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Comment by lupire | Hacker News Reader

What is the $ cost of the power?

About $20-25/month.

But it's not as if the cost of power is wasted. It's generating heat which I desire. If my GPU is consuming 300W, then that's 300W of heat that my heater doesn't have to generate.

Electric resistive heating is the worst form of heating, though - heat pumps are something like 3-4x the heat per kwh used. So not totally wasted, but a much worse way to get heat into your house, if that's your goal.

Fair enough, but my goal isn't to heat my whole house, just add a little bit to this one room.

My whole house is heated with gas anyways, which AFAIK is more efficient than a heat pump, or at least, is more cost-effective.

Cost effective yes, efficient no.

The efficiency of a heat pump heating a home depends on the temperature outside of the home. I imagine a gas furnace is far more reliable and efficient during times when the outside temperatures are near or below freezing.

I'm stull struggling to understand this concept can someone explain further

Think of the way your fridge works, but your house is the outside of the fridge and the ground is the inside of the fridge. That is, the heat pump uses electrical energy to move heat from the ground (more specifically a deep hole that is drilled) into your house. It takes less than 1J of electric energy to move 1J of heat, therefore one can claim an efficiency >100%.

Think of an inside-out refrigerator.

A fridge moves a certain amount of heat energy from the inside to the outside, but that doesn't come for free. You have to put extra energy into the system to make that happen. The hot side of the fridge gets the "moved" heat plus the heat from the work you had to do to move the heat. The work heat is waste.

If what you're trying to do is make something hot, you're moving heat energy from the outside to where you want it to be hot. That makes it hotter, but it requires work. In this case, since you want to make things hot anyway, that work heat is extra bonus heat.

Say you have a 1kWh budget of energy to spend to heat a room and access to a variety of heating methods such as an air pump and an electric resistor (space heater or computer). Which one should you choose to maximize increase in warmth? While the electric resistor will convert the energy it uses to heat with a very high efficiency, the air pump will usually heat the room even more because it doesn’t just locally convert electricity to heat, it moves heat from outside the room to inside the room. Further info in [1] and [2].

EDIT: great explanation/details in sibling comment by ’prutschman’.

[1] https://www.homecomfortexpertsinc.com/why-are-heat-pumps-mor...

[2] https://www.quora.com/Why-are-heat-pumps-more-efficient-than...

You're still maximizing power generation demand. That makes environmental issues worse even if it does make fiscal sense. You aren't "using power tgat would go to waste anyway".

All power is JIT. It makes a difference.

> You aren't "using power tgat would go to waste anyway".

That's not what I said.

I'm not "using power that would go to waste anyways", I'm generating heat that I would have needed anyways.

In other words, I need to add a little bit of heat to this room. I can either run a small space heater on Low and consume about 300W and get nothing but 300W of heat, or I can mine crypto and consume around 300W, generate the heat I wanted, and earn about $200/month on top of it.

In either case, I'm consuming 300W. I might as well make money in the process.

Is there any cost analyze for using solar panel power for Crypto?

I am installing Solar from Tesla, wonder if I should just use the external power generated for crypto than to send them back to PG&E.

Since you can make money mining crypto paying for power, and the power company pays you less than they charge, or course using it for crypto makes financial sense.

$0.10/kWh @ 300W = $0.1/kWh * 0.3 kW * 720 hrs/mo = $21.60/month

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