You can't just put all solar panels in Sahara because of so many more important reasons, mainly energy transportation. Power lines will never be that efficient, and battery storage would be prohibitively expensive (and I am not even sure there would be enough rare metals on earth to build that many batteries).
We worked hand in hand with middle east dictators for centuries now, to get their oil. Oil is interesting because it is cheap to transport (pipelines).
I would be curious to know why no one has ever tried to put large solar power plants in the Sahara desert. Covering large parts of uninhabited land with photovoltaic arrays and transporting the electricity to Europe via power lines and submarine cables seems to me easier than launch massive solar arrays into space and beam down the power. I know that many countries in that area are politically unstable, but I guess it is possible to find at least one of them whose government is able to guarantee the security of the power plants upon payment of royalties.
Also there would be national security concerns. You can't just put all solar panels in Sahara because some local African dictator or strong man can just decide to sabotage or just simply turn off the electricity as a power play. Each country would have to have these panels installed on its own territory to be able to have any sovereignty and not be easily blackmailed. You can't put all your eggs in one basket, especially if the basket is an area of Earth where there is very little law and order and constant revolutions, uprisings, terrorism and general political instability.
>We could provide the world's total energy needs by covering a small portion of the Sahara desert with solar.
The Sahara desert is extremely sandy, and extremely windy, which makes it a pretty terrible, or at least prohibitively-expensive place to build a solar farm.
It is also extremely complicated and extremely expensive to transmit large amounts of power over long distances, particularly across national borders (everyone's on a different AC standard), particularly across many national borders.
Luckily, Sahara also happens to be a somewhat decent place for production of solar energy. The question is, in other words, not if we can, but rather if we want to throw all those resources at such a project. I suspect the most difficult task will be to stabilize the region enough for large infrastructure projects to be viable.
The Sahara thing is ultimately just to illustrate that there's no real limit to solar energy (because the upper commenter claimed that nuclear is the only energy that is practically limitless). But of course in practice you'd do the easy things first - that is, build solar on every rooftop. No country is anywhere close to that.
I guess in the future we'll use imported solar for hard to solve problems, e.g. turn it into hydrogen or synthetic fuels (which also makes the transmission loss problem much smaller), while our electricity needs will be served mostly by local wind and solar.
Much more likely that there will be PV in the desert to produce green ammonia, which can then be shipped. We'll need plenty of that, and it's far easier to do than building a several thousand kilometer transmission line.
Also don't forget: The Sahara is in a worl region where plenty of people don't have an electricity grid yet. So yes, by all means, build solar power there, but a significant share of it needs to be provided to the people living there.
On a smaller scale, putting solar panels in the Sahara Desert and run a big cable to Europe is frequently considered. Being in a desert removes most cloud cover, it's close to Europe, and the area required is miniscule even if you want to provide the entire area of Europe that way.
The only problems are that the day-night cycle still exists and storage is expensive, that it would be a massive capital investment, and that the governments of most countries in the Sahara aren't very stable.
There's no solar energy in the Sahara at night. And then as people mentioned, there is energy lost in transmission through resistance in power lines. There's also the fact that not too many of the world's 8 billion people live within serviceable range of the Sahara, assuming you can get past the geopolitical instability in that region to construct and maintain such things. The solar cells would need constant cleaning from dust storms to keep them running at high efficiency.
No, running solar on rooftops isn't the most practical use either. Depending on latitude, weather, cost of solar installation and battery installation, orientation and layout of roof to the sun, the problems with snow, rain, and hail, the lack of solar at night, the fact that none of this generates enough power for those times when you need it most like in the middle of winter in northern climates, etc. Solar and wind will never meet the growing needs of modern economy. Period. It's a pipe dream.
They are great supplemental sources of electricity. They cannot power a first world economy.
In the short term I'm sure they will install a lot of Chinese solar panels. But longer term it would be cool to build one or more massive solar plants in the Sahara to supply Europe and nearby countries via high voltage cables. You might also be able to re green the land in the shade under them. Just covering half of Niger with panels could potentially power the world.
I've lived in many places (Seattle, Edinburgh) where a solar panel is only useful about 25% of the year due to clouds, or the simple fact of being so far north. We don't all live in Southern California.
The Sahara presents an environment with lots of sunlight, little clouds, and nothing else being developed there. And it doesn't need to be solar panels- solar farms based on collectors reflecting to a central tower are what is being cited in the article. We can't do that in most developed areas, because it takes up a lot of space- deserts are mostly empty, perfect for that.
In short, it would make far more economic sense to build solar panels in the Sahara and lose 50% of the power to transmission loss piping it all to Scotland than it ever would to put the same solar infrastructure into Edinburgh (or many other cities in the world).
One of the difficult problems with extremely large solar projects is the infrastructure to move the power. In a lot of these cases, the space to build solar is large areas of land that no one uses... which means that there's not much infrastructure to build the solar power plants, and then not much infrastructure to move that power back to places where people live.
Yes, there's a lot of land that could be used for solar. Moving the enough power to power all of Spain (or all of Europe) based on solar requires some very impressive transmission lines.
I don't think putting up km2 of solar in the Sahara will solve the problem. You just can't ship electricity that far. We're at the point where we need to build any and all green power supplies as much and as quickly as possible if we want to get past this.
20% of the Sahara is a lot of land. I think solar is a great addition combined with other things. My primary residence is in a rural county with a lot of cattle/range land where solar farms could help greatly with something like a microgrid. At a larger level we need wind, hydro and nuclear as well.
You need access to millions of gallons of water a year to run a huge solar plant like Ivanpah, not to mention there probably aren't a lot of great roads for bringing in materials for heavy construction in the sahara vs the American west where in a days drive you are in the container yards at the Port of Los Angeles, so its not as easy as just plopping solar panels in the middle of the desert all over the world.
There were plans to build huge solar plants in the Sahara desert but all got scrapped partly because of energy storage and transport, and partly because few countries want to depend on energy production in countries with either (looming) civil war or semi-regular terrorist attacks.
It costs a LOT of money to build high voltage transmission lines (AC or DC) to transfer power over long distances. So even if they turned the entire desert into a solar panel, the cost to ship that outside of the region would still be billions.
Ah yes, "just build it in the desert". It's only a matter of:
- Building hectares upon hectares of solar panels in one of the most hostile regions in the world
- Maintaining them because the sand is horribly damaging, and replacing them regularly
- ignore the fact that, in the Sahara, there's multiple wars going on over there and that it would be a prime location for a terrorist attack
- Somehow, also build the infrastructure to transfer that energy through the desert without losing it all as heat. Remember, you've got multiple GW coming out of here. A single 800kV line will not be enough
- have backup power lines in case your inaccessible and hard to repair line breaks.
Man, life as a solar zealot sounds easy, all you have to do is ignore physics and reality.
The other problem with solar in the desert is the panels are black. If you have enough to make a difference in energy production you'll also cause a significant amount of warming.
We worked hand in hand with middle east dictators for centuries now, to get their oil. Oil is interesting because it is cheap to transport (pipelines).
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