![]() Moroccan deserts have the highest insolance in the world. Insolance is the solar index, the rating that indicates the amount of solar radiation that hits the earth. This is not to be confused with my youthful insolence upon which adults frequently commented; after all, wasn’t that why my father called me Sonny? But seriously folks, of all the game-changers this series has discussed, this will be the biggest — powering the world by the deserts of Africa. According to an article in the Guardian 2011, during the summer of 1913, in a field just south of Cairo on the eastern bank of the Nile, an American engineer named Frank Shuman stood before a gathering of Egypt’s colonial elite, including the British consul-general Lord Kitchener, and switched on his new invention. Gallons of water soon spilled from a pump, saturating the soil by his feet. Behind him stood row upon row of curved mirrors held aloft on metal cradles, each directed toward the fierce sun overhead. As the sun’s rays hit the mirrors, they were reflected toward a thin glass pipe containing water. The now super-heated water turned to steam, resulting in enough pressure to drive the pumps used to irrigate the surrounding fields where Egypt’s lucrative cotton crop was grown. It was an invention, claimed Shuman, that could help Egypt become far less reliant on the coal being imported at great expense from Britain’s mines. Shuman went on to write in Scientific American in 1913: “The human race must finally utilize direct sun power or revert to barbarism.” In 1986, German particle physicist Gehrard Knies calculated that the sun radiates more energy onto the world’s deserts in six hours than humans could consume in a year. The enclosed color image from space by the German Aeronautic Center, or DLR, demonstrates proportionally just how little area is needed from a wasteland to provide energy for the whole world. Herr Professor Knies pursued this venture to later form Desertec. Just think of what could have been, and could still be. No hydrofracking. No selling of national parks to mine coal. Just land that few animals, nor any man, could or would ever want to live on, yet used to produce energy. Morocco has some very big ambitions. The biggest is being the energy provider to Europe. Morocco believes that it can provide a substantial export to Europe’s electricity needs by 2050, enough to factor as part of its economy. The average Moroccan solar day is about 10 hours long. Morocco has the best solar areas in the world, even better than parts of Arizona, which has the largest insolance in the USA. Morocco has the right type of sand as well. It is a denser sand that doesn’t blow around as easily as its counterpart in the Sahara. Ergo, it’s more stable to set the reflectors on and keep the dust off. Now, the Moroccan deserts’ once-arid wastelands may be come the world’s most important site to combat global warming. How’s that for irony! This type of solar power is called Concentrated Solar Power, or CSP. Reflectors To reflect or not to reflect … that is the question. Properly maintained CSP plants will retain most of their output essentially forever. On the other hand, photovoltaic cells will lose about 30 percent over their stated lifetime of 25 years. CSP plants use basic materials like steel, glass, and aluminum, while photovoltaic cells require super-pure silicon, and some higher efficiency units use cadmium and germanium. Another advantage a CSP plant of this magnitude has is it can store large volumes of heat that can be used at night. This plant will provide 3-4 hours of off-sun electricity. However, CSP does have limitations. These are its capital costs, its dependence on large tracts of land, and its advantageous ability of latent energy storage maybe replaced by the advent of better battery technology. Photovoltaic can be placed on existing buildings, reducing the size of photovoltaic farms. And, all centrally located solar farms have the issue of power distribution. How can the power get from the deserts of Morocco to the cities of Europe efficiently? The emerging technology for this support is called HVDC, or high voltage direct current. Suffice it to say HVDC will make power transmission as efficient as we know today. Room-temperature super conductors are a long way off, and their materials most likely would not be cost effective. But for solar farms in the desert, where there is almost no permanent life, solar farms make sense. Storage Reflected power is economical and practical in this neck of the desert because of the ability to store latent heat that is used at night. Since Morocco has a lot of sunny days, it works. Most of the Moroccan solar power will generate heat first, then electricity. There is a mix of photovoltaic in their solar farms. Cost But I wonder … since mirrors have been around for centuries, as heat-concentrating effects of using mirrors (uneventfully) by Archimedes and the screw pump by Archimedes, the invention of the steam engine by Alexander Hero 2,000 years ago, why wasn’t this in place then? Did I digress? Back to solar-concentrating power. This Moroccan initiative, the Ouarzazate Solar Power Station Project, will cost $9 billion for 2.1 gigawatts. This is just about the cost of two nuclear plants. It also takes an enormous amount of space. This current plant, also called the Noor (Arabic for light) Power Station, is almost the size of Manhattan. However, we essentially pay for nuclear plants twice, when they’re assembled and again when they need to be disassembled. Plus, the radiated components must be securely stored for 250,000 years, another cost. Mankind as we know it hasn’t even been around that long. Security As for security, I don’t believe terrorists are going to attempt to sabotage a CSP plant, especially one of this size. If they did they would not get far, nor could they do much damage. Any damage would not have lasting consequences. CSP does not have to worry about a cyberattack per se. It does not require round-the-block, 365-days-a-year security. It does not require refueling. It does not require 250,000 years of secure storage of any radioactive waste. Human error, the cause of all three major nuclear accidents, could not, in CSP’s case, cause substantial damage or serious harm to the environment. Even then, the chance for consequential human error is about zero, except for handling the hot stuff, in this case molten salt. Nobody cries over spilled salt! Maintenance For CSP, the maintenance involves maybe a periodic cleaning with a squeegee, but there is the issue of providing a medium to catch the heat and a medium to cool the steam for the turbine. Water for the Noors plant is pumped in from hundreds of miles away. Dry-cooling techniques that cool the steam for reuse are more in effect today. The early CSP units used wet cooling, which actually used more water than coal plants for cooling. The carbon trade-off is off the charts, but please don’t stare into the reflectors, as it might be the last time you see anything. DESERTEC TREC, the Trans-Mediterranean Renewable Energy Cooperation, created DESERTEC in 2003. DESERTEC was a large-scale project supported by a foundation of the same name and the consortium DII (Desertec industrial initiative) that was created in Germany. The project was aimed at creating a global renewable energy plan based on the concept of harnessing sustainable power from sites where renewable sources of energy are more abundant, then transferring it through high-voltage direct current transmission to consumption centers. All kinds of renewable energy sources are envisioned, but the sun-rich deserts of the world play a special role. There are several projects in Morocco. Conclusion This project has far-reaching implications: a positive and significant change for global warming, a model for future power production around the world (don’t forget China has vast tracts of desert land), heat-storage technology that will advance, as well as given advancements in HVDC central power transmission. HVDC is another topic for another day, though. The vastness of this adventure and the prospect of worldwide emulation ensures electricity as the most robust form of energy for humans. Electric cars will be the mainstay, and hydrogen, or another, safer, fuel made from electricity, will supply our aircraft. Not to mention this project uses land that has no use by any other creature except perhaps through song, like Sting’s botanical anomaly but metaphoric “Desert Rose.” On the political side, Russia has been jerking Europe’s chain for decades by withholding natural gas. Maybe Vladdy should think twice about harassing Europe; otherwise, he and his country will be putting its natural gas where the sun don’t shine.
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AuthorJames Bobreski is a process control engineer who has been in the field of electric power production for 43 years. His “Alternate Energy” column runs monthly. Archives
February 2020
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