Gerhard Knies

Gerhard Knies

Chair of the Supervisory Board, Desertec Foundation; Trans-Mediterranean Renewable Energy Cooperation (TREC), Hamburg, Germany

We all know that one of the key challenges of our time is to find new sources of energy – but most of us wouldn’t look for it in the Saharan desert. Why not? More energy falls on the world’s deserts in six hours than the world consumes in a year. The Sahara, the world’s largest desert, is virtually uninhabited. Building solar thermal power plants in this vast space could generate electricity, which would then be transmitted to countries in Europe and Africa through high-voltage direct current transmission. Due to the high solar radiation in the Sahara, such plants could deliver fifteen percent of electricity needs in Europe alone – one sixth of its electricity.  To make this revolutionary idea for carbon-free power generation reality, the physicist Gerhard Knies (1937) initiated the Desertec Industrial Initiative, which aims at finding sustainable power supply for all regions of the world with access to deserts. Desertec is supported by a consortium of companies from various European countries, which strive together to make use of one of the biggest naturalsources of energy: desert sun.

Breaking the Wall of the Fossil Age. How Desertec Can Overcome Energy Resource Limitations and Global Warming.


20 years ago: The way the wall fell was a big surprise to me!

The 9th of November 1989 I spent in Hamburg. I watched the evening news at TV with my wife. We had been following closely the events going on in East Germany, because we had a number of friends there. Then we saw Mr Schabowski and his message. Spontaneously we decided to go to Berlin early the next morning, and when we arrived the roads were flooded with champagne bottles. We decided to see our friends in East Berlin, passed the checkpoint Invalidenstraße and then we celebrated and got drunk. late at night, but before 24-o-clock, we should have gone back. We thought, “Oh no, we are too lazy; now we stay.” This was, of course, in violation of the laws of GDR. Let’s see what happens. Next morning we came to the checkpoint. The officer said, “You have violated here the regulations”. Well, what shall we do? “If you promise that you won’t do it again, I will let you go.” How true he was!

About 60 years ago I received a book with the title: Energy of the Future. It was on nuclear energy and on fusion. I guess that implanted this question into me, and I never got rid of. Then, about eight years ago when I retired, I took that question really serious. Energy of the future? That is why I am here in this terrific line-up of speakers. Thank you, organisers. And I will tell you what I have found out on which walls have to fall for ten billion people to live on the earth, and how DESERTEC can overcome energy resource limitations and global warming.

How can ten billion people live on earth may sound like an academic question, but now it is not so insane to look at it. It was addressed already by the Chancellor this morning that we are approaching that number. It has been found out actually that a meteorite is on collision course with earth. It will hit around 2050. The meteorite are the 10 billion people. They may have similar effects as a meteorite, which would disturb the atmosphere and living conditions tremendously, because this ten billion people will hit an earth with a carrying capacity at that time for about three billion. Now it is just below five billion, and it is being degraded by the use of fossil fuels mainly. The point is, if we get rid of fossil fuels and turn to clean energies, we would not only stop further degradation, we could even upgrade the carrying capacity to about ten billion people.

Clean and secure energy/power is key to upgrading the carrying capacity of planet Earth for a population of 10 bn people. By creating civilization and wealth for everybody population growth can be ended.

Upgrading the carrying capacity is the most urgent task for the global community. This requires some special actions. That is why I think the security paradigm of this century is no longer national security but rather human kind survival: not the defence of national borders but of human living conditions. I will now tell you how I think that we have a chance of coping with energy and climate problems. Many scientists say,  two degree is the most that we can allow as global warming. At each party, G1, G2, G8, G20, G100, whatever Gx you have, the 2° are celebrated. But I don’t think that those people really know what they are promising or aiming at.

It was the Wissenschaftliche Beirat der Bundesregierung für Globale Umweltveränderungen (WBGU), which has put it into a number: How much carbon dioxide can we still put into the atmosphere if we want to keep that limit? Here is the answer: worldwide 750 gigatons. What does this mean in terms of what we are doing now? This means that the world can continue with the present rate of carbon dioxide emissions 25 years, and then this budget is used up. Then the meteorite will come and hit. Industrialized countries have around 10 years left with their budget, later developing more around 60. This means: only by global cooperation we still can achieve climate security.

We need a powerful strategy for global decarbonisation. I want to show you one such strategy. Well, lets talk about DESERTEC for the whole world. DESERTEC means:  deserts and technology for energy, water, and climate security.

The little red square receives from the sun as much energy as the world’s population is using, everyday, every month, year. It covers less than ½ % of global desert space.


Firstly, we see there is enough space in deserts to make this a global solution. Secondly, we see deserts go around the world. These are two important parameters. Now, of course, to bring this energy to people requires something more. First we have to bring it into a form, which can be transported, and that is electricity, for instance. The expected consumption 2050 is 60 PWh/year; Germany has 0.5 PWh/year right now - just to set a reference. If half of world demand in 2050 would be produced by solar collectors, then we would need collectors for 12,000 gigawatt electric. They would occupy one percent of desert areas. So, the resources are there.

Now, this electricity has to be brought to people. This can be done by existing technology, by high-voltage DC transmission power-lines, a super grid. More than 90% of world population can receive clean power from deserts with losses of less than 10 % by power lines of 3000 km length, at most.

And this is the way how solar energy is converted into useful energy: solar radiation is collected and concentrated by parabolic mirrors onto heat absorbers. They will heat up and generate steam. The steam drives a turbine. Hence we have a very conventional steam power plant at the end. There are also some other technologies, like photovoltaics, but the solar-thermal way has intrinsic energy storage capability.

This is a very important feature. Heat from additional collectors is used to heat up during day time molten salt contained in these big cans. From this stored heat you can generate steam and solar power also at night. So, you have solar power available day and night. With this technology, the storage problem is solved.

Such a system, which has a solid and firm capacity for solar power generation, has been studied by the German DLR, just for the EU-MENA region.

Power sources included in the EUMENA scenario studied for DESERTEC: wind, photovoltaic (PV) in the North, and concentrating solar power in South, and biomass, geothermal, and hydro.

This full system of clean power is then introduced step by step over the years until 2050, always suppling the full expected demand and providing secure capacity (for more details see On this map you don’t see any borderlines anymore, so we are thinking of the world without national borders. This is very important.  This is the key to global energy and climate security.

The resulting decarbonisation in 2050 is a reduction by 81%. This is what is needed to be compatible with the climate goal of less than 2° C for global temperature rise. This can be done here, and it can be done all over the world.

Hence, the answer to the question: can the DESERTEC approach protect us? is yes. To say it with Radio Eriwan: in principle yes, because there are still a number of obstacles in the way - some walls, which have to fall.

Walls to fall for ending the fossil age are the following: first the over-emphasized National Sovereignty. Let me just give you a few comments on that. We observe that the nationalisation of global tasks leads to a disaster for a mankind of ten billion people. Proof: look at the 15-year-long history of failures in setting up the desperately needed global climate protection framework at these climate conferences of nation states as negotiators: Prioritizing National Sovereignty prevents us from doing the best at global scale, where we all depend on, and keeps us on the rails towards a global climate disaster. Instead of organizing global transition to better and permanent stability, nations fight to get the biggest chunk of the remaining fossil resources. The continued rivalry among nation states thus becomes war against the generations to come. Over-emphasized National Sovereignty has to fall. Here I agree with the Chancellor and what she said this morning to this point.

Secondly, there is lots of ignorance around. Continuation of fossil age, which means expanding the use of fossil energies for powering our civilisation, is indeed preparing genocide. We know that the world has only something like 25 years left for emissions as now before climate change may get out of control. This says that those walls keeping us on the present path of large-scale destruction of our own living basis, earth, had better been torn down yesterday. Ladies and gentlemen, which ignorance is in the way? Well, some people claim that we don’t have enough alternatives for these fossil fuel supplies. Well, the DESERTEC potential I showed to you demonstrated that this is not correct. Clean power from deserts offer us more than 100 times the capacity for power than needed for global energy demands. Deserts receive in six hours as much energy from sun as mankind is using in one year. The wall of ignorance about over-abundant wealth of resources of renewable energies, notably of solar radiation in deserts, needs to be torn down.

Thirdly, ignorance about technology: some people believe or claim that we don’t have the technologies yet to make deserts to global powerhouses for ten billion people. The DESERTEC concept, for which the technology has been studied carefully, demonstrates that over 90% of the world population can be served with power from deserts: day and night, summer and winter, with existing technology. Any conceivable amount of energy can be generated from desert sun, and can be transmitted over several thousand kilometres. Almost all energy services can be provided by electricity, and thus can be based on clean and inexhaustible power. The wall of ignorance about technologies like concentrating solar thermal power and long-distance transmission has to be torn down.

Another wall: blindness with regard to future in market economy. Some people claim that clean energies are not affordable. Yet, ladies and gentlemen, is the destruction of global living conditions more affordable? Is handing over our children and grand children, and so forth, to a world wrecked by climate change disasters more affordable? Yes, this is what market economy will deliver. And global warming will not only create melting of glaciers. It will cause melting states and melting living conditions. The DESERTEC concept shows that clean power from deserts can be delivered at any desirable amount to anywhere where it is needed. So, while expanding the use of fossil fuels will drive up their costs and accelerate their depletion, the transition to clean power will bring costs down and extent our ability of tapping into the vast renewable energy sources.. It would cost about 20 to 50 billion Euros to introduce this DESERTEC concept as a global solution.

Is that amount an unbearable burden? It is neither unbearable nor is it a burden. More and more people are beginning to recognize that saving the world will not be a burden or a punishment, but will be the investment most appreciated by the following generations, and will become the largest business opportunity for the present ones.

Thank you very much.