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by Retric
3600 days ago
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Sunlight is still 2 orders of magnitude more important to the global economy. 7.68 billion acres * 100w/m on average is a mind boggling amount of energy. Plants are around 10% efficient at collecting sunlight so we they get 10W * 4046 m / acre * 7.68 billion acted under cultivation = ~310 trillion watts or 2.7 million terrawatt hours per year. Oil is ~1% of that or 20 thousand terrawatt hours per year. https://en.m.wikipedia.org/wiki/World_energy_consumption#/me... |
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http://globalecology.stanford.edu/DGE/Dukes/Dukes_ClimChange...
Yes, there's a lot of sunlight. But consider that 70% of it falls where you cannot walk, unless you carry your own cross, and much the rest of it is called on elsewhere in the ecosystem. That still leaves a great deal available to humans, but an order or two of magnitude less than that 1,000 times more than we need in a year.
Plants are far closer to 1-3% efficient at converting sunlight to stored energy, so you're off by an order of magnitude there.
I've scoped out the biomass equivalent acreage for US petroleum consumption under several scenarios, and it's not pretty. See the table about halfway down this page:
https://www.reddit.com/r/dredmorbius/comments/2cvap7/the_int...
Consider that much the world would like to be at US levels of energy consumption, and the population continues to increase.
If you want to do some useful reading, start going through Vaclav Smil's books. Most ecology texts are also quite useful. Howard and Eugene Odum have written several excellent ones, both general to ecology, and specific to humans and energy.
Keep in mind that energy is among our immediate problems, but is hardly the only one.