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Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. acc
by fuoqi 11mo ago
Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does not make economic sense compared to other energy sources.
- kragen 11mo agoWhile it's true that a geothermal plant is a limited battery powered by hot rock, that doesn't mean it doesn't make economic sense compared to other energy sources.
- piva00 11mo agoI think OP meant technology for drilling becoming cheaper rather than the near-surface availability of it.
- dns_snek 11mo ago> In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!) Ground-source heat pumps extract about 1000 times more power from ground loops, where does the difference come from?
- bluGill 11mo agoA number of sources. Often the air above - ground source relies on the ground being the average temperature of the year round air once you get deep. They also tend to run in heating mode half the year, and cooling mode the other half.
- kragen 11mo agoGround-source heat pumps are irrelevant to geothermal energy sources, and it's unfortunate that the article mentioned them. Ground-source heat pumps are just storing heat from the air during the summer and retrieving it during the winter.
- adrianN 11mo agoIf it can be used to heat houses in winter it’s not irrelevant.
- kragen 11mo agoInsulation, adobe construction, and vigorous exercise can all "heat houses in winter" in the same way as ground-source heat pumps, but none of them can be meaningfully compared with hydroelectric or nuclear power except in a specific situation. How much insulation is enough to charge your cellphone or run a load of laundry? The question is nonsense.
- adrianN 11mo agoThere are lots of houses getting the majority of their heat from ground source heat pumps. Not so many that are heated with vigorous exercise.
- kragen 11mo agoGround-source heat pumps (with a few exceptions and borderline cases like those mentioned in the article) are not sources of heat, so you can only "get heat from" them in the short term; as with a battery or an interest-free checking account, though you may be able to temporarily run a debit balance, in the long run you can only get out what you put in. This is a fundamental difference from energy sources. Energy storage is an important complement to energy sources, especially renewables, and can substitute for energy sources to a limited extent, but confusing them is a fatal error.
- adrianN 11mo agoGround source heat pumps as used for heating buildings source their energy from the sun and work very well. They are outcompeted by air source heat pumps despite better efficiency because digging is expensive.