Morocco wants to win more than half of the electricity from renewable sources by 2030. Welthochster Solarturm with 150 megawatts of power is produced between the Atlas Mountains and the Sahara.
Shell construction of the world's largest solar power plant Noor III in Ouarzazate, Morocco. The concrete stump is already nearly 200 meters high, a good 40 meters steel frame follow.
Marrakech (Morocco) - Just before the start of the COP22 climate conference next Monday, the turbulent Marrakech is coming out. "Agir, Actuar, Act" - multi-lingual flags are calling for action on the roads to limit global warming to a maximum of two degrees. The expectations are high after the astonishingly rapid entry into force of the climate protection agreement in Paris. "Now the real work begins. Countries around the world need to devise significantly stronger plans to reduce emissions if they are serious about limiting global warming to significantly less than two degrees Celsius, "says Ottmar Edenhofer of the Potsdam Institute for Climate Impact Research (PIK) shortly before the start of the climate summit.
Host Morocco is also in the middle of a fundamental energy turn, launched with strong international support. Until now largely dependent on imports of fossil fuels, the country wants to gain more than 40 percent of its electricity by 2020 with sun, wind and water. In 2030, the figure will be as high as 52 percent. The dynamic expansion of wind turbines and solar power plants shows that even in less developed countries a comprehensive energy conversion is possible. In the dry and sparsely populated region between the Sahara and Atlas mountains one of the largest solar parks in the world is created. The focus will be on a 242-meter-high solar tower, which is to produce over concentrated sunlight with a capacity of 150 megawatts from 2017 onwards.
"The solar park in Ouarzazate plays an important role in Morocco's energy supply," says Mamoun Bedraoui Drissi, project manager at Masen, the Moroccan renewable energy agency. The first solar power plant in the Ouarzazate complex has already been supplying Wüstenstrom to the Moroccan network for almost a year. The solar-thermal parabolic trough power plant Noor I has a capacity of 160 megawatts. 200 megawatts, the Nachorraftwerk Noor II will also reach with parabolic mirrors from 2017 onwards.
At the same time, the Noor III Solarturmanlage is being built, the almost 200-meter-high base tower of which was recently completed and stands solitary from the dusty construction site. Dozens of workers are currently welding on a steel structure, which is placed on the huge concrete stump and will be more than 40 meters high. With about 242 meters of total height, Noor III will, according to today's standards, be one of the highest solar power plants in the world and be able to carry the title as the tallest building in Africa.
In order to generate electricity from the heat of the solar radiation, a gigantic mirror field is created around the solar tower on a 650-hectare oval-shaped area. The approximately ten meters high concrete pillars for the total 7,400 mirrors are already in the reddish steppes floor. The 180 square meter mirror surfaces of the so-called heliostats are already mounted. In a few months you will focus the sunlight on the top of the tower.
The heliostats can follow the course of the sun in the secondary stroke via a motor control. The bundled sunlight will hit a bundle of hundreds of steel tubes, about 20 meters long, the receiver. These tubes receive a black, heat-resistant paint to absorb as much sunlight as possible. The engineers expect temperatures of about 540 degrees Celsius. This heat is used to heat liquid salts - a mixture of sodium and potassium nitrate - circulating through the steel tubes. The foreseeable quantity of 40,000 tonnes of salt is kept permanently in motion with pumps. They must not cool below 200 degrees during the entire operating period. Then the liquid salts would solidify and clog the pump circuit.
On the ground next to the tower, the liquid hot salt transfers some of the heat in a heat exchanger to water vapor. With this, the turbine of a current generator can finally be driven as in a conventional coal-fired power plant. Since the salts can store the heat well, this process is supposed to continue for up to seven hours even after sunset, and also reliably generate electricity during the dark evening hours. Exactly this storage capability is the central advantage of solar thermal power plants in front of significantly more favorable photovoltaic systems. "In contrast to photovoltaics, solar thermal power plants can produce electricity when it is needed," says Alexander Stryk, a solarthermie expert from the Ingenieurbüro Lahmeyer International in Bad Vilbel. In this way, Morocco was committed to producing renewable electricity during the peak hours during the evening hours.
The solar park in Ouarzazate with three solar thermal power plants and a photovoltaic power plant (70 megawatts) is expected to provide a total of 580 megawatts of power after completion of the construction work in 2018. That is enough for the supply of about 1.3 million people. The costs add up to 2.2 billion euros, of which the Federal Government and the Kreditanstalt für Wiederaufbau (KfW) tax 864 million euros largely as a interest-favored credit. At present there are another four solar parks of similar size in the planning phase in Morocco. The experience from the plant in Ouarzazate will decide which technologies - solar thermal energy with parabolic mirrors or solar tower or even more photovoltaic - will be used in the future for electricity generation in sun-rich regions. "Morocco is in any case a pioneer for the conversion to renewable sources of energy," says Markus Faschina from the KfW office in Rabat. "And this project is clearly beyond the African continent."