Electricity is one of the most inefficient ways to heat a dwelling. I think natural gas is still considered to be several times more efficient but I haven’t looked at it in a few years. Of course if you are also getting benefits from the crypto you mined that will offset the cost.
This depends on what you’re measuring the efficiency with respect to though, right? Cost-wise, yeah, natural gas outperforms electricity everywhere I’m aware of. On a grid powered entirely by renewable energy though, there’s a meaningful sense in which the electrical method is “more efficient”
>Electricity is one of the most inefficient ways to heat a
dwelling.
This is not true. Resistive heating is inefficient indeed but not all forms of conversion of electricity are inefficient. Geothermal pumps are very efficient for instance and use electricity only, they can be assisted directly by solar (PV) too.
Indeed it's waste heat (and not only in the semiconductors, the conductors/wires/traces and the metal in mosfets have minor contributions). The remark was about heating in general, hence the quote.
Resistive Heating is literally the most efficient form of heating where 100% (ie, all of) of the electric watts you put in are turned into thermal energy.
Doesn't mean that the generator on the other end is efficient but that is a separate concern that can benefit from economies of scale (a big gas turbine would be more efficient than a swarm of small gas ovens producing the same energy).
From thermodynamic standpoint every process is 100% efficient. It is a useless metric. Normally we measure desired energy over certain consumed energy. Heat pumps achieve >100% efficiency.
Furthermore, that 100% efficiency of a resistive heater is only true under very specific high school level circumstances. Under no practical circumstances (e.g. source resistance, reactive load) resistive heater is 100% efficient (though it can get close).
From a thermodynamic standpoint, yes, but nobody with an honest face will claim that makes measuring wasted energy as efficiency a bad measurement.
In cases of heating, resistive is 100% efficient as you loose none of the energy put in to waste heat, only effective heat, while a gas oven or heater will loose heat to it's exhaust gases, thereby being less efficient.
I wouldn't say this is "high school level" circumstances. The waste heat in the wires of your house feeding into the heater will also heat up, no?
The only energy lost is outside the system we're trying to measure, hence, not relevant.
I think you are conflating active and reactive loads. Reactive load is basically EM, not heat.
Yes, reactive current is still current and any series active load (wiring) will experience that current and heat up. The reactive load itself is "imaginary".
I'm aware it's EM but I'm pointing out it's dissipated as heat through wire current. I'm aware it's imaginary, doesn't mean it doesn't produce electrical load in the wire.
Besides, for any reasonable heater arrangement, this loss will be negligible compared to any other heating mechanism.
In theory. Remember that the motor of the heat pump isn’t 100% efficient. It’s still an electric motor. That’s is of course offset by it not generating heat but rather transferring it. So say you’re electric motor is 33% efficient. That means you need a 3x multiplier to break even with a resistive load. And the multiplier depends on the temperature difference between inside and outside. If it’s 70F inside and 50F outside you are golden. If it is -10F outside, you are better off using a resistive load.
I would not call that a 100% efficiency. The efficiency of a heatpump is expressed in Watt per Watt, ie, how many watts of thermal energy are moved per watt of electric energy.
The reason is that simply a heat pump does not convert electrical to thermal energy, so it has no comparable efficiency in that process.
No, Heat Pumps are measured in COP (Coefficient of Performance), not thermodynamic efficiency or "the definition of efficiency for home heating". Which of the 5 definitions do you want to use?
Heat pumps move heat around, that has to come from somewhere. Their performance is not measured in efficiency but the performance coefficient, which simply measures in Watt per Watt how much energy is moved.
Due to heat pump inefficiencies, they only make sense if you can get like a 3-4x multiplier out of them. Beyond that you break even energy-wise. Basically if it’s -10F outside, your heat pump isn’t going to be cheaper than a resistive heater. On the other hand when it’s 50F outside you do better than 4X.
The point is that I can heat my home by 10 degrees with a heat pump using less energy than electric resistive heating, except in specific conditions where it is too cold outside for the heat pump to function well. When I run my auxiliary heat (electric resistive heating), my bill skyrockets.
Where I lived until like a year ago, it was cheaper to heat via electric heating than the heatpump by about 3-4%, the maintenance costs of the heatpump compressor did the rest after a decade. That is in a temperate region with winter not going below -10 or so.
It isn't good for all regions. Just like swamp coolers aren't good for all regions. But the point is that "resistive heating is the best you can do if you want to heat your home" is just plain wrong.
A gas oven is not 100% efficient. If yours says it is, it's a lie sold to you by gas oven manufacturers. It's 100% efficient compared to some previous oven sold.
Simple proof by example; if the exhaust air of your gas oven is warmer than ambient energy, it cannot be 100% efficient. (A few other laws of thermodynamics also play in here)
A gas turbine has the advantage that it can use higher temperature gradients within, as well as high speeds and other mechanisms to take advantage of larger burnoffs of gas.
A gas turbine is 60% efficient at base load and largely will be able to maintain 60% efficiency while being maintained at this load. A gas oven has a rough efficiency of around 70-90 % in AFUE. AFUE does not measure actual thermal efficiency, you can usually subtract between 10-35% depending on your boiler system, which ends you between... 40-60% just like a gas turbine in a worst case. The better cases of 60-80% are unlikely to be a steady state efficiency and more likely to be achieved if you have a boiler with great heat capacity that can hold onto the heat for longer. The efficiency here is ruined by ignition each time the furnace has to start running.
Turns out you can't cheat thermodynamics, but you can certainly market like you did.
Electricity is 100% efficient in a resistance heater, in that all the electricity used is turned to heat. However, it is considerably more expensive per unit heat than natural gas, even though you may only get 70-90% efficiency with your boiler or furnace. A heat pump can be even more efficient, though. An electric heat pump can be more than 100% efficient, in that each watt of electricity can be used to move more than 1 watt of heat into your home using the heat pump.
If electricity is made combusting fossil fuels at a power plant at say 40-50% effciency thats the problem.
If your using fossil fuels for heat its more efficient to burn them directly at point needed and capture the heat, rather than use the heat to convert to mechanical then electrical then back into heat.
Air source heat pumps are basically solar assisted, they move heat from outside air into heated space using electricity which also contributes resistive heat in compressor friction. The outside air is heated by the sun.
