5 ms·

Saul Griffith has an old talk entitled "Climate Change Recalculated." The gist is that he converts everyday energy consumption into averaged watts over a day, a

Saul Griffith has an old talk entitled "Climate Change Recalculated." The gist is that he converts everyday energy consumption into averaged watts over a day, and then looks at the energy area density of renewables. The resulting picture is rather daunting. If we go 100% renewable--If we even could!--all of our lifestyles would be radically curtailed, and this is after a construction binge of enormous scale. We absolutely need fission and/or fusion. Of this there is no doubt.

pfdietz 7y ago
Yeah, that's bullshit. Energy density of renewables doesn't preclude current lifestyles. The Earth is constantly hit by 100,000 TW of sunlight, and the energy collected doesn't have to be used near where the collectors are.
- serioussecurity 7y ago
  Density in this case referring to "kW per acre of solar panels", and the #s come out to something like covering all of Australia with solar panels, if I remember correctly.
  - peteretep 7y ago
    > and the #s come out to something like covering all of Australia with solar panels, if I remember correctly You do not remember correctly. Estimates seem to vary, but Musk reckons 100 miles by 100 miles for America[0] which I make as 0.003% of Australia. It's a large (if imaginary) place. [0] https://futurism.com/elon-musk-tells-national-governors-association-how-we-could-power-the-u-s-with-solar https://futurism.com/elon-musk-tells-national-governors-asso...
    - theothermkn 7y ago
      GP remembers correctly. From http://longnow.org/seminars/02009/jan/16/climate-change-recalculated/ http://longnow.org/seminars/02009/jan/16/climate-change-reca... : > In other words, the land area dedicated to renewable energy (”Renewistan”) would occupy a space about the size of Australia to keep the carbon dioxide level at 450 ppm. To get to Hanson’s goal of 350 ppm of carbon dioxide, fossil fuel burning would have to be cut to ZERO, which means another 3 terawatts would have to come from renewables, expanding the size of Renewistan further by 26 percent.
      - pfdietz 7y ago
        That confuses primary energy with zero-entropy energy (work). One does not replace a gigajoule of coal with a gigajoule of electrical energy. It also is talking about biomass, which is very land inefficient. So, basically, the source you are pointing to is obviously flawed and should be ignored.
peteretep 7y ago
This feels like it fails the sniff test for me. The UK is currently getting about 1/3 of its electricity from renewable sources[0]; my understanding is that variability is the reason it's not getting more, and people seem pretty bullish about improvements in battery tech. Does the UK have such unique geography? [0] https://smarterbusiness.co.uk/uk-renewable-energy-percentage-2018/ https://smarterbusiness.co.uk/uk-renewable-energy-percentage...

pfdietz 7y ago

Yeah, that's bullshit. Energy density of renewables doesn't preclude current lifestyles. The Earth is constantly hit by 100,000 TW of sunlight, and the energy collected doesn't have to be used near where the collectors are.

serioussecurity 7y ago
Density in this case referring to "kW per acre of solar panels", and the #s come out to something like covering all of Australia with solar panels, if I remember correctly.
- peteretep 7y ago
  > and the #s come out to something like covering all of Australia with solar panels, if I remember correctly You do not remember correctly. Estimates seem to vary, but Musk reckons 100 miles by 100 miles for America[0] which I make as 0.003% of Australia. It's a large (if imaginary) place. [0] https://futurism.com/elon-musk-tells-national-governors-association-how-we-could-power-the-u-s-with-solar https://futurism.com/elon-musk-tells-national-governors-asso...
  - theothermkn 7y ago
    GP remembers correctly. From http://longnow.org/seminars/02009/jan/16/climate-change-recalculated/ http://longnow.org/seminars/02009/jan/16/climate-change-reca... : > In other words, the land area dedicated to renewable energy (”Renewistan”) would occupy a space about the size of Australia to keep the carbon dioxide level at 450 ppm. To get to Hanson’s goal of 350 ppm of carbon dioxide, fossil fuel burning would have to be cut to ZERO, which means another 3 terawatts would have to come from renewables, expanding the size of Renewistan further by 26 percent.
    - pfdietz 7y ago
      That confuses primary energy with zero-entropy energy (work). One does not replace a gigajoule of coal with a gigajoule of electrical energy. It also is talking about biomass, which is very land inefficient. So, basically, the source you are pointing to is obviously flawed and should be ignored.

peteretep 7y ago

This feels like it fails the sniff test for me. The UK is currently getting about 1/3 of its electricity from renewable sources[0]; my understanding is that variability is the reason it's not getting more, and people seem pretty bullish about improvements in battery tech. Does the UK have such unique geography? [0] https://smarterbusiness.co.uk/uk-renewable-energy-percentage-2018/ https://smarterbusiness.co.uk/uk-renewable-energy-percentage...