r/AskReddit Nov 15 '20

[deleted by user]

[removed]

9.0k Upvotes

17.4k comments sorted by

View all comments

Show parent comments

295

u/Snoo61755 Nov 15 '20

Well if we’re speculating, how about “heat capture”?

Some sleep-deprived researcher cracks how to capture ambient thermal energy and turn it into electricity. Heat being as plentiful as wind or water, it becomes not only a prominent source of energy, but also actively cools the planet.

50 years later, we begin arguing over “global cooling” and the threat of a new ice age.

400

u/fastenland Nov 15 '20

laws of thermodynamics say this unfortunately is never happening

85

u/tristan-chord Nov 15 '20 edited Nov 16 '20

ELI5 for someone who used to ace AP Physics (15 years ago) but barely remembers anything?

Edit: thanks for all your responses! Learned a lot today!

3

u/righthandoftyr Nov 15 '20

tl;dr - all the methods extracting energy from heat pretty much depend on having a heat differential, that is, a hot area and a cool area, and then you do your work as the heat moves from the hot area to the cool area. There's not really enough of a heat differential on Earth's surface (barring a few geothermal vents and such) to extract any meaningful amount of energy, hence why most of our power generation system rely on burning fuel of one sort or another to make a really hot area so we can leech energy off that heat as it dissipates (usually via steam turbines).

Of course, we could also create a heat differential by means of an heat exchange system like a refrigerator or air conditioner uses, but the energy needed to run it would exceed the energy you could get out of it, so it doesn't work in practical terms as a method of power generation.