Covering the Sahara Desert with Solar Panels to Fight Climate Disaster?
Juan Cole at Informed Comment has a post up by Will de Freitas Should we cover the Sahara Desert with Solar Panels to Fight Climate Disaster?
A map of North Africa is shown, with a surprisingly small box somewhere in Libya or Algeria shaded in. An area of the Sahara this size, the caption will say, could power the entire world through solar energy.
Over the years various different schemes have been proposed for making this idea a reality. Though a company called Desertec caused a splash with some bold ideas a decade ago, it collapsed in 2014 and none of the other proposals to export serious amounts of electricity from the Sahara to Europe and beyond are anywhere close to being realized.
An engineer at Nottingham Trent University has researched various options for Saharan solar, Amin Al-Habaibeh and discusses the sheer size of the Sahara desert and amount of sunshine it receives:
– It’s larger than Brazil, and slightly smaller than the US.
– If every ray of sunshine hitting s the Sahara was converted into energy, the desert would produce enough electricity over any given period to power Europe 7,000 times over.
So even a small chunk of the desert could indeed power much of the world, in theory. But how would this be achieved?
According to Amin Al-Habaibeh, there are two main technologies which can be applied to this project and each has their pros and cons:
– Concentrated solar power using lenses or mirrors to focus the sun’s energy in one spot, which becomes incredibly hot. This heat then generates electricity through a steam turbine.
– A tower in the middle of the mirror or lens is the “receiver” which then feeds heat to a steam generator.
– Some systems store the heat in the form of molten salt. This means they can release energy overnight, when the sun isn’t shining, providing a 24 hour per day supply of electricity.
– Concentrated solar power is very efficient in hot, dry environments, and the steam generators use large amounts of water.
– There are also the regular photovoltaic solar panels which are much more flexible and easier to set up, but less efficient in the very hottest weather.
Amin Al-Habaibeh: “Just a small portion of the Sahara could produce as much energy as the entire continent of Africa does at present. As solar technology improves, things will only get cheaper and more efficient. The Sahara may be inhospitable for most plants and animals, but it could bring sustainable energy to life across North Africa – and beyond.”
The issue may be in how to transmit the energy to other areas? Is it still transmission via immense cables?
The longer we delay, wait, deny, and ignore the issues we produced for climate; the more drastic the action to be taken. There is more to the discussion on producing power from the sun in the desert and worth exploring. In Juan Cole’s post: Should we cover the Sahara Desert with Solar Panels to Fight Climate Disaster? there are other sites identified in which to do similar installations.
There is an emerging technology that blends concentrating solar with photovoltaics, doesn’t consume huge quantities of water and uses devices that will probably approach 50% efficiency. The insolation in the desert is a resource that will ultimately be exploited. But the desert is not a wasteland and care must be taken that it is exploited responsibly. Because the ecosystems are so fragile damage is extremely slow to recover.
mining the needed ores & other materials and manufacturing the panels, not to mention building a solar array in the desert and the transmission lines from it to population centers, will have a pretty big carbon footprint itself, upfront, before one watt of power is generated..
The bulk of the materials required for the manufacture of these arrays is plastic and aluminum. While I realize that these are energy intensive processes, it would seem to me that we already produce a lot of aluminum and plastic the question is what is the best use of these materials? Beer cans and water bottles?
The transmission lines are another issue entirely and again a lot of care and planning would need to go into trying to leave as small a footprint as possible. Something we don’t have a very good track record in. Then there is the question of vulnerability to sabotage in that region. So, lots of practical problems, but the technology is evolving to the point where it is beginning to look attractive and I know that SA is dumping some serious money into the prospect for domestic purposes.
Probably a PA 66 Nylon which is more resistant to heat and is structurally strong over the years. Automotive uses a lot of it. I am going to say about a $1.80 a pound and good to 250 degrees C.
Current designs lean on acrylics which are BPA free polycarbonates. This is necessary because of the imperative of optical transparency. Remember the idea here is to efficiently capture the insolation, the resource and channel it to a small area very thin highly efficient PV device. So, the material that does this job needs to be highly transmissive in all of the wavelengths in the solar spectrum optimally not just the visible since the ultra high efficiency of these devices requires using all of the spectrum.
I was thinking more along the lines of structural support and not so much the lenses which to took for granted.
I’ve been reading a book called The Future of Fusion Energy by Jason Parisi and Justin Ball — as much of it as I can read (about half). They start out as physicists doing the everything-that-exists-everywhere thing with renewable energy like the solar. Then, they work back to how much can practicably be produced.
I have to go back over it and over it but I get the feeling that renewables could not even provide half of what mankind uses today (18 tetrawatts). That’s today. To make an uninformed guess, I would guess that 100 years from now mankind will need five or (more likely) ten times as much — as poor areas (India, Africa, South America, etc.) get rich.
The authors see shifting everything to nuclear fission as the only practical way to go — in purely physics terms …
… China is cultivating coal dependency across the world, even as it seeks to reduce its own emissions, Dana Ullman reports http://click1.crm.foreignpolicy.com/tbwvvgrprwvklllbkbwgjkdrtzkggdpbjblpzjclmmjcm_yqmfvbcvnskgmlmqbmm.html?a=13598&b=Editor%26%2339%3Bs+Picks+OC …
… in practical political terms switching everything to fission now — everything we are doing already switching to fission — and — everything all these poorer areas are going to build now and in the future to fission. Mmm.
Even if we could build enough solar energy in one place, nobody would ever trust their day-to-day power supply to lines that come in through other countries, least of all from other countries.
The authors make reaching fusion power sound like a perfectly doable but endless difficult step by step research job — about as doable as upgrading steam power from just draining mines to reliable transport and manufacturing power which took centuries. Same deal: we know the problems we will face as well as the endless effort it will take to solve them. Nevertheless, they make the perfect point that we have to do it eventually anyway so we should pile on the efforts and the dollars as much as we can now.
The authors estimate there may be 1000 times more uranium then currently discovered just because nobody is breaking their back to look for it. It’s just not that hard to find. Also the oceans can supply all the uranium we ever need — 20% higher cost for electricity, that’s all (if I remember correctly).
Forget breeder reactors. Today’s commercial reactors only use 1% of the uranium. Breeders use all 99% by breaking the remain 99% into two forms. One of the two is plutonium (people will be building nuke bombs in their basements).
There’s no real argument for building out solar power solely in the Sahara. Why not build the power systems closer to where they are used, except perhaps in polar areas that have long seasonal periods with minimum sunlight?
If you assume six hours of sun a day and 15% efficiency, it would take 2.5% of the lower 48 states of the US to power the world. That’s only 78,000 square miles. The US interstate highway system takes 36,000 square miles, so we could find the land, just in the lower 48, to power the entire world. There really isn’t a shortage of land. It’s more about a shortage of will.
Misspelling one word in the last sentence may have caused a misunderstanding. I did mention we could do the same in other parts of the world. The southwest in the US offers much open land and sunlight. Perhaps the right of way on highways could also be used? Yes, you are correct. On Juan Cole’s site there is a map showing potential other places to do similar. I just did not include it here. Indeed a will and a few dollars and we achieve much more power.
My take is that probably the answer will end up being biological collectors in salt water (converting Co2 to O2 as a bi-product). I know a downer for technophiles.
Perhaps, a downer. Less costly, less invasive?
It’s not about generating the energy. It’s about transmission & storage.
In this partial of the entire article at Juan Cole’s site, there is an idea of using molten salt to store energy on a short term basis. Smaller units for homes are using batteries to store energy while the rest goes to the local electrical system. What are your thoughts on this?
Closer to home we should be building PV farms on public and tribal lands adjacent to existing hydro plants in the desert SW. This is an area of high insolation where the transmission lines already exist and the hydro resource is likely to be in decline due to climate change.
Perhaps, perhaps politicians will awaken to the need for it.