Rethinking How Sahara Can Solve All Our Energy Needs
It is probably over 20 years ago since I read a suggestion for how we can build a hydrogen economy by building solar cells in the Sahara dessert to power electrolysis of water to generate hydrogen. Hydrogen would then be shipped by tankers or gas pipes to Europe, where it would be used to fuel up cars, trucks or whatever you may imagine running on hydrogen fuel cells.
Fast-forward to 2019 and the hydrogen economy is just as elusive as back then. It is easy to become disillusioned. As long as I can remember they have said hydrogen fuel cell cars are right around the corner. Now something did in fact happen, since Toyota actually started selling a Hydrogen fuel cell car and there were incidents of hydrogen fueling stations.
So not a complete failure, just mostly a failure. Yet the world has not stood still. Solar cells have actually made it. New solar power from photovoltaic cells deliver electricity at half the price of new coal plants. That is nothing less than a revolution.
So a solar covered Sahara is worth revisiting. Solar is cheaper and more efficient than ever. Surely there must be some big opportunities here. In fact several organizations have been working on this over the last few years.
The Case for Sahara
This writing was sparked by a recent Forbes article, where a nuclear physicist, Mehran Moalem, explain why nuclear energy could never power most of our future energy needs but that solar could.
Moalem says total power generation needed for the whole world is 17.3 Terawatts (2015). You can provide the power by covering 1.2% of the Sahara with solar cells. The cost would be roughly 5 trillion dollars. For comparison that is less than the Obama bailout, 1/4th of US national debt or 10% of world GDP.
Mehran Moalem goes on to explain how providing this power with nuclear power would cost 52 trillion dollars, roughly 10x as much.
Let that sink in. When I talk to people I realize, most people are simply not up to date on how extremely cheap solar power has gotten recently.
So solar power is where it is at, and Sahara represent a huge potential. It has cloudless and sunny skies, with dirt cheap land. The dessert has little value to most people. Building enormous solar facilities there is thus economically possible. It has even been judged that it would be possible for the Saharan environment, as it would lead to more rainfall.
However there are major barriers to getting this project going. It is easy to build big solar farms where power is actually needed. Very few people however live in the Sahara and need that power. The nations which like to utilize this power are quite far away.
One of the proposed projects involved building large solar farms and very long high voltage power cables to transport this power to Europe.
However the problem with such an approach is that it requires a massive one time investment in power cables, given the huge distance. That means it is not worth it unless, very large power generating capacity is built. This means there is no way of scaling down the project, and build it piecewise. This means a very large upfront investment, which makes it riskier and thus less attractive to investors.
The other earlier suggestion of using power to generate hydrogen or other electro fuels is that people are not going to build this hydrogen generation facilities unless there is a market for it. But it is hard to sell people on hydrogen cars when it is known that hydrogen today is primarily made from fossil fuels. Thus we are in a catch-22 situation.
My suggestion to avoid this problem is to build electro-refineries for metals. This is a technology for creating metal from ore without using carbon. Such an approach will reduce carbon emissions. It avoids two problems:
- We don’t need to build up a market for the produced goods. There is already a large market for various metals.
- Investment can be done piecemeal. There is no singular large investment such as a transcontinental cable which needs to be built before the project has any utility.
It allows us to build up large power production capacity in steps, where each step has some economic rational. This is a bit like establishing a beachhead. We can use this as a starting point to begin the introduction of electro-fuels. That is fuels where electricity is providing the energy for their creation, as opposed to say using photosynthesis as with bio-fuels. One example which I’ve talked about earlier is the use of metals as fuel. The benefit of this is that if you already started making metal in Sahara for the world market, it is a small step to start using that metal as fuel elsewhere.
Of course that is not the only choice. Methanol is also a burgeoning electro-fuel. On Iceland electric power is already used to produce methanol. Other possible alternatives are ethanol, methane, electro-diesel, electro-gasoline etc.
The benefit of producing these kinds of fuel locally in Sahara rather than transmitting power through cables, is that we can scale it up more gradually, and we need to be able to store power anyway. If we just transport the power, we still have the challenge of producing power at night when the sun doesn’t shine. electro-fuels can be burned at any point to produce power.
How To Achieve This
Producing metals using electro-refining in Sahara is likely not going to be cost competitive with fossil fuel based approached initially.
Thus we need rich western countries to commit financial resources to make it a viable business. North African countries spread across Sahara will not have the financial muscle to get this industry started.
We need some sort of partnership where western nations can supply the capital, help subsidize the industry initial in exchange for getting a cut of the profits in the future.
One big obstacle to overcome is the propensity for people to favor building plants locally. Each country wants to build solar cells or processing plants in their country. We need to get people to realize that there is greater potential in teaming up with North African countries and building up this kind of industry there.