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Comment by IgorPartola | Hacker News Reader

> So first, if you need to do 'work', then definitely just use electricity directly to do the job, which is much more efficient.

Pardon me but this doesn’t sound right. If you want to generate heat, burning natural gas is going to be a lot more efficient overall than first burning natural gas at a power plant then transmitting electricity to your facility to convert it to heat. Similarly with rotational energy, etc. Your second point stands: if you power your process by solar, wind, or hydro you could get ahead of CO2.

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I may have misused the term 'work' here. I was trying to describe the displacement of an object through the actions of something like a motor. You can achieve that by burning fuels (combustion engine), or steam, or an electric motor. I was trying to allude to the latter being the most efficient.

No I know what you mean by “work”, my degree is in physics. What I think is not clear is what you mean by “efficient”.

Gotcha, I reread what you wrote andit makes more sense to me now.

What are your thoughts on using renewable electricity for heating applications as a way to displace burning of fossil fuels?

I mean obviously if you use something like solar or wind it will not produce CO2 so any CO2 your process extracts will be a net gain. If you use it to make ethanol that then gets burned you’ll just be putting CO2 back into the air. If you make construction bricks with it, you won’t.

Solar can also be used to heat things more directly than first converting to electricity (and taking a big loss on that), but then you really are subject to when the sun shines. But if you put your facility in a desert in Arizona you’ll probably do quite a bit with a set of mirrors used to heat specific objects.

I should have been more specific. I was trying to ask about generating renewable energy and then using that at some other site for heating purposes. What kind of efficiency does electricity to heat get you compared to just burning fossil fuels on site? I am not sure if that is the best way of asking this question.

I am not an expert on this but my understanding is that a fossil file plant wastes something like 60% of its energy as lost heat. There is also transmission losses. Whereas an oil or gas heater can get to like 97% efficiency in heating water when on site. Hell, you could get heat for free by just removing it from the smoke stack of a coal fired power plant.

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