14 ms·

I don't think the "usual" patterns of solar will hold in the future. The article's example of a solar farm in the Australian outback, with undersea cables runn

by bjt 5y ago

I don't think the "usual" patterns of solar will hold in the future. The article's example of a solar farm in the Australian outback, with undersea cables running to Singapore, pretty dramatically undercuts your second point.

vitus 5y ago
I was surprised to hear that's economical. Singapore to Darwin is about 2000 miles. For reference, that's comparable to Chicago to LA. That's at least an order of magnitude larger than what I'm used to thinking about for transmission. It turns out that if you want to drive your transmission loss down, you need to run at (substantially) higher voltage. This is predominantly driven by resistive loss because your transmission wires aren't perfect conductors, as well as corona loss which scales with voltage. https://web.archive.org/web/20110604181007/https://www.aep.com/about/transmission/docs/transmission-facts.pdf https://web.archive.org/web/20110604181007/https://www.aep.c... has some stats on stats on line losses. At 765 kV (this is 50x what you'd see on a local transmission line), with the best cited figure (circa 2007) of 0.5% loss per 100 miles, you'd see about 10% loss over 2k miles. That's not great, but it doesn't actually seem horrible -- if you're producing 2x the power you need anyways, then you're still delivering a huge surplus.
- wumpus 5y ago
  China has recent laid a bunch of very long high-voltage DC cables to transport power west to east. None of them are underwater, but it sure seems possible. https://en.wikipedia.org/wiki/List_of_HVDC_projects#Asia https://en.wikipedia.org/wiki/List_of_HVDC_projects#Asia -- and sort by length.
  - akvadrako 5y ago
    It's certainly interesting, especially their 1100 kV lines. But what matters is cost; China is building a lot of new coal capacity so it's not like renewables + HVDC is a slam dunk.
  - vitus 5y ago
    Yeah. China has one comparable line (Xinjiang-Anhui / Zhundong–Wannan) which is 3300km running at 1100kV. I can't find any concrete numbers on line loss there, but I would expect if the voltage is 40-50% higher, keeping all else equal, you'd see a 2x reduction in line loss, so close to 5%. (Of course, this doesn't account for last-mile delivery, or AC/DC conversion losses. But the limiting factor isn't the technology, at this point.)
sesuximo 5y ago
That is at best in research and at worst a moonshot idea. Moving electricity long distance is rarely done today (again, not trying to say it cannot be done... just saying this is not a trivial thing where all we need is better govt cooperation as the article implies)

by bjt 5y ago

vitus 5y ago

I was surprised to hear that's economical. Singapore to Darwin is about 2000 miles. For reference, that's comparable to Chicago to LA. That's at least an order of magnitude larger than what I'm used to thinking about for transmission. It turns out that if you want to drive your transmission loss down, you need to run at (substantially) higher voltage. This is predominantly driven by resistive loss because your transmission wires aren't perfect conductors, as well as corona loss which scales with voltage. https://web.archive.org/web/20110604181007/https://www.aep.com/about/transmission/docs/transmission-facts.pdf https://web.archive.org/web/20110604181007/https://www.aep.c... has some stats on stats on line losses. At 765 kV (this is 50x what you'd see on a local transmission line), with the best cited figure (circa 2007) of 0.5% loss per 100 miles, you'd see about 10% loss over 2k miles. That's not great, but it doesn't actually seem horrible -- if you're producing 2x the power you need anyways, then you're still delivering a huge surplus.

wumpus 5y ago
China has recent laid a bunch of very long high-voltage DC cables to transport power west to east. None of them are underwater, but it sure seems possible. https://en.wikipedia.org/wiki/List_of_HVDC_projects#Asia https://en.wikipedia.org/wiki/List_of_HVDC_projects#Asia -- and sort by length.
- akvadrako 5y ago
  It's certainly interesting, especially their 1100 kV lines. But what matters is cost; China is building a lot of new coal capacity so it's not like renewables + HVDC is a slam dunk.
- vitus 5y ago
  Yeah. China has one comparable line (Xinjiang-Anhui / Zhundong–Wannan) which is 3300km running at 1100kV. I can't find any concrete numbers on line loss there, but I would expect if the voltage is 40-50% higher, keeping all else equal, you'd see a 2x reduction in line loss, so close to 5%. (Of course, this doesn't account for last-mile delivery, or AC/DC conversion losses. But the limiting factor isn't the technology, at this point.)

sesuximo 5y ago

That is at best in research and at worst a moonshot idea. Moving electricity long distance is rarely done today (again, not trying to say it cannot be done... just saying this is not a trivial thing where all we need is better govt cooperation as the article implies)