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>The technology now exists to theoretically cover many hundreds of square km of Libya in photovoltaics and take the electricty to Europe It really doesn't. I'm

>The technology now exists to theoretically cover many hundreds of square km of Libya in photovoltaics and take the electricty to Europe It really doesn't. I'm a huge fan of back-of-the-envelope maths, and this idea raises some very fun questions. How big would the power line be, if the UK (where I live) was powered entirely by solar panels in the African desert? The UK's average instantaneous power consumption is around 100GW. Assuming a capacity factor of 5 (which is probably far too low), the power transmission system needs to handle at least 500GW. The current (and somewhat unproven) state of the art in power transmission operates at 1000kv, and can carry 5GW per pylon system. We would need 100 of those operating in parallel. As each of those has a minimum separation corridor of 100 meters, we would need to persuade all of the countries along the route to give us a 4000km x 10km strip of land, as well as the approx. 150sq km of land needed for the panels themselves. This leads to another fun question - if you want to install 150sq. km of solar panels in the desert and still have enough useful life left in the panels when you're done, how wide does the road need to be to carry all of those, and how many trucks will you need working that several thousand km route?

katkatkatkatket 4y ago
I'm out by two orders of magnitude on the amount of desert solar needed to power the UK. It's more like 13000 sq km, comprising approx. 7e9 solar panels. If they weigh 30kg each, and two-trailer road trains are used to transport them, that's 2e5 truck loads. The sheer scale of this logistical problem dwarfs any other feat attempted.
- tuatoru 4y ago
  OK, but that's just an organisation problem. The technology exists.
  - katkatkatkatket 4y ago
    If it's not economically or practically feasible, then no, the technology doesn't exist.
fauigerzigerk 4y ago
We wouldn't want to import all our electricity from one country anyway, even if that country wasn't quite as unstable as Libya. A more realistic option for the UK might be a submarine HVDC link to Morocco, sort of a bigger version of Viking Link project, which connects the UK to Denmark. I'd like to know if the technology exists to imort, say, 5% of our electricity via that route.
- katkatkatkatket 4y ago
  What would be the point? Even getting 5% of our power from desert solar would be astronomically expensive, and a logistical and political problem of historic proportions. All for a tiny fraction of our power usage. Just build nuclear!
geertj 4y ago
Any such system would probably use DC, which would be much more compact than what you describe.
- katkatkatkatket 4y ago
  Find me a comparable DC link (5GW * 100, 3000k+ miles). To overcome I^2 losses, a DC system would need an even higher voltage, and we're already talking about a 1000kv AC system.
philipkglass 4y ago
Electricity consumption in the UK in 2021 was 294.4 TWh: https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu... Annualized, that's an average power of 33.5 GW. On http://gridwatch.templar.co.uk/ http://gridwatch.templar.co.uk/ you can see in the yearly demand view that peak demand for the year was under 40 GW. This initial estimate of 150 km^2 of desert solar farms is too small and your later estimate of 13,000 km^2 is too large. A conservative rule of thumb would be 10 megawatts (real power, annualized) per km^2 of solar farm, which would mean 3,350 km^2 of solar farms for 33,500 average megawatts. Note that solar farm area is larger than solar panel area because solar farms need space between racks of panels.
einpoklum 4y ago
> How big would the power line be The linked blog post explains that it doesn't have to be a power line. You could synthesize LNG and ferry that elsewhere (that is, assuming the techniques described do indeed scale, and you don't have salty water trouble, etc. etc. etc)

katkatkatkatket 4y ago

I'm out by two orders of magnitude on the amount of desert solar needed to power the UK. It's more like 13000 sq km, comprising approx. 7e9 solar panels. If they weigh 30kg each, and two-trailer road trains are used to transport them, that's 2e5 truck loads. The sheer scale of this logistical problem dwarfs any other feat attempted.

tuatoru 4y ago
OK, but that's just an organisation problem. The technology exists.
- katkatkatkatket 4y ago
  If it's not economically or practically feasible, then no, the technology doesn't exist.

fauigerzigerk 4y ago

We wouldn't want to import all our electricity from one country anyway, even if that country wasn't quite as unstable as Libya. A more realistic option for the UK might be a submarine HVDC link to Morocco, sort of a bigger version of Viking Link project, which connects the UK to Denmark. I'd like to know if the technology exists to imort, say, 5% of our electricity via that route.

katkatkatkatket 4y ago
What would be the point? Even getting 5% of our power from desert solar would be astronomically expensive, and a logistical and political problem of historic proportions. All for a tiny fraction of our power usage. Just build nuclear!

geertj 4y ago

Any such system would probably use DC, which would be much more compact than what you describe.

katkatkatkatket 4y ago
Find me a comparable DC link (5GW * 100, 3000k+ miles). To overcome I^2 losses, a DC system would need an even higher voltage, and we're already talking about a 1000kv AC system.

philipkglass 4y ago

Electricity consumption in the UK in 2021 was 294.4 TWh: https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu... Annualized, that's an average power of 33.5 GW. On http://gridwatch.templar.co.uk/ http://gridwatch.templar.co.uk/ you can see in the yearly demand view that peak demand for the year was under 40 GW. This initial estimate of 150 km^2 of desert solar farms is too small and your later estimate of 13,000 km^2 is too large. A conservative rule of thumb would be 10 megawatts (real power, annualized) per km^2 of solar farm, which would mean 3,350 km^2 of solar farms for 33,500 average megawatts. Note that solar farm area is larger than solar panel area because solar farms need space between racks of panels.

einpoklum 4y ago

> How big would the power line be The linked blog post explains that it doesn't have to be a power line. You could synthesize LNG and ferry that elsewhere (that is, assuming the techniques described do indeed scale, and you don't have salty water trouble, etc. etc. etc)