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That says global 'consumption' is about 80000 TWh a year. Incoming solar energy is about 1700 times that

IMTDb 5y ago
Wait, does the mean that if we wanted to use solar as an energy source for the world we would need to cover roughly 1/1700 of the entire surface of the planet with perfectly efficient panels and interconnections between the east and the west to support the energy transfer during nighttime ?
- teamonkey 5y ago
  Back of the envelope calculations. 1) Assume a 1x1m solar panel generates 150W at peak. 2) It won't manage that all the time, far from it. Lets say it generates 300Wh per sq. meter. per day, or 110kWh/m^2/year. To achieve 80000TWh we'd need about 730million 1x1m panels. For comparison, google says the land area of New York city is 783million m2.
  - fsh 5y ago
    You are off by a factor 1000. 80 PWh is 730 billion times 110 kWh.
    - teamonkey 5y ago
      Sorry, you're right. You'd need to cover a land area slightly larger than Texas.
      - iso1210 5y ago
        Or much less than the Sahara Desert Of course it's not just solar, throw in geothermal, tidal and wind too
alduin32 5y ago
Wouldn't absorbing 0.06% of the incoming solar energy have a significant impact on the planet's ecosystems, either by the absorbed energy by the massive production of PV and storage required for that end ? I think that your statement does not rebutt the parent comment : producing the energy required to sustain our modern lifestyle and population count will have significant impacts on the ecosystems, whatever the source we use for that energy.
- H8crilA 5y ago
  Minimal effect compared to the greenhouse effect of +2, +3 or even +4C. Like not even close.
- fsh 5y ago
  All generated primary energy will eventually be turned into heat. However, the climate effect of this direct heating is orders of magnitude smaller than the greenhouse effect from burning hydrocarbons.
H8crilA 5y ago
Indeed, there is hope! And note how fast the renewables portion is growing, we're looking at a fairly good projection here: 1, 2, maybe 3 decades ahead of us it should get really substantial. The biggest problem is the EROEI, which is a lot higher for the clean stuff, though still improving.
anamax 5y ago
> That says global 'consumption' is about 80000 TWh a year. Incoming solar energy is about 1700 times that Assuming that you still want oceans to work, about 2/3rds of that is not available, which get us to 500x. You also want land-based plants to work, which gets us to <250x and much of the remainder is unsuitable, so let's call it <100x. "make equipment" through end-use solar is <20%, so we're down to <20x. What else am I missing?

Wait, does the mean that if we wanted to use solar as an energy source for the world we would need to cover roughly 1/1700 of the entire surface of the planet with perfectly efficient panels and interconnections between the east and the west to support the energy transfer during nighttime ?

teamonkey 5y ago
Back of the envelope calculations. 1) Assume a 1x1m solar panel generates 150W at peak. 2) It won't manage that all the time, far from it. Lets say it generates 300Wh per sq. meter. per day, or 110kWh/m^2/year. To achieve 80000TWh we'd need about 730million 1x1m panels. For comparison, google says the land area of New York city is 783million m2.
- fsh 5y ago
  You are off by a factor 1000. 80 PWh is 730 billion times 110 kWh.
  - teamonkey 5y ago
    Sorry, you're right. You'd need to cover a land area slightly larger than Texas.
    - iso1210 5y ago
      Or much less than the Sahara Desert Of course it's not just solar, throw in geothermal, tidal and wind too

alduin32 5y ago

Wouldn't absorbing 0.06% of the incoming solar energy have a significant impact on the planet's ecosystems, either by the absorbed energy by the massive production of PV and storage required for that end ? I think that your statement does not rebutt the parent comment : producing the energy required to sustain our modern lifestyle and population count will have significant impacts on the ecosystems, whatever the source we use for that energy.

H8crilA 5y ago
Minimal effect compared to the greenhouse effect of +2, +3 or even +4C. Like not even close.
fsh 5y ago
All generated primary energy will eventually be turned into heat. However, the climate effect of this direct heating is orders of magnitude smaller than the greenhouse effect from burning hydrocarbons.

H8crilA 5y ago

Indeed, there is hope! And note how fast the renewables portion is growing, we're looking at a fairly good projection here: 1, 2, maybe 3 decades ahead of us it should get really substantial. The biggest problem is the EROEI, which is a lot higher for the clean stuff, though still improving.

anamax 5y ago

> That says global 'consumption' is about 80000 TWh a year. Incoming solar energy is about 1700 times that Assuming that you still want oceans to work, about 2/3rds of that is not available, which get us to 500x. You also want land-based plants to work, which gets us to <250x and much of the remainder is unsuitable, so let's call it <100x. "make equipment" through end-use solar is <20%, so we're down to <20x. What else am I missing?