5 ms·

Should we solar panel the Sahara desert?

48 points by e15ctr0n 11y ago

zyxley 11y ago
Solar panels on the sort of scale being discussed here would, once you consider the logistics of maintenance, basically be a small (or large) town that also has a huge number of solar panels. Running a company town devoted to solar panel maintenance in the middle of the Sshara wouldn't be impossible, but it's a lot harder than just plunking down a one-time infrastructure investment.
- collyw 11y ago
  Lets face it, if oil was discovered there, the infrastructure to drill and process it would appear. Is processing solar energy any more difficult?
ars 11y ago
Yes, capture energy there. But don't make electricity, make hydrocarbons using the https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces... Ship water and coal, and return with mixed hydrocarbons, then distribute them all over the world. You thermalize (rather than electrolyze) the water to get hydrogen, then react it with the carbon from the coal. Build a large pipeline to the nearest port to transport the material rather than trucking it. The leftover oxygen can be sold, or more likely just released. Since hydrogen releases much more energy (per atom) than carbon when burned, and since since hydrogen outnumbers the carbon in the final product, this will greatly reduce CO2 emissions, even though it's not completely zero. Capturing heat from the sun is much easier and cheaper than electricity.
- kilroy123 11y ago
  This can't possibly be cost effective or profitable?
  - vox_mollis 11y ago
    OP's point (I'm guessing) is that transmission is the problem with remote generation like this. Production of liquid fuels would probably be better than the enormous cost of building transmission capacity and the associated VAR and resistive losses.
    - eloff 11y ago
      Do you really think it's more expensive, in terms of energy to transport electrons over a wire than liquids over the surface of the earth? I find that hard to believe. Mind you, I haven't done the math.
      - dcarmo 11y ago
        I think OP's point is more about storage than transmission. Yes you can transport electrons over a wire, but that has a cost and then you have a limited reachability. With liquid on the other hand, you can store in massive tanks and transport anywhere in the world to produce energy locally.
      - vox_mollis 11y ago
        Bulk transport over the ocean is extremely cheap, so much so that oil speculators are paying ships to idle in anticipation of price rise. Electrical transmission will lose you anywhere from 1%-1.5% per 100 miles depending on the voltage you step up to. Transmitting from the Sahara to the places where the load is gets you to rather large resistive losses. Also, there are generation losses. A traditional heliostat boiler + turbine will get you about 15-20% effficiency. then you have to shunt the waste heat somewhere in a place with very little fresh water. Oops. PV doesn't get you much better, with about 18% efficiency, but you do solve the need for coolant, at the cost of another problem: Sahara dust on your panels. The OP talks about using the thermal output from heliostats directly, which would probably (like you, I haven't done the math) be more efficient in fuels production than 15-20%, although you do have the coolant problem again. One of us should do the math :) Until then, my intuition is that liquid fuels production from such a remote location would probably be more efficient.
- murbard2 11y ago
  Forget the coal, make methanol from water and co2.
  - civilian 11y ago
    What ars is saying that he wants to take the complex and partially-saturated hydrocarbons in coal and turn them into a hydrogen-satured hydrocarbon. (Most coal has a lot of double-bonds and loops within the carbon, in addition to a hydroxyl groups.) Since energy is released every time you break a bond, you'll have more bonds to break in the end product, but with the same amount of carbon, so you're keeping emissions constant while adding energy. Regardless, it would be interesting to start with CO2 rather than coal. But can it be sucked up from the atmosphere efficiently and in mass quantities?
    - radicalbyte 11y ago
      Well, trees have been doing it for a long time. Where do you think the carbon in the trees comes from? :)
      - baddox 11y ago
        Trees do lots of cool things that we don't know how to do. That's true of biological life in general. Heck, the lightest insulation for outdoor clothing is still feathers.
        murbard2 11y ago
        Aerogel is lighter than feathers and more insulating. There was a kickstarter this year for a jacket using aerogel as an insulator. http://www.orosapparel.com/pages/technology http://www.orosapparel.com/pages/technology
        baddox 11y ago
        True. It's pretty exciting tech, although apparently it's not very comfortable or easy to work into clothing and gear. It seems pretty promising for very extreme conditions though, like climbing Everest.
- maaku 11y ago
  Um, that's just a fancier way of burning coal.
  - ars 11y ago
    No it's not. The majority (by far) of the energy comes from thermalizing the water. The hydrogen-oxygen bond is much stronger than the carbon-oxygen bond and there are many more hydrogen atoms in the final fuel.
    - maaku 11y ago
      Ok, it's a more efficient way of burning coal. You're still CO2-emmision positive.
      - ars 11y ago
        > You're still CO2-emmision positive. And so what? I said that, did you not read what I wrote? I'll quote it for you: "this will greatly reduce CO2 emissions, even though it's not completely zero." > more efficient That is way underestimating it, it's a fraction of the CO2 output of any other fuel. By far most of the energy comes from the sun, only a small amount comes from the coal. And it's pollution free since all the heavy metals in coal are captured at the source. It also fits in well with existing technology since there don't exist any other ways of transporting fuel in bulk except hydrocarbons. There simply doesn't exist any other way of doing it. Have you ever heard the saying "The perfect is the enemy of the good?" Trying to be eliminate CO2 entirely is impossible, if you hold out for that you'll do nothing whatsoever.
lvspiff 11y ago
>> "I think the only reason to pursue [solar panels in the Sahara] would be if it were a stopgap measure in which the long-term goal would be to reduce consumption of energy and to change our lifestyles to be more sustainable, so that subsequent generations don't have to deal with as many problems as we're going to leave them." I hear this logic a lot and disagree. Finding more sensible and environmental ways to produce electricity needs to be the goal because we cannot be more sustainable. Mankind thrives on energy. I think the past 263 years (since Franklin's kite experiment) have shown us electricity is a way of progressing. We need power to run things. Where that power comes from is the difficult part. Unless another form of energy is found that can be used to work everyday devices from phones, to computers, to lights, not sure how we get away from electricity and only continuing to increase its consumption. As for paneling the desert - The massive solar arrays in the Mojave desert outside of Vegas show that the sun can be used effectively, but the cost to produce the materials and impact on desert flora/fauna that go into the arrays are just as bad for the environment. The material cost alone in terms of environmental impact make it a laughable endeavor in terms of "environmental" concern.
- bendykstra 11y ago
  I don't like her analogy in which she compares solar panels to smokestacks. As she points out, smokestacks were not a complete solution to air pollution because they merely moved the problem somewhere else. Solar panels are in no way comparable in that respect. The analogy only works if you consider energy production to be itself a problem.
  - acheron 11y ago
    "The analogy only works if you consider energy production to be itself a problem." Welcome to environmentalism.
  - Edmond 11y ago
    She could simply be trying to say that nothing is ever free. Conservation of energy dictates you need energy to produce energy, no matter the tricks you use to get energy there is always a cost even if it is not immediately apparent.
anindyabd 11y ago
So the technology is already there, but we can't/won't implement this because of politics? What a shame!
- eloff 11y ago
  When there's enough money to be made in it, private industry will just make it happen. We're not quite there yet, but it seems likely to happen as prices for solar keep falling. Politics don't have to enter into it, but government involvement has the potential to speed up the process.
stevefeinstein 11y ago
The Media always seem to frame questions like this wrong. The question to ask is, "Why shouldn't we solar panel the Sahara Desert?" And once that question is answered we get started.
- iSnow 11y ago
  Well, the industry asked the question and then left the DESERTEC consortium.
_ph_ 11y ago
The sahara could be a source of endless solar energy. But for the obvious political and technical considerations Europe probably first should look into installing large solar plants in Spain, Italy and Greece. Not only would it support the economies of those countries, but it would be very easy to connect those solar farms to the European grid. Also it would give a nice daytime distribution of the power as Spain and Greece are at the western and eastern borders of the European Union.
notatoad 11y ago
We should not be covering any wilderness (even a relatively barren wilderness like the Sahara) with solar panels until every inch of roof in the developed world is covered in solar panels. There's a ridiculous amount of flat open surface that is just wasted space right now, and not only is the space going to waste but the energy consumers exist right underneath that wasted roof space.
- AC__ 11y ago
  While I agree with your sentiment the problem is that solar panels in populated urban areas that are perpetually blanketed by geoengeering spraying practices are not going to be nearly as efficient as ones in dedicated remote areas not being sprayed.
  - charlesdenault 11y ago
    Chemtrail citation needed.
    - AC__ 11y ago
      https://www.reddit.com/r/conspiracy/comments/1x6r81/huge_list_of_geoengineering_links_and_evidence/ https://www.reddit.com/r/conspiracy/comments/1x6r81/huge_lis...
      - AC__ 11y ago
        Geoengineering is undeniable don't be ignorant. Either you can't read or you are a shill.
        AC__ 11y ago
        I forgot to tell you to gfy. I will never capitulate.
        AC__ 11y ago
        I forgot to tell you to gfy. I will never capitulate.
charlesdenault 11y ago
A distributed system of solar arrays intelligently placed on top of every building in the world, back-feeding into the grid or powering on-site batteries (Tesla Powerwall, etc.). Or massive array in one geographical region susceptible to natural disasters, politics, or terrorism. I'll take the distributed system.
- pm90 11y ago
  There are benefits to both. You can't use a distributed system for, say, Aluminum smelting, which requires tons of electric power. If the idea suggested in the article is implemented, the Sahara could be turned into a "powerhouse" and an invaluable economic resource to the rest of the world. Integration of this system into the global economy would entail tremendous changes to both the world's interest and understanding of Northern Africa.
abalone 11y ago
What about water usage? At scale, doesn't it take a significant amount of water (for a desert) to clean the dust off the panels?
- jws 11y ago
  Brushes are fine.
zobzu 11y ago
who's going to dust the sand off the panels, with what energy though?
- marshray 11y ago
  Sounds like a do-able job for robots, perhaps evolved from windshield wipers.
graycat 11y ago
What to do with the resulting electric energy? (1) Smelt iron or aluminum? (2) Split H2O into O2 and H2 and use the H2 for fuel. (3) Convert water and coal to gasoline. (4) Desalinate and/or purify water and use the water for humans food and drink, bathing, washing, swimming, lawns, greenhouse agriculture, or just to make the desert bloom? (5) Heat salt to store the energy, and then run water through tubes in the hot salt to generate high pressure steam to drive steam turbines and, then, electric generators and, then, transmit the power across the Mediterranean to Europe and sell it? Uses (1)-(4) have the advantages that get just to use the power while the sun is shining and don't have to store the power for nighttime use or transmit the electric power long distances. Would have to transmit the hydrogen or gasoline for those options. In the words of the skeptical mayor's wife in the movie The Music Man, "I'm reticent. Yes, I'm reticent." Why? The idea is not nearly new. So, I do have to suspect that a good engineering-economic analysis would show that we would need progress in: (1) Keeping desert sand off the solar panels. (2) In case want to use the electric energy to make hydrocarbons, a good source of coal near the desert. (3) Energy storage. (4) Superconductivity for the transmission lines across the Mediterranean. Might be able to pay for it if the world can agree on some huge carbon taxes. Nukes might be be cheaper. Might keep in mind that the spot, wholesale cost of electric power in the US has been under $0.01 per KWH and the full cost, say, ballpark $0.06. So, the cost to a consumer of 10, 12, 22 or so cents per KWH is mostly for distribution, not generation. But the panels in the desert handle only the generation part, do nothing for the short distance distribution costs where the consumers are and make the long distance distribution, e.g., across the Mediterranean, more expensive. Also on the money side, might want to keep in mind that the major oil sources in the Mideast pump oil for less than $1 per barrel. That price is tough to compete with. Right, might be shipping the power to France which is doing quite well with nukes. Then once carbon taxes start to take hold, people might watch 'The Great Global Warming Swindle' at https://www.youtube.com/watch?v=52Mx0_8YEtg https://www.youtube.com/watch?v=52Mx0_8YEtg and discover the evidence that CO2, methane, etc. from human activities has nothing at all to do with the climate or temperature of earth and, instead, changes in those two are driven by changes in the activity level of the sun, the sun spots, the solar wind, the blocking of cosmic rays hitting the atmosphere, the rate of formation of water droplets, the rate of H2O cloud formation, and, thus, the cooling effect of clouds. Then people will object to carbon taxes. Net, it appears that while the Watts of solar energy per 1000 square miles of desert are astoundingly high, for what people in the population centers want in electric power, motor fuel, clean water, etc., that desert solar power is just not very valuable.

48 points by e15ctr0n 11y ago

Solar panels on the sort of scale being discussed here would, once you consider the logistics of maintenance, basically be a small (or large) town that also has a huge number of solar panels. Running a company town devoted to solar panel maintenance in the middle of the Sshara wouldn't be impossible, but it's a lot harder than just plunking down a one-time infrastructure investment.

collyw 11y ago
Lets face it, if oil was discovered there, the infrastructure to drill and process it would appear. Is processing solar energy any more difficult?

ars 11y ago

Yes, capture energy there. But don't make electricity, make hydrocarbons using the https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces... Ship water and coal, and return with mixed hydrocarbons, then distribute them all over the world. You thermalize (rather than electrolyze) the water to get hydrogen, then react it with the carbon from the coal. Build a large pipeline to the nearest port to transport the material rather than trucking it. The leftover oxygen can be sold, or more likely just released. Since hydrogen releases much more energy (per atom) than carbon when burned, and since since hydrogen outnumbers the carbon in the final product, this will greatly reduce CO2 emissions, even though it's not completely zero. Capturing heat from the sun is much easier and cheaper than electricity.

kilroy123 11y ago
This can't possibly be cost effective or profitable?
- vox_mollis 11y ago
  OP's point (I'm guessing) is that transmission is the problem with remote generation like this. Production of liquid fuels would probably be better than the enormous cost of building transmission capacity and the associated VAR and resistive losses.
  - eloff 11y ago
    Do you really think it's more expensive, in terms of energy to transport electrons over a wire than liquids over the surface of the earth? I find that hard to believe. Mind you, I haven't done the math.
    - dcarmo 11y ago
      I think OP's point is more about storage than transmission. Yes you can transport electrons over a wire, but that has a cost and then you have a limited reachability. With liquid on the other hand, you can store in massive tanks and transport anywhere in the world to produce energy locally.
    - vox_mollis 11y ago
      Bulk transport over the ocean is extremely cheap, so much so that oil speculators are paying ships to idle in anticipation of price rise. Electrical transmission will lose you anywhere from 1%-1.5% per 100 miles depending on the voltage you step up to. Transmitting from the Sahara to the places where the load is gets you to rather large resistive losses. Also, there are generation losses. A traditional heliostat boiler + turbine will get you about 15-20% effficiency. then you have to shunt the waste heat somewhere in a place with very little fresh water. Oops. PV doesn't get you much better, with about 18% efficiency, but you do solve the need for coolant, at the cost of another problem: Sahara dust on your panels. The OP talks about using the thermal output from heliostats directly, which would probably (like you, I haven't done the math) be more efficient in fuels production than 15-20%, although you do have the coolant problem again. One of us should do the math :) Until then, my intuition is that liquid fuels production from such a remote location would probably be more efficient.
murbard2 11y ago
Forget the coal, make methanol from water and co2.
- civilian 11y ago
  What ars is saying that he wants to take the complex and partially-saturated hydrocarbons in coal and turn them into a hydrogen-satured hydrocarbon. (Most coal has a lot of double-bonds and loops within the carbon, in addition to a hydroxyl groups.) Since energy is released every time you break a bond, you'll have more bonds to break in the end product, but with the same amount of carbon, so you're keeping emissions constant while adding energy. Regardless, it would be interesting to start with CO2 rather than coal. But can it be sucked up from the atmosphere efficiently and in mass quantities?
  - radicalbyte 11y ago
    Well, trees have been doing it for a long time. Where do you think the carbon in the trees comes from? :)
    - baddox 11y ago
      Trees do lots of cool things that we don't know how to do. That's true of biological life in general. Heck, the lightest insulation for outdoor clothing is still feathers.
      - murbard2 11y ago
        Aerogel is lighter than feathers and more insulating. There was a kickstarter this year for a jacket using aerogel as an insulator. http://www.orosapparel.com/pages/technology http://www.orosapparel.com/pages/technology
        baddox 11y ago
        True. It's pretty exciting tech, although apparently it's not very comfortable or easy to work into clothing and gear. It seems pretty promising for very extreme conditions though, like climbing Everest.
maaku 11y ago
Um, that's just a fancier way of burning coal.
- ars 11y ago
  No it's not. The majority (by far) of the energy comes from thermalizing the water. The hydrogen-oxygen bond is much stronger than the carbon-oxygen bond and there are many more hydrogen atoms in the final fuel.
  - maaku 11y ago
    Ok, it's a more efficient way of burning coal. You're still CO2-emmision positive.
    - ars 11y ago
      > You're still CO2-emmision positive. And so what? I said that, did you not read what I wrote? I'll quote it for you: "this will greatly reduce CO2 emissions, even though it's not completely zero." > more efficient That is way underestimating it, it's a fraction of the CO2 output of any other fuel. By far most of the energy comes from the sun, only a small amount comes from the coal. And it's pollution free since all the heavy metals in coal are captured at the source. It also fits in well with existing technology since there don't exist any other ways of transporting fuel in bulk except hydrocarbons. There simply doesn't exist any other way of doing it. Have you ever heard the saying "The perfect is the enemy of the good?" Trying to be eliminate CO2 entirely is impossible, if you hold out for that you'll do nothing whatsoever.

lvspiff 11y ago

>> "I think the only reason to pursue [solar panels in the Sahara] would be if it were a stopgap measure in which the long-term goal would be to reduce consumption of energy and to change our lifestyles to be more sustainable, so that subsequent generations don't have to deal with as many problems as we're going to leave them." I hear this logic a lot and disagree. Finding more sensible and environmental ways to produce electricity needs to be the goal because we cannot be more sustainable. Mankind thrives on energy. I think the past 263 years (since Franklin's kite experiment) have shown us electricity is a way of progressing. We need power to run things. Where that power comes from is the difficult part. Unless another form of energy is found that can be used to work everyday devices from phones, to computers, to lights, not sure how we get away from electricity and only continuing to increase its consumption. As for paneling the desert - The massive solar arrays in the Mojave desert outside of Vegas show that the sun can be used effectively, but the cost to produce the materials and impact on desert flora/fauna that go into the arrays are just as bad for the environment. The material cost alone in terms of environmental impact make it a laughable endeavor in terms of "environmental" concern.

bendykstra 11y ago
I don't like her analogy in which she compares solar panels to smokestacks. As she points out, smokestacks were not a complete solution to air pollution because they merely moved the problem somewhere else. Solar panels are in no way comparable in that respect. The analogy only works if you consider energy production to be itself a problem.
- acheron 11y ago
  "The analogy only works if you consider energy production to be itself a problem." Welcome to environmentalism.
- Edmond 11y ago
  She could simply be trying to say that nothing is ever free. Conservation of energy dictates you need energy to produce energy, no matter the tricks you use to get energy there is always a cost even if it is not immediately apparent.

anindyabd 11y ago

So the technology is already there, but we can't/won't implement this because of politics? What a shame!

eloff 11y ago
When there's enough money to be made in it, private industry will just make it happen. We're not quite there yet, but it seems likely to happen as prices for solar keep falling. Politics don't have to enter into it, but government involvement has the potential to speed up the process.

stevefeinstein 11y ago

The Media always seem to frame questions like this wrong. The question to ask is, "Why shouldn't we solar panel the Sahara Desert?" And once that question is answered we get started.

iSnow 11y ago
Well, the industry asked the question and then left the DESERTEC consortium.

_ph_ 11y ago

The sahara could be a source of endless solar energy. But for the obvious political and technical considerations Europe probably first should look into installing large solar plants in Spain, Italy and Greece. Not only would it support the economies of those countries, but it would be very easy to connect those solar farms to the European grid. Also it would give a nice daytime distribution of the power as Spain and Greece are at the western and eastern borders of the European Union.

notatoad 11y ago

We should not be covering any wilderness (even a relatively barren wilderness like the Sahara) with solar panels until every inch of roof in the developed world is covered in solar panels. There's a ridiculous amount of flat open surface that is just wasted space right now, and not only is the space going to waste but the energy consumers exist right underneath that wasted roof space.

AC__ 11y ago
While I agree with your sentiment the problem is that solar panels in populated urban areas that are perpetually blanketed by geoengeering spraying practices are not going to be nearly as efficient as ones in dedicated remote areas not being sprayed.
- charlesdenault 11y ago
  Chemtrail citation needed.
  - AC__ 11y ago
    https://www.reddit.com/r/conspiracy/comments/1x6r81/huge_list_of_geoengineering_links_and_evidence/ https://www.reddit.com/r/conspiracy/comments/1x6r81/huge_lis...
    - AC__ 11y ago
      Geoengineering is undeniable don't be ignorant. Either you can't read or you are a shill.
      - AC__ 11y ago
        I forgot to tell you to gfy. I will never capitulate.
      - AC__ 11y ago
        I forgot to tell you to gfy. I will never capitulate.

charlesdenault 11y ago

A distributed system of solar arrays intelligently placed on top of every building in the world, back-feeding into the grid or powering on-site batteries (Tesla Powerwall, etc.). Or massive array in one geographical region susceptible to natural disasters, politics, or terrorism. I'll take the distributed system.

pm90 11y ago
There are benefits to both. You can't use a distributed system for, say, Aluminum smelting, which requires tons of electric power. If the idea suggested in the article is implemented, the Sahara could be turned into a "powerhouse" and an invaluable economic resource to the rest of the world. Integration of this system into the global economy would entail tremendous changes to both the world's interest and understanding of Northern Africa.

abalone 11y ago

What about water usage? At scale, doesn't it take a significant amount of water (for a desert) to clean the dust off the panels?

jws 11y ago
Brushes are fine.

zobzu 11y ago

who's going to dust the sand off the panels, with what energy though?

marshray 11y ago
Sounds like a do-able job for robots, perhaps evolved from windshield wipers.

graycat 11y ago

What to do with the resulting electric energy? (1) Smelt iron or aluminum? (2) Split H2O into O2 and H2 and use the H2 for fuel. (3) Convert water and coal to gasoline. (4) Desalinate and/or purify water and use the water for humans food and drink, bathing, washing, swimming, lawns, greenhouse agriculture, or just to make the desert bloom? (5) Heat salt to store the energy, and then run water through tubes in the hot salt to generate high pressure steam to drive steam turbines and, then, electric generators and, then, transmit the power across the Mediterranean to Europe and sell it? Uses (1)-(4) have the advantages that get just to use the power while the sun is shining and don't have to store the power for nighttime use or transmit the electric power long distances. Would have to transmit the hydrogen or gasoline for those options. In the words of the skeptical mayor's wife in the movie The Music Man, "I'm reticent. Yes, I'm reticent." Why? The idea is not nearly new. So, I do have to suspect that a good engineering-economic analysis would show that we would need progress in: (1) Keeping desert sand off the solar panels. (2) In case want to use the electric energy to make hydrocarbons, a good source of coal near the desert. (3) Energy storage. (4) Superconductivity for the transmission lines across the Mediterranean. Might be able to pay for it if the world can agree on some huge carbon taxes. Nukes might be be cheaper. Might keep in mind that the spot, wholesale cost of electric power in the US has been under $0.01 per KWH and the full cost, say, ballpark $0.06. So, the cost to a consumer of 10, 12, 22 or so cents per KWH is mostly for distribution, not generation. But the panels in the desert handle only the generation part, do nothing for the short distance distribution costs where the consumers are and make the long distance distribution, e.g., across the Mediterranean, more expensive. Also on the money side, might want to keep in mind that the major oil sources in the Mideast pump oil for less than $1 per barrel. That price is tough to compete with. Right, might be shipping the power to France which is doing quite well with nukes. Then once carbon taxes start to take hold, people might watch 'The Great Global Warming Swindle' at https://www.youtube.com/watch?v=52Mx0_8YEtg https://www.youtube.com/watch?v=52Mx0_8YEtg and discover the evidence that CO2, methane, etc. from human activities has nothing at all to do with the climate or temperature of earth and, instead, changes in those two are driven by changes in the activity level of the sun, the sun spots, the solar wind, the blocking of cosmic rays hitting the atmosphere, the rate of formation of water droplets, the rate of H2O cloud formation, and, thus, the cooling effect of clouds. Then people will object to carbon taxes. Net, it appears that while the Watts of solar energy per 1000 square miles of desert are astoundingly high, for what people in the population centers want in electric power, motor fuel, clean water, etc., that desert solar power is just not very valuable.