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Solar power: Difference between revisions
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# We need to be able to create [[rooftop solar|approximately 375,000 km^2]] of solar panels globally, without exceeding the reserves of any minerals. | # We need to be able to create [[rooftop solar|approximately 375,000 km^2]] of solar panels globally, without exceeding the reserves of any minerals. | ||
# If the solar panels still contain ''some'' scarce minerals, they need to be fully recoverable upon [[solar panel recycling|recycling]]. | # If the solar panels still contain ''some'' scarce minerals, they need to be fully recoverable upon [[solar panel recycling|recycling]]. | ||
# The ''energy payback time''{{x|defined as: {energy needed to | # The ''energy payback time''{{x|defined as: {energy needed to produce the panels, including all their primary materials} divided by {power output of the panels, averaged over the full day-night cycle}. But also, if recyclability is needed as per requirement #2 above, then the energy of recycling ''also'' has to be factored in.}} should be ''significantly shorter'' than the lifespan of the panels. {{x|i.e. for panels with a 30-year lifespan, they should pay back the energy in 4 years or less. Preferable a 1-year payback - which could very well be achieveable. The first solar panels would still have to be manufactured using fossil fuel energy. Eventually after getting the ball rolling, [[solar powered factories]] would be viable.}} | ||
# The solar panels don't have to be particularly efficient. 8% efficiency would probably be good enough. {{x|Today's most popular rooftop solar panels are about 17% efficient but too mineral intensive. Half that efficiency might still be enough to meet energy demand including charging [[electric vehicles]]. If not, then more solar panels would have to be manufactured, which is likely still viable as long as requirements 1,2,3 are met.}} | # The solar panels don't have to be particularly efficient. 8% efficiency would probably be good enough. {{x|Today's most popular rooftop solar panels are about 17% efficient but too mineral intensive. Half that efficiency might still be enough to meet energy demand including charging [[electric vehicles]]. If not, then more solar panels would have to be manufactured, which is likely still viable as long as requirements 1,2,3 are met.}} | ||