STILL conneXXt Nr. 02 English

10 THERE IS NO ALTERNATIVE TO THE ENERGY TRANSITION There is no doubt that the energy of the future (and preferably also the energy of today) must be independent of fossil fuels. In the first case it is blatantly obvious that it is wrong to put all of one’s cards on a finite energy source which will become more and more expensive over the medium and long term. Secondly, using fossil fuels always creates dependency on those countries who are “sitting on” the reserves. And third, even if today’s oil reserves may appear limited, as has previously been the case, there is absolutely no doubt about the limited capacity of the atmosphere to absorb greenhouse gases. DECARBONISED PROCESSES If we want to conserve our environment, we have no choice but to generate our energy in the most CO2 -neutral way possible. In scientif- ic terms the process replacing those processes which release carbon dioxide (CO2 ) with processes which do not, is referred as decarboni- sation. And this is exactly what we need now: in order to achieve the internationally agreed goal of preventing the earth’s warming from exceeding two degrees Celsius, many experts estimate that between 80 and 98 per cent of the world’s present known reserves of fossil fuels need to stay in the ground. And even if this might seem a little utopian, it clearly underlines that our future is absolutely linked with renewable energies. ENERGY HARVESTING The upshot of the above is that the future is electric – because most renewable energy sources deliver electrical energy and not chemical compounds. In so doing they exploit the principle known as energy harvesting: energy is “harvested” and converted into electrical energy where it involves the least effort. This means that wind turbines extract power from the wind, solar plants exploit the sun’s radiation to generate electricity. So far, so good. But there are a many other promising approaches. INNOVATIVE ENERGY GENERATION An example demonstrated in London involved an underground station where piezo-electric tiles were installed: the special panels on the floor converted the energy of walking feet into electrical power. The power generated was sufficient for all of the station’s lighting needs. Although it might be the case in many energy har­ vesting projects that only small amounts of energy are generated, because electronic devices are becoming more and more efficient and require less energy to operate, there are many sensible applica- tions in the pipeline. For instance, in 2013 students at the University of Southampton developed a sleeping bag and a pair of trousers which convert body heat into electricity: enough to charge a mobile phone. They made use of the thermo-electric Seebeck effect, exploiting TITLE STORY a potential difference between the ambient temperature and body temperature. A SEA OF POSSIBILITIES The source of renewable energy with by far the largest power generating potential is the sea: waves, actually. Experts are convinced that theo­ - re­ tically the power of waves could cover no less than one fifth of the global energy demand. Wave-driven power plants are, however, still in the pilot stage. Although having said that, a Swedish company recently announced a breakthrough in the form of a buoy for which they claim five times the efficiency of previously tested systems. According to the company, one single buoy is enough to supply 200 average households with electrical power. The biggest advantage of these buoys is their scalability. In response to demand the number of these floating wave power plants can be increased very flexibly. To date these buoys have, however, only been tested as a prototype in the lab. Many previous designs for wave power ultimately failed because they could not with- stand the overwhelming forces contained in the ocean’s moving waters. A practical test will soon show whether the buoy is all it claims to be and really is a new ground-breaking technology. The use of the ocean’s waves to generate power has one crucial advantage: unlike the wind and the sun, the swell of the sea is comparatively constant and predictable. FLUCTUATING ENERGY YIELD And this describes the central challenge which renewable energy sources face in reality: their energy output is subject to extreme fluctuation. Wind turbines only generate power when there is wind; solar systems only generate power when the sun is shining. And so what the world needs are new energy storage concepts. The demand is for high performance storages which can flexibly adjust to power demand. Ultimately, a society’s demand for energy is not present only when the wind blows. The most promising and currently almost the only technology available is that of the pumped storage power plant. Robust and efficient – one single buoy is claimed to be sufficient to supply up to 200 households with power. Picture: CorPower Ocean AB Lithium is a light metal discovered 1817 by Swedish chemist Johan August Arfwedson. It is used only in battery technology. Lithium is a trace element, the salts of which are frequently present in mineral water. Lithium is also used in medicine. Some lithium salts are used in lithium therapy to treat bipolar disorders, mania and/or depressions. LITHIUM SYMBOL: Li MELTING POINT:180.5 °C ELECTRONS PER SHELL: 2,1 ATOMIC NUMBER: 3

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