4 ms·

It's interesting even "renewable" energy can be a problem at some scale too. For instance, at some scale solar would need to be placed over plants, ergo CO2 pr

It's interesting even "renewable" energy can be a problem at some scale too. For instance, at some scale solar would need to be placed over plants, ergo CO2 problems again. And at some scale (hugeeeee scale), even wind energy disturbs nature's air currents and would likely cause pretty big problems there too.

hutzlibu 10y ago
https://upload.wikimedia.org/wikipedia/commons/e/ed/Fullneed.jpg https://upload.wikimedia.org/wikipedia/commons/e/ed/Fullneed... You see the size of the red squares compared to the size of the dessert?
- randyrand 10y ago
  "At some scale" does not imply "at our current scale." Our current energy use is a fraction of the energy we will be using 500 years from now, which really is not that far off in terms of human history. I would imagine we will be using ~500x in 2516, a doubling every 55 years. All of earths deserts and more would need to be covered, even at 100% solar cell efficiency. edit: global energy use has actually doubled every 20 years recently https://gailtheactuary.files.wordpress.com/2012/03/world-energy-consumption-by-source.png https://gailtheactuary.files.wordpress.com/2012/03/world-ene...
wcoenen 10y ago
There would be trouble even with magical free energy. Before the oil shocks in the seventies, oil production and use was more than doubling every decade. [1] If that kind of energy growth resumed unabated, then in about 200 years we'd be producing about as much power as the Earth receives from the sun. We'd cook in our own waste heat, no CO2 required. https://en.wikipedia.org/wiki/Petroleum_industry#/media/File:World_Oil_Production.png https://en.wikipedia.org/wiki/Petroleum_industry#/media/File...
- randyrand 10y ago
  That's interesting. I wonder how well we can shoot our waste heat into space? E = mc^2, so convert the energy into mass and shoot it into space?
  - wcoenen 10y ago
    In principle heat can be gotten rid of with radiators, like the EATCS[1] on the International Space Station. To maximize the heat radiated away, you'd need radiators with as much surface area as possible with an unobstructed view of the sky (no cloud cover). They'd also need to be as hot as possible, because thermal radiation power rises with the 4th power of absolute temperature There have been attempts to detect such thermal radiation from alien civilizations[2]. [1] https://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro... [2] https://arxiv.org/abs/1408.1134 https://arxiv.org/abs/1408.1134

hutzlibu 10y ago

https://upload.wikimedia.org/wikipedia/commons/e/ed/Fullneed.jpg https://upload.wikimedia.org/wikipedia/commons/e/ed/Fullneed... You see the size of the red squares compared to the size of the dessert?

randyrand 10y ago
"At some scale" does not imply "at our current scale." Our current energy use is a fraction of the energy we will be using 500 years from now, which really is not that far off in terms of human history. I would imagine we will be using ~500x in 2516, a doubling every 55 years. All of earths deserts and more would need to be covered, even at 100% solar cell efficiency. edit: global energy use has actually doubled every 20 years recently https://gailtheactuary.files.wordpress.com/2012/03/world-energy-consumption-by-source.png https://gailtheactuary.files.wordpress.com/2012/03/world-ene...

wcoenen 10y ago

There would be trouble even with magical free energy. Before the oil shocks in the seventies, oil production and use was more than doubling every decade. [1] If that kind of energy growth resumed unabated, then in about 200 years we'd be producing about as much power as the Earth receives from the sun. We'd cook in our own waste heat, no CO2 required. https://en.wikipedia.org/wiki/Petroleum_industry#/media/File:World_Oil_Production.png https://en.wikipedia.org/wiki/Petroleum_industry#/media/File...

randyrand 10y ago
That's interesting. I wonder how well we can shoot our waste heat into space? E = mc^2, so convert the energy into mass and shoot it into space?
- wcoenen 10y ago
  In principle heat can be gotten rid of with radiators, like the EATCS[1] on the International Space Station. To maximize the heat radiated away, you'd need radiators with as much surface area as possible with an unobstructed view of the sky (no cloud cover). They'd also need to be as hot as possible, because thermal radiation power rises with the 4th power of absolute temperature There have been attempts to detect such thermal radiation from alien civilizations[2]. [1] https://en.wikipedia.org/wiki/External_Active_Thermal_Control_System https://en.wikipedia.org/wiki/External_Active_Thermal_Contro... [2] https://arxiv.org/abs/1408.1134 https://arxiv.org/abs/1408.1134