World energy consumption - Wikipedia
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how much does a solar panel cost - Google Search
157 500 Twh of energy used a year by the world. numbers I have seen are to cut the carbon by 20-30% to stay where we are today.
5kwh panel = ~$25,000
157 500 000 000 000 000 x .3 =472 500 000 000 000 we need to get rid of (472.5 trillion)
I am going to add a safety number here. adding another 30% to what is needed just to cover inefficiency and losses.
472.5 trillion + (.3x472.5trillion) = 614.25 trillion whs of solar panels needed
a typical home system that I can find a price for at the low end is $25,000 for a 5 kwh system, we need 614.25twh
so
614 250 000 000 000 (614.25trillion)/ 5 000 = 122 850 000 000 (122.85 billion) 5kwh systems needed
122 850 000 000 x 25 000 = 3 071 250 000 000 000 dollars (3.07125 quadrillion dollars) and thats just the panels themselves. you can at least add that to itself, or probably double it to take care of everything else that goes with (support structures, labor, engineering, clearing etc etc)
so anywhere from 3 to 9 QUADRILLION dollars. no problem right?
The world's $80 trillion economy - in one chart
uh oh, the world's gdp is only 80 trillion. so the problem (assuming 3 quadrillion) by some quick math is 37.5 times larger than what the world can afford. put another way if all the world did was produce solar panels it would take 38 years to afford all that was needed.
-now some other factors to weigh in which I did not address
-new tech reduces energy requirements, but this is offset and probably worsened by an ever increasing demand on tech
-other green techs will also decrease the load, but if we are jumping on one cause we won't be able to do anything else. maybe there are more efficient means of producing clean energy, but this was the easiest number to source as far as cost. and solar is available everywhere, where wind, and water production are not
-some of the energy produced already in the world is "green" sourced and wouldn't need to be reduced.
How much renewable energy does the world use
*ok just keeping this simple again to save the math, they are saying 25% of energy produced is already green sourced. so just removing 25% from my end number leaves us with only 2.25 Quadrillion dollars of solar panels required. *
-with so much demand and emphasis panels would hopefully get cheaper and more efficient. but supply of the rare earth materials that go into panels would undoubtedly be strained, to say the least.
-forgive the lack of noting the units
-hopefully I got all the numbers right, there are a lot of zeroes floating around so it wouldn't surprise me if my 'back of the napkin' math misplaced one on the way to the key board.