How Africa's desert sun can bring Europe power
December 13, 2007 6:31 AM   Subscribe

How Africa's desert sun can bring Europe power. A £5bn solar power demonstration project called Desertec is being developed by Trans-Mediterranean Renewable Energy Cooperation (TREC) that would send solar energy northward from African deserts. The goal is in 30 years to provide a significant fraction of Europe's electricity needs.
posted by stbalbach (35 comments total) 3 users marked this as a favorite
 
Related: "Wind 'could power all UK homes'". New UK plan to do massive wind power installation.
posted by stbalbach at 6:32 AM on December 13, 2007


Seems silly for wealthy Europeans to invest in the power of Africa's sunlight when there are many African people waiting to be rounded up, packaged, and sent to various places for the purposes of cheap if not free labor, energy, and power.
posted by billysumday at 6:38 AM on December 13, 2007


Also, wasn't this what the evil powerbroker in Sahara was trying to do?
posted by billysumday at 6:39 AM on December 13, 2007


Finally.
posted by DU at 6:46 AM on December 13, 2007


Seems silly for wealthy Europeans to invest in the power of Africa's sunlight

"A £5bn solar power plan, backed by a Jordanian prince.." (first link, header, top of page).
posted by stbalbach at 6:59 AM on December 13, 2007




Sounds like a boondoggle to me. Solar is cool technology, and it would be great to make use of the desert land. I also like the idea of desalination as a side benefit. However, isn't moving energy over long cable runs pretty inefficient? Seems like a large chunk of that power would be lost to heat or whatever before it ever lit up a single European home. I couldn't tell from the article if that was factored into the costs that are already 2 times what coal costs.
posted by willnot at 7:44 AM on December 13, 2007


Seems like a large chunk of that power would be lost to heat or whatever before it ever lit up a single European home.

You are right, we better keep burning coal.

It seems unlikely to me that they'd literally run enormously extension cords from the African desert out to individual homes in Europe. Wouldn't they connect to the existing grid? And if they are going to do that, can't they do it in Africa? And if they do that, doesn't it just add to whatever electricity is already on the grid?

It's just another source of power plugged into the common pool. And then all the customers just pull from that pool. There's no way to identify if a given electron came from Africa or France (in fact, they didn't come from either--the speed of physical electrons in a wire is on the order of cm/hr, so all the electrons you receive are just from the wires in/near your house.)

The only thing I don't really know about is if Europe's and Africa's grids are connected like that. But in the US, if you put a solar panel on your roof and hook up to the grid the right way, you can send power out if you want, which runs your meter backwards ("net metering"). Seems like this plan would just be a huge version of that.
posted by DU at 7:58 AM on December 13, 2007


However, isn't moving energy over long cable runs pretty inefficient?

And?
posted by panamax at 8:04 AM on December 13, 2007


btw, this is as good a place as any to link to an interesting if superficial technical analysis of "well-to-wheel" efficiencies of electrical vehicles, wikipedia's discussion of the Tesla. Short answer: 87mpg equivalent.
posted by panamax at 8:09 AM on December 13, 2007


Yes, there is power loss due to long transmission distances, but this can be minimized by transmitting at very high voltages, as they do in Quebec to get power generated at James Bay down to the factories in the St. Lawrence valley. I believe they transmit at 750,000 volts or so.
posted by rocket88 at 8:10 AM on December 13, 2007


...if Europe's and Africa's grids are connected like that.

They're not. There have been proposals to lay a massive HVDC cable under the Straight of Gibraltar.
posted by atrazine at 8:12 AM on December 13, 2007


Don't the people in Africa need this energy? Or is this plan predicated on keeping them from ever developing an advanced, industrial infrastructure?
posted by papakwanz at 8:16 AM on December 13, 2007


Gentlemen, we have found our theatre for the next european war!
posted by blue_beetle at 8:21 AM on December 13, 2007


Don't the people in Africa need this energy?

. . . undoubtedly, but it's not like this is going to be taking their sun. . .

Capital investment chases capital returns. The R&D, should it prove successful, will eventually trickle down to make this approach economically feasible for Africans, too.
posted by panamax at 8:31 AM on December 13, 2007


Don't the people in Africa need this energy?

In this plan, the people of Africa get 2/3rds of the generated power and water desalination. The people of Africa couldn't aford to create these plants, so they're trading 1/3 of the generated power to their financiers.

My point about the lost power is it wasn't clear to me if that was factored into the cost per kilowatt estimates from the story. If it's very inefficient, then it naturally follows that it would cost even more than anticipated. If transmitting at higher volts overcomes that, then maybe it isn't such a problem, but it sounded to me like one of those pie in the sky sounds cool, but isn't really practical kinds of solutions.
posted by willnot at 8:31 AM on December 13, 2007


There have been proposals to lay a massive HVDC cable under the Straight of Gibraltar.

Norway and the Netherlands are building an underwater power cable to connect their power grids. 580km under the North Atlantic. Running a cable set from Spain to Morocco to connect European and North Africa grids is no challege at all.

Of course, the flow of energy is more likely to come from Europe TO Africa, but that's just fine. Africans need electricity too.
posted by three blind mice at 8:39 AM on December 13, 2007


And, finally, regarding loss over long distance transmission, its actually reached the point where even the very low temperature superconductor we can build today can, in some circumstances, save more money than the cost of keeping it cool. Here in the USA Detroit is using superconductors to do just that.

Dunno if it'd work for this app, but the point is that shipping electricity over that sort of distance is far from impossible, or even economically impractical. Hell, there's wind farms in the Texas panhandle selling electricity to California, that's a longer distance than across the Med.
posted by sotonohito at 8:53 AM on December 13, 2007


Don't the people in Africa need this energy?

. . . undoubtedly, but it's not like this is going to be taking their sun. . .


I kind of like the image of the evil Europeans stealing the African sunlight, as if it was oil or something. FWIW I'm not sure this scheme sounds all that realisitic, but it's almost certainly less exploitative and destructive than, say, the nigerian oil industry.
posted by Artw at 9:21 AM on December 13, 2007


Have fun paying those transmission build-out costs, Europe.
posted by Pants! at 9:24 AM on December 13, 2007


Hell, there's wind farms in the Texas panhandle selling electricity to California...

Do you have a cite for that? I suspect the wind power is going into the grid and used locally in TX, then green RECs are sold to CA.
posted by SteveInMaine at 9:26 AM on December 13, 2007


FWIW WIkipedia gives 4,000 miles as the longest cost-effective distance for electricity transmission, though I've not read the literature on that. Texas to California is certainly plausible within that.
posted by Artw at 9:37 AM on December 13, 2007


There have been proposals to lay a massive HVDC cable under the Straight of Gibraltar.

There is already a chunky interconnector under the Channel between France and England.
posted by patricio at 9:52 AM on December 13, 2007


SteveInMaine Sorry I don't have a cite. Got the info a year or so ago from a person I know who works as a load balance type for my local coal burning power plant, and he, in turn, got it from a friend of his who has the same job for the wind people. The way he was talking it sounded like actual electricity being shipped, but due to the third hand nature of the info you could well be correct.
posted by sotonohito at 9:55 AM on December 13, 2007


30 billion watts (presumably watt-hours) shipped to Europe in a year.
That's 7 million watts for 12 hours each day for a year.
Transmission losses for HVDC are about 8 percent per 1000 Km.
HVDC transmission lines cost about five hundred thousand dollars/kilometer.

(http://www.worldbank.org/html/fpd/em/transmission/technology_abb.pdf)

Let's do Nevada next. I know of a nice atomic test site that isn't going to be
used for much else ever again.
posted by the Real Dan at 9:57 AM on December 13, 2007


i read somewhere that 60 hertz was optimal for alternating current in order to reduce loss during transmission, but metric-minded folk just had to do it at 50 hertz to make it a round number. WHO'S LAUGHING NOW? GO USA!!!
posted by snofoam at 10:20 AM on December 13, 2007


Have fun paying those transmission build-out costs, Europe.

it's really amazing the amount of capital investments a population can make when it isn't throwing a full fifth of its public spending at war toys.
posted by panamax at 10:50 AM on December 13, 2007


SteveInMaine Sorry I don't have a cite.

No problem. I can't find a cite for my claim, but as I understand it clean generators can sell their power locally for the prevailing rate, then sell the RECs on top of it. Helps to defray costs and encourages development of new green generation.
posted by SteveInMaine at 11:14 AM on December 13, 2007


I knew the Sahara had to be good for something.
posted by grapefruitmoon at 11:33 AM on December 13, 2007


Now if there was some way of converting that sand into photovoltaic cells in-situ, that would be kind of cool.
posted by Artw at 11:39 AM on December 13, 2007


I can imagine them building enormous evil solar panel several zillion miles across throwing the rest of Africa into permanent night.. (er was this done on The Simpsons?)
posted by fearfulsymmetry at 12:23 PM on December 13, 2007


Here is SteveInMaine's cite.

Also, grapefruitmoon, the Sahara is good for it's massive river system.
posted by Pants! at 3:07 PM on December 13, 2007


i read somewhere that 60 hertz was optimal for alternating current in order to reduce loss during transmission, but metric-minded folk just had to do it at 50 hertz to make it a round number. WHO'S LAUGHING NOW? GO USA!!!

That doesn't make much sense. Although the difference between 50Hz and 60Hz seems like it would be pretty minimal, you tend to lose MORE power through a dielectric (insulation) as you increase frequency ... not less. So that would mean that the lowest frequency would be preferable.

Optimally, you'd actually send DC. The reason you don't generally use DC in power transmission is that it's a pain to step the voltage of DC power up and down -- you can't use transformers. (Transformers are the key advantage of AC power.) However, advances in solid-state switching converters, similar to the ones used in your computer's power supply, have made DC voltage conversion practical. Thus, quite a few point-to-point power transmission projects have been set up using high-voltage DC (HVDC) rather than AC.

It also has the plus of letting you transmit power between two grids that have different frequency standards, say 60 and 50Hz, although I don't know if this is being done anywhere. Here in the U.S., there are a few places where low-frequency AC power, down at 25Hz or so, is used for rail traction power, and converted from grid frequencies this way.
posted by Kadin2048 at 5:50 PM on December 13, 2007


why can't africa's desert sun bring africa power?
posted by maus at 7:11 PM on December 13, 2007


RTFA, it will.
posted by parallax7d at 11:44 AM on December 14, 2007


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