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Comment by PetitPrince | Hacker News Reader

I realize I have next to no understanding on how long distance energy transport works.

How does one transport energy over such a long distance ? Wouldn't there be massive loss in form of heat due to the fact that cables are not perfect conductor ? I kinda understand that normal cables goes around this by having high-voltage (and needing a transformer to step down the volage for home usage - much safer!), but I assume this is only good for 100s of km. Does that scale up to thousands of km ? Or do they assume that Australia is so energy rich that it doesn't matter if there are big losses ?

Can we do the same in Europe and put massive solar panels in the desert of North Africa and import the energy northwards ? (I realize this is a super naive approach, and the main problem is energy storage rather than generation)

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The starting point for this is High-voltage direct current (HVDC)

https://en.wikipedia.org/wiki/High-voltage_direct_current

which is not the "regular" AC multiphase power transmission. There are existing HVDC links in Europe to join various unsync'd parts of the European grid and its good for quite long legs between stations (there will be a few between Australia and Singapore).

Yes, there's also an aspect that Northern Australia has so much open space and sunshine that transmission losses can be sustained ans still turn a profit.

Neat, thanks !

Browsing other Wikipedia articles let me know that one of the longest existing HVDC is the Rio Madeira HVDC system[1] at 2375 km, and the longest underwater HDVC is the North Sea Link [2] at 720 km

So while the Singaporian-Australian link still feel monumental it's not as science-fictiony as I initially thought.

[1] https://en.m.wikipedia.org/wiki/Rio_Madeira_HVDC_system

[2] https://en.m.wikipedia.org/wiki/North_Sea_Link

> How does one transport energy over such a long distance ? Wouldn't there be massive loss in form of heat due to the fact that cables are not perfect conductor ?

Losses in power transmission are a function of the current (P = I^2 R; power dissipated = current squared multiplied by cable resistance). Using a thicker cable reduces its resistance, lowering losses. HVDC transmits power at -- as its name implies -- a much higher voltage; increasing the voltage means you need to draw less current in order to consume the same amount of power, lowering losses again.

It's why electrical grid transmission networks within countries run at a couple hundred kV. The UK uses 275kV and 400kV for transmission for example, stepping it down to 33kV and 11kV at substations, before it is finally stepped down to 230V for light commercial and residential consumption.

EDIT: A fantastic demonstration: https://www.youtube.com/watch?v=qjY31x0m3d8

You are describing what happens with thermal losses, which as you say can be addressed by running up the voltage. But corona loss goes entirely at voltage and will come to dominate if you try kicking the voltage too much above current levels.

> Can we do the same in Europe and put massive solar panels in the desert of North Africa and import the energy northwards ?

Yes, they’re actively working on it: https://en.m.wikipedia.org/wiki/Medgrid

Unlike European supergrid there are not many news about this project. And given that last mention was in 2013 and completion date is set for 2020-2025, it looks abandoned.

There's another attempt currently in the works:

https://en.m.wikipedia.org/wiki/Xlinks_Morocco%E2%80%93UK_Po...

Is this really still a thing? There hasn't been any news in many years now.

There is or also was https://en.wikipedia.org/wiki/Desertec

"Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km (620 mi), about 50% less than AC (6.7%) lines at the same voltage." [1]

[1] https://en.wikipedia.org/wiki/High-voltage_direct_current#Ad...

Over such long distance, the issue with AC wouldn't be losses but the absurd capacitance of such a long line. That would basically mean you'd need a compensation station every few 100s of kms, which doesn't work very well when you're in the middle of the sea.

And note this is exponential. 2,000km costs you 3.5% + 3.5% + 3.5% * 3.5%. By the time you're running wires around a planet that really adds up.

Which Northern African country would you pick that is trustworthy enough to have your economy depend on for energy need over the coming decades?

One that they(EU) don't see bombing or invading

One proposal is to link the UK to Morocco, which would supply up to 8% of the UK's electricity consumption with a single project. The site would generate 24/7 clean power by a combination of predictable sunshine, predictable wind patterns, and the remainder by batteries.

From reading about the project, it seems the biggest hurdle by far is getting the lengthy cable built. The project is forced to figure out the manufacturing of it's own cable, as there doesn't seem to be enough global capacity to provide it to them externally.

Morocco? If Europeans can stop for 10 minutes whining about democracy and human rights and take a page from China's playbook we can take Africa back.

Oh Europeans shall 'take Africa back' in your opinion?

Wow ok

The Moore-like downward costs of solar panels and battery backup killed satellite mounted panels, worldwide grids with cables across Pacific and Atlantic oceans, mechanical trackers etc. Seems Singapore is an outlier.

Singapore is really small and mostly already urban. There's some space for roof-mounting panels but otherwise it's really at a premium.

From what I understand Singapore is also connected into a larger Asian grid, albeit mostly running on fossil fuels currently.

So this has extra impact also, as once they unlock Singapore, they could potentially start to push renewables into much more of the grid. So yeah a big deal if they can pull it off, hope they do.

> Can we do the same in Europe and put massive solar panels in the desert of North Africa and import the energy northwards ? (I realize this is a super naive approach, and the main problem is energy storage rather than generation)

A very good video from Real Engineering explains that no, not really: https://www.youtube.com/watch?v=7OpM_zKGE4o&t=1s

You have to go DC for long distance (~lambda/4) power line transmission: the closer you get to that conductor length, the more power will be radiated away.

https://en.wikipedia.org/wiki/Desertec comes to mind.

Higher voltage = longer distance. And it's DC so transformers are not involved. Power electronics is used to step the voltage up/down as needed.

>HVDC transmission lines have losses of about 3.5% per 1,000 kilometers, while HVAC lines have losses of about 6.7% at the same voltage.

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