Comment by ralferoo | Hacker News Reader

Comment by ralferoo | Hacker News Reader

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> only produced when sun shining?- which means the quoted OP is only for a few hours a day?

China has a very large desert region in the northwest that receive a LOT of sun year round, so I'd expect the panels to be producing a decent amount of power throughout most of the day.

The biggest problem is actually distance - even a few years back, I was reading that there was a massive amount of solar power, but a very significant percentage was lost in transmission to the most densely populated areas of China which are predominantly in the southeast and east of the country.

These areas are also where a lot of rare earth metals are mined, so feasibly it would be relatively cheap to produce giga-batteries there too smooth demand, but I also suspect that they could see significant advantage to doing things that are traditionally energy-costly like electrolysis of water to create hydrogen that could be transferred across the country by pipe with pretty minimal losses and then burned to drive turbines at the other end. Such systems might end up with overall fewer losses than just having thousands of miles of power grid.

Another thing I read recently that was interesting is that it's getting approximately close to free for China to produce solar panels now, significantly cheaper than anywhere else in the world. Largely this is also due to the excess power produced in the northwest that can be cheaply used in the processing needed to produce more solar panels.

I dunno about that distance problem?

There's a project here in Australia that reckons its profitable to build a solar farm in Australia and ship the electricity over 5,000km to Singapore.

https://www.suncable.energy/our-projects

Maybe that's all just marketing hype and greenwashing corporate bullshit, but it at least _seems_ feasible to transport solar (and battery stored for 24x7) power long distances.

That's where Australia is going to want to be. Perfect for solar. Vast quantities of low population density land with virtually perfect solar weather, and relatively near the equator.

The only issue is that, like the Sahara, but unlike the Arabian peninsula and the American Southwest, Australia is not closely located to any other major consumers of power, so will need to build that kind of infrastructure.

To be honest I'm quite excited. I think the transition to solar is happening faster and at an accelerating rate, ahead of anything we dreamed of even a decade ago.

> The only issue is that, like the Sahara, but unlike the Arabian peninsula and the American Southwest, Australia is not closely located to any other major consumers of power, so will need to build that kind of infrastructure.

Not that I'm an expert of anything but Australia has a lot of mining of resources that I would think could use a lot of electricity? Like instead of sending iron ore to mainland China, why not make steel in Australia if electricity is cheap?

Mining uses "a lot of power" in the sense that it uses several hundred times more power than a typical home. It doesn't use "a lot of power" when you start comparing it to cities with millions of homes and businesses.

I don't have a feel for the numbers, but does that hold true for aluminium and Australian bauxite exports?

Hmmm now I'm curious - google google google.

Refining bauxite into aluminium increases the price about 12 times from $40/ton for bauxite to about $2,700 per tone for aluminium which requires 5 tons of bauxite as an input.

Australia exports about 40,000kt of bauxite a year. It requires about 15 kWh/kg to refine aluminium from bauxite.

So if we refined all that bauxite into aluminium before exporting it, we'd use about 600GWh of electricity to turn $1.6 billion worth of bauxite into $220 billion worth of aluminium. (And the economics is better than that, because there's only be 8 million tons or stuff to export instead of 40 million tons.)

Surely that extra 218 billion a year would be way better (for Australia) staying in our economy instead of having all that bauxite refined somewhere else?

On the other hand...

Sun Cable reckons it'll deliver 1.7GW to Singapore 24x7, or 15,000GWh. So refining _all_ the bauxite would only use 4% of that.

Australia generates about 280TWh of electricity over a year. So refining _all_ the bauxite would use only 0.2% of that.

So no. It sure as hell doesn't use "a lot of power", even if people do refer to aluminium as "solid electricity"...

That was a fun rabbit hole.

(Disclaimer: no effort made to verify numbers some of which were sourced directly from DuckDuckGo search response page snippets. Also, I'm notorious for dropping three orders of magnitude when doing mental math using kilo/mega/giga/tera prefixes.)

Right, so it makes sense to use solar to smelt aluminum, but even if you smelt all the aluminum with solar you'd still need to transmit a ton of power from the isolated desert to the cities where people live.

It's the thing where the use of electricity is a large part of the production of aluminum, but the production of aluminum is not a large part of the use of electricity.

There was a plan to make a line to South East Asia and sell power to them but I'm not sure where it's at.

China was investing in UHV lines a few years back to deal with the distance problem. They seem to have a bunch already: https://en.wikipedia.org/wiki/Ultra-high-voltage_electricity...

I’d expect HVDC to deal with power loss well enough. The longest one in China is 3200 km at 1100kv and 12 Gw capacity.

My guess is that the HVDC lines they have isn’t really enough to move all that renewable energy yet, or the strategy might be to build more industry out west closer to solar and wind, although water is then the limited resource.

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