Not really. Heat pumps can't be used in cold climates due to ice forming on heat fins which breaks the efficiency. It's why we use a lot of baseboard heaters in Canada. Bitcoin mining would be perfect for electric heating of homes here. Plus the added bonus of eliminating green house gas emissions from burning natural gas in a furnace (how my house is heated). The problem with baseboard is that gas heating is far cheaper than electric. So could Bitcoin actually be used to make the world greener?
> So could Bitcoin actually be used to make the world greener?
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 think you need to research more. A computer is actually a heater that is 100% efficient. If you actually "waste electricity" to do useless computation, you still get 100% efficient heat output. 1000W of electricity pumped through your cpu is outputting 1000W of heat as well. Maybe imagine if your logic gates in your computer is water powered. You could still drink the water after it did it's computation.
If running a Bitcoin heater costs half as much as running a regular Bitcoin miner then you can spend the savings on twice as many miners to get more Bitcoin. If everyone does then the effect is net zero. However, your miner can't be a heat pump so in practice it would be net negative.
Yes so now 20 million people (very small amount) install these space heaters, heck install 3. Now they are at equilibrium except the mining difficulty has gone wayyy up (because 20 million ASIC miners will double the global hashrate approximately). Now mining in server racks is no longer profitable because dealing with waste heat is a major expense for them. So not only is hashing now very distributed, but also not 100% wasted.
> I think you need to research more. A computer is actually a heater that is 100% efficient.
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.
Ah I see what you meant by "work can't be useful", apologies. But I think you did jump to some conclusions for example, increase of difficulty does not require more miners. It is a side effect of miners joining. So the profitability of existing mining infra in server racks will go down due to the difficulty increase. It would most likely incentivize them to also somehow recycle their "waste heat" for profit. My comment elsewhere is maybe devoping space heaters that do computation (maybe hashing is not that computation but I think it can work), we could use them to migrate off existing heating tech used in my country (natural gas furnaces) and net lower greenhouse gas emissions because not all electricity is generated from greenhouse gas, only some, and it also has a path forward to no green house gas emissions from electricity generation.
I guess I was trying to say its efficiency breaks down and isn't competitive with basic electric baseboard heat at some temperature below zero celcius (not sure what the break-even point is). I didn't think people in Alaska would be using that for home heating, is that a thing? The norm here is gas heat and the odd electric baseboard home which broken down elsewhere by another commenter is approximately 10x the price of gas heating.
> I guess I was trying to say its efficiency breaks down and isn't competitive with basic electric baseboard heat at some temperature below zero celcius (not sure what the break-even point is).
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).
That sounds really interesting but isn't that useless because at that point you may as well use geothermal. Doesn't the exchanger need air to flow over it hence the fins for it to work? I think geothermal is the biggest win environmentally however so there is that.
In most places, "geothermal" is just a "ground sourced heat pump". Circulate a liquid underground so that it keeps that 50-degree temperature, run a heat exchange with that as the source instead of the air.
(In other places and to a larger extent pop culture, "geothermal" refers to tapping into actual heat sources underground.)
For those of us living on boats (in the UK, so nothing close to Siberia temperatures) how feasible is solar powered off grid mining, using heat for hot water/heating?
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.
> Unfortunately it’s still way, way less efficient than other heating systems like heat pumps
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
For about the zillionth time, space heating with Bitcoin mining is about one-quarter as energy-efficient as using an actual heat pump and so the “we can heat buildings with it!” argument does not actually excuse the massive energy use at all.
I commented above but from my understanding heat pumps are worse than baseboard electric heaters when the temperature outside is below zero celsius (assume the air is exchanged outside) because the fins start to ice over due to condensation and it's why no heat pumps are used in so many countries that are cold. But I have only researched a bit would appreciate any expert opinions!
The 0C limit was true in the 80s, but isn't nearly as true now. My unit, which is far from a top of the line heat pump, holds a COP >1 down to about -15F, or -26C.
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).
A "heat pump" in this context is a device that uses a refrigeration cycle to extract heat from outside and move it inside. An A/C running in reverse, essentially.
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.
The metric being discussed relates to how much thermal energy you get for a given electrical input.
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.
Bitcoins use an entropy increasing resistance hash function, which makes it terrible for heating and cooling. There's a reason why we should use FedCoin instead of Bitcoin or cash or gold.
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 knew someone last winter, during the spike in Bitcoin prices, who had done the math and figured out that heating on some older Bitcoin miners was profitable. Not only was the value of Bitcoin produced greater than his power cost (not everyone has CA power costs), it meant he wasn't paying anything separately for heat. I think he got them for very little because they "weren't profitable to run" when they were being sold.
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.
Well sure if you happen to live somewhere that has 100% carbon neutral electricity - but in that (very rare) case the electricity use for mining Bitcoin without heating your house is also not an environmental problem. In reality, the vast majority of Russian electricity comes from fossil fuels.
Turning gas into heat is very efficient. Turning gas into electricity and then into heat is not. Winter heating with renewables is problematic. You need to meet very strict insulation standards for it to be viable.
This also doesn’t address the wasted materials and labor used to make the chips.