We know solar roofs, they have been popular for quite some time. But now it’s time to think bigger. Trygve Kristiansen is professor of marine engineering at NTNU. He is researching floating solar power, that is, solar cells located on water, or floating solar islands. The professor believes this is a measure that could potentially contribute significantly to the green shift. – By covering between 5 and 10 percent of the world’s hydropower reservoirs with floating solar cells, as much electrical power can be produced as all hydropower does today. It will also have certain other advantages. At any given time, the sun radiates 10,000 times more energy towards the earth than we are able to use. Photo: NASA Can take care of a scarce resource In several parts of the world, water is a scarce resource. And recent research shows that our fresh water is evaporating at a greater rate than first thought. Floating sun can contribute well in this context by reducing evaporation, says Kristiansen. He goes on to say that these floating solar islands are now seen as a great opportunity to provide clean electric power to major cities, especially in Asia. – Many of the largest cities are located by the sea, and floating sun islands will be able to produce large amounts of water. In addition to large surfaces, the sea offers an important cooling effect. But you don’t have to stop there, the researcher believes. There are considerations to be made Floating solar islands can be used to a far greater extent than on only water reservoirs: – If you look at the world’s overall energy needs in 2050 – then we could be even more ambitious. We have calculated that if you put solar islands on 0.17 per cent of the world’s oceans, it will cover the entire world’s need for power, says the NTNU professor. This area roughly corresponds to Norway’s land area twice. One possibility is to use floating solar islands to produce power for floating factories for the production of carbon or hydrogen-based fuel. – All this sounds well and good, but are there challenges? – Yes, there are several aspects that must be taken into account. This will cover large areas of water. And you can then end up in conflict with other interests such as boat traffic, fishing and outdoor life. In addition, it will potentially affect biology with reduced solar radiation, says the researcher to news. Kristiansen says they are working to test the concept in Norway, both on hydropower reservoirs and in the fjords. Ice, snow and changes in the water level pose challenges for floating sun on our reservoirs. Trygve Kristiansen is professor of marine engineering at NTNU. He is researching liquid solar power. Photo: Thor Nielsen – Possible to realize There will be several prototypes of these solar islands around the world. It is still uncertain how big waves the technology can withstand. – They must withstand both storms and exhaustion over time. This is precisely what we are researching. But the solar islands are so different from traditional marine constructions such as ships and oil and gas platforms that there is a lot of unplowed land, says Kristiansen. He adds that it should be possible to realize floating solar islands on a large scale. Solar islands and potential Many companies are now working with this technology around the world. By covering between 5 and 10 percent of the world’s hydropower reservoirs with floating solar cells, as much electricity can be produced as all hydropower does in 2022. It is an advantage to place floating solar cells where there is the least possible weather, wind and waves. In the Pacific belt, for example, there is little wind, and the sun is directly down, so these are places where floating solar cells are well suited. In Norway, varied water levels, ice and snow can create challenges for hydropower reservoirs. If you cover one square kilometer with solar cells in southern Spain, where the annual average solar radiation is 200 watts per square meter, you will be able to produce approximately 44 megawatts. Today’s wind turbines will on average produce about 6 megawatts on the same area.
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Scientists believe that floating solar islands can meet the world’s energy needs in the future – news Trøndelag
