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But maybe we don’t want to pave the Earth with PV panels...
by tomp 8y ago
But maybe we don’t want to pave the Earth with PV panels...
- pfdietz 8y agoThe world is bathed in 100,000 TW of sunlight. Current world primary energy consumption is 20 TW, 1/5000th of that amount. In contrast, 11% of the Earth's land area is under cultivation for crops. Add pastureland and that increases to 37%. Why the outrage over PV land use, when it will be just a pimple on agriculture's land use butt?
- fisherjeff 8y agoWell, taking PV array efficiency and land vs. sea area into account, that’s probably closer to 0.5% of Earth’s land area that would have to be covered with panels. Obviously not a huge amount relative to agricultural land but we’re still probably talking about a butt pimple around the size of California.
- pfdietz 8y agoPrimary energy use, though, is energy content of sources before they go through thermal cycles to get work. So one should also take into account the heat rejected in the latter. Nearly 80% of the energy content of gasoline, for example, goes out the tailpipe and radiator as heat. PV would deliver energy in high quality form, electrical power, not as heat. So less than 20 TW, probably much less, would be needed to be equivalent to today's energy usage (although precisely how much would depend on details.) Energy use will be increasing though, as the world gets wealthier. Still, this will also put pressure on agriculture to increase production, as demand for meat increases. Land constraints in the future will come from that, not from PV.
- ThomPete 8y agoBecause the energy density is extremely low compared to ex nuclear. And that it's not just about land use it's also about rare earth materials, the actual production of that many, the installation and maintanance plus no plans for decommision and it still needs ex coal to back it up because it's unrealiable.
- pfdietz 8y agoSolar doesn't use rare earth elements, although that's a favorite fake talking point of the anti-renewable astroturfers.
- ThomPete 8y agoWhat do you call indium, dysprosium, praseodymium, neodymium and terbium, if not rare earth metals?
- pfdietz 8y agoI call them things that are not used in silicon solar panels. Also, indium is not a rare earth element.
- ThomPete 8y agoSo this is wrong?: https://motherboard.vice.com/en_us/article/a3mavb/we-dont-mine-enough-rare-earth-metals-to-replace-fossil-fuels-with-renewable-energy https://motherboard.vice.com/en_us/article/a3mavb/we-dont-mi...
- pfdietz 8y agoYes, it is wrong. Rare earth elements are not used in solar panels. Understand, there's been this obnoxious effort by anti-renewable propagandists to spread the lie that PV is dirty because of rare earths. Shellenberger was spreading this falsehood. But it has no basis in reality.
- ThomPete 8y agovice is pro renewables, so that make no sense. Can you provide som evidence that rare earth metals are not needed?
- 8y ago