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Chile wants to export solar energy to Asia via 15,000km submarine cable

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Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#112
post #109
post #44

Earlier quoted context omitted.

Wouldn't you be better of having microwave relay satellites than laying wire? Test satellites for space-based solar power (SBSP) are already going into orbit as soon as next year: https://en.wikipedia.org/wiki/Space-based_solar_power#In_the...

The loss on microwave relay is just incredibly high (think >90% power loss), because it goes as distance^2. Also there's physical limits on how tight the resulting beam of energy can be -- it's not a laser beam, it'd be irradiating 100s m^2 if not km^2 with whatever it's peak W/m^2 is. Also it can't be anywhere near a useful radio band, because interference.

The distance^2 applies, but it's most pronounced for isotropic source (i.e. emitting across a sphere). If you create a tight beam (think columnated laser), you vastly reduces the overall system loss. The bigger problem for microwave links is converting electricity to RF & back -- you get big losses in the amplifiers, radiators & rectifiers.

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#113
post #68

I would have assumed corona discharge would be worse in sea-water & made this basically infeasible. The air or sea-water around such high voltage cables gets ionized, even if a strong insulator is used (via quantum tunneling?). I would have thought this effect would be worse in sea-water but perhaps not.

Sea water is highly conductive, with potential close to ground, so the high potential cable cannot be allowed to touch it. So the cable has to be well insulated from the water. Discharge can happen in this insulation, that's why it has to be thick enough.

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#114
post #82

Earlier quoted context omitted.

The whole point is that you can generate the power at different times. The deserts of the middle east get sunlight at a different time then South America. If we had a worldwide spanning power grid we wouldn't need to have a grid storage solution at all.

That's a good point, I can see how this could be better than battery based storage for night time. But I wonder if wind power coupled with some limited battery storage, geo thermal, and newer generation nuclear peaker power plants can solve this problem instead of laying a mega cable under the ocean.

_Microft linked to a great paper saying that 99.99% reliability can be achieved in 42 different countries using a mix of overprovisioned solar, wind and 3 hours worth of batteries.

https://www.nature.com/articles/s41467-021-26355-z

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#115
post #55

Casey Handmer calculated that it was cheaper to produce solar power in Boston for local use than it was to ship solar power from Arizona to Boston.[1] Solar power is 3X as expensive to produce in Boston, but HVDC lines are even more expensive. If it's uneconomical to ship from Arizona to Boston, then Chile to Asia seems even more problematic. Although in this case the submarine HVDC line is competing against batterie…

I think the chile to asia is going to be cheaper than AZ to Boston because there is just ocean between chile and asia. It will be much more expensive over land and dealing with all the things in the way (roads, houses, railroads, tunnels, mountains...).

One option would be to go along the shoreline of the Gulf of Mexico and across Florida, then up along the coast.

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#116

Casey Handmer calculated that it was cheaper to produce solar power in Boston for local use than it was to ship solar power from Arizona to Boston.[1] Solar power is 3X as expensive to produce in Boston, but HVDC lines are even more expensive. If it's uneconomical to ship from Arizona to Boston, then Chile to Asia seems even more problematic. Although in this case the submarine HVDC line is competing against batterie…

Source for cost is this document published in 2014 https://iea-etsap.org/E-TechDS/PDF/E12_el-t&d_KV_Apr2014_GSO... I have no idea whether those are still reasonable estimates, just wanted to point to a possibility of price improvement.

It appears that Casey's source is this $40/MWh project being built by 8 Minute Energy, so he has 2020 numbers.

https://www.energy-storage.news/news/developer-8minute-says-...

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#117
post #10

What percentage of power is lost to line-loss at those distances? And if you are going to cover long distances you usually push up to 750kV or more: how long before there's an insulation breakdown somewhere along your 15,000km and you get some very energetic arcing and sparking underwater? Not to mention that it makes for an interesting asset to target (though only a few nations have the "tools" to attack power cable…

One challenge will be to get enough supply of submarine power cable to make this a reality. The Morocco-UK proposal (mentioned in the bottom of the article) involves the UK company literally setting up a new factory specifically to produce more cable, doubling the global output in the process. And that project is about 4000kms or so compared to 15,000 for this one. So supply will be slow to spin up to those levels.

Well, luckily Chile is the largest copper producer in the world

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#118
post #69

Earlier quoted context omitted.

For one, the power cables seem to be thicker and better shielded than the fiber optic ones. That aside, I don’t think any economy will rely purely on imported power - backups in the form of natural gas plants or grid scale storage will likely need to form part of the mix - there’s already the chance of some cloudy or rainy days over the solar farms, so it’s unlikely there isn’t a contingency.

What you say makes sense to me. OTOH, I get the impression that some of our infrastructure has a financial incentive to eliminate any reserve capacity. E.g., that snowstorm in Texas last(?) winter. So I'm curious if having any non-trivial amount of electricity supplied by a usually-reliable mechanism becomes a long-term risk.

There's actually some automatic de-risking with renewables because of their semi-unpredictable nature. If you have a coal, gas or nuclear plant that runs reliably, some executive will get a bonus if they cut costs by shutting off all the redundancies.

If you cost-cut redundancies with renewables, though, you'll hit a cloudy or non-windy day before bonus time comes around, and then you'll have a new executive who gets a bonus if they have reasonable redundancies.

So there's some resiliency that comes from intermittent renewables, like having a chaos monkey always running on the grid.

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#119

I'm curious about this from a security perspective. With oil, coal, and natural gas, a cut in the supply network doesn't necessarily have an immediate impact. Buffers exist in some parts of the distribution network: ships holds, rail cars, and storage tanks. With electricity, it doesn't seem like we have much infrastructure for buffering the supply. So cutting those cables might have an immediate and significant impa…

Pretty much, destroying pipelines on sovereign soil vs destroying infra in international waters are different risk exposures. Especially one that crosses multiple jurisdictions.

Re: Chile wants to export solar energy to Asia via 15,000km submarine cable

#120
post #70

Why not turn it into microwaves and bounce it via mirrors in orbit? Those cables are super expensive and there is a current shortage of cable manufacturing capacity globally.

The power loss when talking about cables is considered to be quite a bit at about 50% from napkin calculations. The power loss of beamed microwaves is a bit more. https://doi.org/10.1016/j.egyr.2020.12.026 > Finally, the simulation of the long-distance high-power MWPT system can achieve 8.5 kW DC power with about 1% DC–DC transmission efficiency at the operating 2.45 GHz frequency and the 10 km distance away.

For sure, significant power loss. However, given the unavailability of submarine power cable manufacturing capacity [1], perhaps something is better than nothing?

[1] Xlinks has to manufacture its own cables, each 3,800km for this project due to insufficient global production capacity. https://xlinks.co/morocco-uk-power-project/

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