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Em_Adespoton t1_iuftst4 wrote

Reply to comment by abat6294 in ELI5: I was looking into gravity and energy and discovered why you can't harness energy from gravity. Carry bowling ball up a hill, let it fall from a cliff, the energy doesn't come from gravity, but from you carrying it up the hill, potential energy? I then pictured it as charging aKamehameha? ELI5 by Comprehensive_Tap131

His point is that the energy doesn’t come from gravitational force, but from (in that case) solar energy, as the water was lifted out of the ocean and dumped on mountains via solar thermal energy. Gravity is zero-sum.

However, this still misses the point that ALL energy is zero-sum — energy cannot be created or destroyed, only transformed. Once deposited on a mountain, gravitational force overcomes solar energy so the energy used to spin a turbine is stored as potential energy, to be released as kinetic energy when the snow later melts and flows through the turbine.

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abat6294 t1_iuftxkh wrote

Oh, well right, he's just stating one example of the conservation of energy.

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Comprehensive_Tap131 OP t1_iugooq8 wrote

To take advantage of gravity for energy you need to go from am area of high gravitational potential to lower gravitational potential. Do the highest levels of Earth's atmosphere contain enough potential to take advantage of an area of high gravitational potential moving to an area of lower gravitational potential?

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Em_Adespoton t1_iuhw105 wrote

Yes?

We do it constantly.

Remember, energy isn’t created or destroyed, just transferred. Gravity is a great way to transfer it, as are other forces.

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