(CNN) -- Is green energy a realistic aim for the future? CNN spoke to Gerhard Knies, co-founder and coordinator of TREC, about the potential of solar power and a world based on renewable energies.
Gerhard Knies: "Europe, North Africa and the Middle East could cooperate very easily."
CNN: What is TREC?
Gerhard Knies: TREC is the Trans-Mediterranean Renewable Energy Cooperation. It is a network of about 50 scientists, engineers, politicians and business people.
We are trying to put the deserts into service for energy, climate and water security in a joint effort between the sun-belt (North African and Middle Eastern countries) and the technology belt, mainly Europe in this case. They are close together and they could cooperate very easily.
CNN: What is the potential of solar energy?
GK: Solar energy is Earth's largest and the least-tapped resource. In 5.7 hours, Earth's deserts receive as much energy as the whole world uses within one year.
CNN: How does the cost of solar energy compare to the cost of fossil fuels?
GK: Harvesting solar energy from radiation takes more effort than just pumping oil from the ground, so solar energy is slightly more costly. However, right now, the technology is so advanced that the energy contained in one barrel of oil could be gotten from solar power for about 50 dollars.
We know that the world market price of a barrel of oil is already above that, and the cost of oil does not include the follow-up costs of climate change, of pollution and all of these devastating effects, so solar energy is really becoming competitive with fossil fuels.
CNN: To what degree do you think solar energy will have to become important in the future?
GK: Well, the potential of solar energy is several hundred times the amount of energy we will ever need. However, we have other renewable energies available -- wind, hydropower, geothermal, biomass and so on. My guess is that solar energy will be 40 to 70 percent of the total energy consumption, 30 to 60 years from now. It will be combined with other renewable sources in the most economic way. All these technologies will make their contribution. They supplement each other and give us more security in the supply.
Fossil fuels, which make 90 percent or more [of our energy] at present, have to come down to 10 percent or below to be tolerable for the future and compatible with climate security. It would make it easier to have a secure supply system if we could occasionally resort to some fossil fuel reserves in case there is no wind or too long a rainy season in the solar regions.
CNN: As the world becomes more informed about the climate crisis, is it easier to get funding?
GK: The necessity of a changeover from fossil fuels to renewable energies does not come from the limits of the fossil fuels right now. It is becoming urgent because of the climate change that we are inducing. This is nothing business will take care of because business does not care for the future. Business only looks ahead for a day, a week or a quarter of a year.
It is governments' responsibility to take care of the future, so they have to set new targets for the energy system, develop policies and enforce them. They are beginning to do that right now. Once governments set the right framework, business will follow.
CNN: When are we likely to see TREC's plans come to fruition?
GK: You cannot change the global energy system overnight. It will take 30 to 50 years but we have to start now. All the elements -- concentrated solar power plants and big wind farms in the deserts, transmission lines from the desert regions to the populated regions of the world, from sun belts to technology belts -- are ready to go. It could be operational 10 to 15 years from now. Then it will grow and grow and it could be completed in about 50 to 60 years. But I am afraid that it will take a few years longer because there is resistance to these changes.
CNN: How easy will it be to overcome that resistance?
GK: We have to change our political style, then we can resolve all these problems. If the countries from the sun-belt and the countries from the technology belt would see themselves as a community, they could resolve all these problems. Right now, they're fighting each other.
Countries in North Africa could develop a new source of income by selling clean electricity to Europe. For Europe this would be one of the cheapest sources of clean electricity. It's a win-win situation between the two so they should form an alliance to achieve this.
CNN: What impact will this technology have on the world?
GK: Well, when I say to poorer countries, "Why don't you start to develop these technologies?" they say, "We cannot afford it." The industrial countries, which have benefited from the cheap oil and gas from these regions, should give a return by developing or improving these technologies and bring the cost down so that poor countries get energy and water at affordable costs.
CNN: What will happen if we don't adopt renewable energies?
GK: The transition from fossil fuels to renewable energies, and in particular solar energy, is a very important step for the whole of humanity. We are running out of fossil fuels and then our civilization will collapse without energy.
We are also destroying the climate that we live in. The climate is our home on earth and changing the climate will make many people homeless. There will be migration. This is increasingly realized.