The total area of solar panels it would take to power the world, Europe, and Germany

Probably not desirable due to transmission issues, but eventually we might get close to that with decentralized installations.

What fraction of the world’s total known reserves of rare earths would it take to construct these arrays??

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Well you could put those under the solar panels so probably no additional space… unless you want to get into what might be best real rather than theoretical.

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Also the toxic waste produced…
From an old article:

was curious about how this would compare to nuclear... (I know, apples/oranges) Just looked at the Nuclear Energy Institute's waste info page -- US reactors produce a total of ~5 million lbs of used fuel a year. The article above implies over 10 million lbs per year of toxic waste just from California PV manufacturers.
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I think you misunderstand me. Honestly, I’m just asking. I think it’s a given that we have to rely on renewables.

I was trying to answer the question as to why MacKay suggests Concentrating solar power stations like Stirling Engines over PV cells. Skimming the book he talks elsewhere about covering 5% of the UK in photovoltaics, then notes that it’s 100 times the total amount in the world (presumably, that number is out of date…), so I imagine he’s suggesting Stirling Engines as being more achievable (presumably, there’s a restriction on rare earth minerals?).

http://pv.energytrend.com/research/PV_20120307.html

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I think he was proposing Sterling Engines instead of PVs, because of that.

Hence the lower energy density?

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What they need to do is build an automaton that uses solar heat/energy to make PV panels out of desert sand. Even if they are less efficient, perhaps it can be feasible with respect to economics and natural resources. :smile:

Edit: it could have little companions that search the desert for meteorites to use as a source of odd metals…

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Just some food for thought. If you take the average roof size of a US house and times that by the number of houses in the US, the rough overall area is 26,207 square km.

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That makes a lot of sense. Aluminum film on something like a fiberglass-reinforced glass substrate is pretty simple. The structure underneath is a thing but it should be easy to make the network dual-use. It should be possible to add desalinization to the network, pumping seawater from the coast toward the interior while pumping the concentrated brine back. This would make possible intensive farming and hydroponics around the solar installations. Assuming this happens on a large enough scale that it changes the local climate from 50 C to more livable conditions, it could support populations displaced by sea level rise.

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North Africa is full of very diverse geology with plenty of halite deposits too.

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The Western Sahara is basically the perfect place to build these things - total wasteland with constant sunlight, but the ground is chiefly solid rocks instead of sand so it’d be easier terrain on which to build and maintain vast solar farms.

The real problem would be distribution. Northern Africa isn’t exactly the most convenient spot to pipe electricity outwards from - although, if we’re already willing to build and maintain oil pipelines across large swathes of the world, why not “solar pipelines” instead?

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This is one of those plausible ideas that seems so at first blush. Factor in the energy cost for the resource extraction for that amount of solar cell capacity and energy transportation difficulties and the result gets more complicated.

However, solar power is plausible and can be relatively cheap so long as you produce it locally and distribute the energy locally. Germany has this down and definitely has their head in the right place with respect to energy policy. The US could learn a few things from this example.

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Say you want a solar array as big as South Carolina and everybody shouts you down, but say you want a coal field as big as Wyoming and nobody even blinks.

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Why would you want to compare it to nuclear? Toxicity is one thing, radioactivity at geologic timescales is quite another. And I don’t imagine their total potential damage to human and other species are comparable either.

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Yes, we’ve already strip mined an area as big as Delaware

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Free power–from the SUN!!! I don’t believe it–I just don’t!

plugs ears with fingers

LALALALALAALALALALALALAALA

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I had neither heard nor thought of building solar over canals - but that’s genius. I’d love to see us do this here in Southern California; I haven’t seen the loss-by-evaporation numbers for our aqueducts but I suspect they’re pretty harsh. The DWP already owns the land (or at least the right-of-way), so…

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India got the idea from a California company. A few years ago, SPG Solar created a set of “floatovoltaics” to use at the Far Niente winery. In that area, land is too valuable to give over to arrays, and there are irrigation ponds that evaporate in the Mediterranean climate. So, they created a PV array on floats. Other companies have done it now, too.

India is the only place I know of that has done an installation over canals. Since much of California’s aqueduct system runs through either high chaparral or outright desert and is not enclosed, it really would make sense here as well. I have read that the powers that be were approached with idea, but they snubbed it. I wonder if the continued success of India’s program (watching it as a test case) would give them cause to change their minds.

http://www.forbes.com/sites/williampentland/2011/08/15/napa-winery-pioneers-solar-floatovoltaics/

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Maybe we can get the guys cutting down South American rainforest to put up solar panels as they go?

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Pffft. It was a joke. I got it.