mining.
At the end of the amount of wasted electricity will remain the same.
I have a degree in EE.
The wasted electricity is in additional heat that you don't want in your home and you have to vent.
Suppose millions of people could replace resistance heaters with mining rigs that cost exactly the same and consume exactly the same amount of energy every day.
Such people would be running the miners ever if the financial gain is very close to zero, because they were already using the same amount of electricity for heating.
That means they would push the mining difficulty up. But, if the demand for coin remains the same, other people will run mining rigs that releases increasing amount of heat in the environment.
You just pushed the amount of wasted heat from one place to another.
Regarding heating things with electricity, a heat pump is way more efficient than resistance/mining heating because is moving existing heat from one place to another.
The approximation for electrical use in heating is using heaters that can output roughly 10 watts per square foot of your house. 12-13 if your house is poorly insulated.
At full power, that means that a 1,600 sqft house requires 16 kW of electricity. At a cost of 13¢ per kWH, that's about $2.05 for that 16kW of electricity. Of course, no residential house will ever realistically have 16kW available to it, nor would heating ever require a 100% duty cycle. But this is for comparative purposes.
The equivalent amount of gas power would require about 54,000 BTUs from a gas furnace (about 3.4 BTUs per watt). One cubic foot of natural gas provides 1,032 BTUs which means that generating 54,000 BTUs of heat requires about 52 cubic feet of gas (we'll round that up to 65 to account for inefficiencies of a furnace; top end furnaces are in the 80-80% efficiency range). 100 cubic feet of natural gas costs about $0.48, so the cost for natural gas would be around 30¢
Again, neither will (nor could, nor should) run constantly, but it's a sobering comparison.
EDIT: Comparisons were hours vs. seconds; fixed.
They simply periodically pump a bit of heat back out to keep the exchanger free of ice.
You'll periodically need a backup source of heat, but most of the time you'll be fine with the heat pump alone.
Define "cold". Mitsubishi units have 100% of capacity at 23F/-5C and 75% capacity at -13F/-25C:
* https://www.mitsubishicomfort.com/benefits/hyper-heating
They're used in Alaska:
* https://www.nrel.gov/news/features/2021/even-in-frigid-tempe...
Fujitsu says -15F/-25C as well:
* https://www.fujitsugeneral.com/us/residential/technology/xlt...
At the 'break down point' an air source heat pump (HP) is no worse than a baseboard heater: in both cases the COP is basically 1.0. So you might as well go with the HP as it'll be more efficient for probably the majority of the year.
You can get gas furnaces that are 'dual fuel': they'll run the HP refrigerant through the exchange and circulate the conditioned air, and once it's "too cold" switch to gas.
If you're going to buy a only-cooling AC unit, then spending a little more on a heat-cool HP is probably a smart idea. There's a payback period, and it depends on the price of your electricity and fossil fuel (NG, propane).
If you put 1000W of electrical energy into a Bitcoin miner, you get 1000W of heat out the far end. It's the same efficiency as a resistive element space heater, just has done some work (useful or not, it's still work) on the way through.
Same thing for a computer running BOINC or Folding@Home. Power goes in, heat comes out, but you've done something useful in the gap.
I typically heat my office (off grid solar shed) in the winter on waste compute - I've got a few computers in here that run Folding@Home/BOINC and I just run them if I've got surplus power. I have propane backup for the really dark grey days ("generator days" if they extend past about a day - it's cheaper to run a gallon of gas through an old generator than to radically expand my battery bank), but most of my winter heat comes from running F@H/BOINC. To the point that on a clear, sunny winter day, I have my window open and fans sucking cold air in or I'll roast in here. I can hold about 1.8kW of load no problem on a clear day.
Now that I have solar on the house, I've considered adding an old compute rig or two in there for winter heat. It's less efficient than our heat pump on warm days, but we also get some cold, grey, foggy days in which the heat pump likes to ice up badly. Normally, if the heat pump isn't keeping up with things, the thermostat will call for the backup coils (which are just big resistors) to aid, and they're the same efficiency at turning electricity into heat as a couple computers. Old Xeons aren't amazingly power efficient, but you can also get them for free or nearly so and throw compute at your preferred projects.
One can optimize for a wide variety of things - energy spent, compute performed, Bitcoin mined, minimum cost, etc. It works better, and is a lot more efficient, if you look at everything as a system and integrate it. I don't run BOINC tasks on my homeserver when we're in air conditioning season, but I light up a couple cores of them in the winter.
If you put 1000W into a Bitcoin miner, computer, resistive space heater, etc, you get 1000W thermal out.
If you use that 1000W to turn the compressor in a heat pump, you get far more heat out (3-4x is a reasonable average in a lot of areas), because you're not simply generating heat from the energy - you're using the energy to move heat. A heat pump is an air conditioner in reverse - you cool the outside air and heat the inside air.
A standard CPU dissipates heat as a resistive heater would - you pump 100W into the CPU, you get 100W of heat out. I'm not sure what you're using to claim that a CPU "is literally a heat pump" here - it's not, by any standard definition of a heat pump.
And heat pumps are vastly more efficient than resistive heating (or using the heat from a microchip).
In many places, for every 1W of power a heat pump consumes, it can move 4W or more of heat into the space.
However, you're correct about coils icing up. That impacts some regions more than others. I'm in a fairly dry high desert climate, and our coils don't ice up unless we have fog (at which point, yes, they ice badly). There are defrost cycles that reverse the unit and melt the ice, but it is a problem in climates where it tends very humid in the winter.
However, there are a lot of places where it works fine, and one can always use a dual fuel setup, where a heat pump is used down to whatever temperature it starts having problems, then switch over to something else (gas fired furnaces are the usual backing option) in the extreme cold. You still get the energy savings of the heat pump while it works well, but can keep a house warm down to quite chilly temperatures.
Of course, if it gets really cold, a ground source unit becomes worth looking at (heat exchange with the ground, either via a deep well or a bunch of coils under the yard).