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this post was submitted on 22 Jun 2023
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Waste heat is only about 1/100,000 of the warming we get from burning fossil fuels. It won't really become significant unless we use a nuclear-heavy approach to decarbonization.
thanks for the article. it seems that number only accounts for the heat released during energy generation at the power plant but there is also significant heat waste when it's consumed. AC units, electric heaters, refrigerators, lightbulbs, pumps, basically all other machines. an individual unit might not produce that much but there are billions of them.
That doesn't really change the picture much. A typical coal-burning power plant turns about 1/3 of the energy in the coal into electricity. Highly-efficient combined cycle gas turbines might turn 60% of the energy in the gas into electricity. That energy is the amount of waste heat that those devices produce.
turbines are still energy generation, heat is also emitted when that produced electricity is consumed.
all machines have efficiency < 1 and therefore emit heat when used. many of those machines even have the goal of producing/moving heat.
All machines produce heat equal to their energy input. They have an efficiency of 1.0 at producing heat. Some will store it in potential energy for some period, but unless that reaction was exothermic, that potential energy will itself be released and fall back to a lower energy level, usually releasing it as heat.
Yes, but the amount of heat they're generating is by definition no more than the amount of energy in the electricity. This caps the total waste heat impact, and means that for fossil-fuel-generated-electricity, their impact on the earth's temperature is almost entirely a result of warming caused by the greenhouse gases emitted.