Large-scale wind and solar power ‘could green the Sahara’

That is the promising headline of a BBC news article. They referred to a paper in Science from the University of Illinois. Lead author Yan Li explains that they modelled what would happen if (really) huge parts of the Sahara desert are covered by renewable energy sources. They calculated that if 9 million km2 of the Sahara is covered, then precipitation would more than double and vegetation cover fraction would increase by about 20%. It has to be of that scale, fewer panels and turbines would have a limited effect.

The researchers focused on this region because it is close to large energy markets in Europe and the Middle East (weird, the journalist forget Africa as a close-by energy market) and they add that such “a massive installation in the desert would generate four times the amount of energy that the world currently uses every year”.

The impact on humans living there would be “mostly positive”: the extra rain will improve agriculture and growth in production of livestock.

Now my head begins to spin. It solves the EU energy transition, optimizes land use, creates more precipitation therefor greening the desert & beneficial for agriculture/livestock and, in one fell swoop, it fixes the climate. Everybody wins.

Not so fast! It seems pretty straight forward to look at the Sahara as a potential energy provider able to deliver plentiful solar and wind power, but it is anything but. There are some things that the journalist is rather silent about.

First, that region is not ours…

The Sahara covers (large parts of) several countries: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, Sudan, Tunisia and Western Sahara. It seems the researchers also included the Sahel, so add Burkina Faso, Djibouti, Eritrea, Ethiopia, Gambia, Mauritania, Niger, Nigeria, Senegal, Somalia and Somaliland.

More, that region is politically rather unstable, there is terrorist activity in the Sahel and the corruption of several of these countries is high. When we take for example the Sahara (which is the largest part of the selected region), then Tunisia has a ranking of 75 in the corruption perception index (the lower the better) and all others occupy places higher than 100. Two of those even rank in the bottom 6. Compare this to Europe: most European countries have a ranking below 30. Even if an agreement could be reached with all/most of those countries, it is not sure that this agreement will be honored in the future. I am not sure whether the Europe/EU/rest of the world wants to be dependable for its energy on a rather unstable region.

I am also not really sure whether the project is economically viable. Filling up 9 million km2 with solar and wind power installations, that is a massive amount of solar panels and windmills (provided that the raw materials are available). Who is going to do those investments? One thing is for sure, it will not be the host countries.

Then there is the issue of infrastructure and maintenance. The Sahara might be “close” to Europe and the Middle East, but it is not that inaccessible. Working in a desert region with sandy soil and shifting dunes will not be an easy task. There will be a need for a good infrastructure to allow for the installation, but also for the cleaning of the panels (with what?), the maintenance of the installations and protecting the installations against the shifting sand (or dig them out from time to time). 9 million km2 of installation will need a massive work force of technicians who need to be living there and will need some level of comfort.

Installation, infrastructure works and maintenance in such a region will be a huge cost. Not only that. Being able to produce four times the energy that the world currently needs is one thing. Harnessing that amount of power is another. Even if it is up and working as it supposed to be, the output will be intermittent. There will probably be a huge surge of solar energy during the day time (of the Sahara region) and this may not always coincide with the demand in other regions. So the European grid needs to be strengthen to allow for such peaks, which is also an extra cost. It is also not possible to rely too much on that power, so a reasonable amount of backup power will be needed that sits idle some of the time. Which is yet an additional economical cost (investments need to be made to install/maintain such power plants but will not be able to pay these off, so subsidies are needed).

I hope the researchers also took all that into account (I do not hold my breath for it).

Then there are some unintentional consequences. The authors state that such a massive installation will not only change precipitation, but will also increase surface temperatures, therefor strengthening the Saharan heat low. Isn’t there the risk that this potentially disturbs weather patterns, also outside the Sahara? I doubt that the influence will only stay within the borders of those countries. This is not one butterfly flapping its wings, this is not even a flock of butterflies flapping their wings, these are massive flocks of giant butterflies flapping their wings.

This seems to be confirmed by the modeled rain impacts graph in the article:

There are the blue areas of the Sahel, but there are also some brown spots (meaning relatively less precipitation) around the Sahara/Sahel region. For example the South of Spain, Northern part of Morocco, Gabon, Congo, Oman, UEA,… There is also the spot near the Horn of Africa that catches my eye. Probably South Sudan and part of Ethiopia? This is a region prone to droughts already, I can imagine that they are not going to be happy when they hear that those installations will give more precipitation in the Sahara/Sahel region, but less precipitation where they live…

Another unintended consequence will be the influence on the current plant and animal life. There might not be many plants and animals in a desert, but these are very specialized creatures, living in a delicate balance with that specific climate. What will happen when surface temperatures and precipitation suddenly increase? What will happen when huge infrastructure works are being done and massive amounts of windmills/solar panels are erected in their habitat? Some species will probably benefit, others not so much. Some even might go extinct if they can’t adapt to the new conditions. Green organizations should be horrified in the face of such an unprecedented disturbance of this habitat.

One can not whack in infrastructure and solar panels/windmills in 75% of the Sahara (and the Sahel) and expect it having no environmental consequences. Okay, you could say that the extinction of some obscure species of desert beetle is well worth it because it is compensated by the clean energy we get in return. But that smells like colonialism. I can vividly image the reaction of social justice warrior types when they hear that Europe/EU is going to exploit the Sahara/Sahel region for their own benefit… That could give some rather interesting discussions to watch 😉

Concluding: the paper is probably some theoretical exercise without a connection to reality. I really start to wonder what the actual goal of that paper is. Could it be this:

“The main message for people, policymakers, and investors is the enormous benefits to the people, society, and ecosystem as a result of these solar and wind farms.”

“We hope that, in the light of our findings, and because of the primary climate effect of these farms is the reduction of anthropogenic greenhouse gas emissions and the resulting mitigation of climate change, we could transform our energy sources. That can lead in turn to sustaining freshwater, food, and life on our planet.”

The paper could well be politically motivated rather than scientific and those “enormous benefits” could only be found when the researchers and journalists frantically avoiding mentioning the disadvantages of these solar and wind farms in the “Sahara”.


9 thoughts on “Large-scale wind and solar power ‘could green the Sahara’

    1. trustyetverify Post author

      That is indeed stiff competition!

      I prefer the Sahara scheme though: no observations and no calculations. The researchers only tweaked a coarse spatial resolution climate model, then ignored any practical issues and declared this the ideal solution for everything.


        1. trustyetverify Post author

          Yes and no.

          The Sahara paper does somewhat apply. It made me laugh and it made me think, that is for sure, but that was not universally true. Many people didn’t laugh, but took it seriously and it certainly didn’t let them think. On the contrary. It confirmed them in their beliefs that building large-scale installations in the desert is a good idea. I don’t think that Ig rewards papers that confirm people in their beliefs, just papers that first make us laugh and then let us think.

          More, it seems at first glance that the authors were less than honest in their paper. Even if we, for the sake of the argument, believe that the outcome of what they modeled is correct, the selection of areas that they called “desert” seems to skew the result towards the current conclusion. But that is probably something for a next post. I still have to gather my thoughts on my hunch and write a coherent post on it.

          Liked by 1 person

  1. 4TimesAYear

    I rather doubt that region is going to want energy competition. There’s also an issue about wind turbine gear boxes and sand/sandstorms. Someone wasn’t thinking clearly when they came up with this. Oh, and a sandstorm could bury solar panels in no time flat. Who is going to clean them off? Sand is heavier than snow and it doesn’t melt.


    1. trustyetverify Post author

      There are systems that could prevent that to some degree (these aren’t run-of-the-mill windmills however, so could come with a price).

      I think the technical stuff will be the least of their problems. There will be a whole bunch of logistical, political, cultural, financial, ecological,… problems to be solved before they come to that and in the end it probably will not be the cheap energy they envision anymore. The authors and the journalist ignored all the potential downsides/issues/problems, allowing them to come to their very optimistic conclusion.

      Liked by 1 person

      1. 4TimesAYear

        There is another issue they raise which I’m rather skeptical of, but let’s say it’s true. Wind turbines double precipitation? If that’s true, then are they responsible for more floods and rain from hurricanes and storms? Just playing the devil’s advocate here.


        1. trustyetverify Post author

          They claim that the precipitation will double when large-scale solar and wind power generation facilities are installed in the Sahara. According to the paper, large-scale means the entire area of the Sahara (= 9.2 million km2) is covered and, even then, the increased precipitation will only be local: the Sahara itself and more pronounced in the Sahel. These are rather dry places in the first place. If we stick to the numbers provided in the graph that was shown in the BBC article, then precipitation would increase in:

          • the Sahara: from 0.24 mm/day to 0.59 mm/day (or 88 mm/year to 215 mm/year): that is more than a doubling, but since it is very dry, even with that doubling it is technically still a desert (less than 250 mm/year).
          • the Sahel: from 2.23 mm/day to 3.57 mm/day (or 814 mm/year to 1303 mm/year): that is from not so dry to rather wet.

          Not sure how or whether this will lead to more hurricanes and storms.

          I think they should worry more about the drying effect in other regions (for example in the Horn of Africa and in Cameroon with 0.5 to 2 mm/day less precipitation). These countries will not be happy to hear that the installations in the Sahara have a drying effect in their region. Also playing advocate of the devil here: can these countries seek compensation for the harm being done on the basis of the outcome of this model?

          Assuming, for the sake of the argument, that their model is correct and at the end of the modeling period of 100 years (so after the installations were replaced at least 4 times by then).

          Liked by 1 person

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