In order to tackle global warming, many governments are heavily investing in renewable energy. By 2030, Korea has set themselves the target to produce 30% of their electricity from renewable energy sources. Japan and Taiwan follow with 25% and 20%, respectively. One would say that offshore wind farms are one of the obvious options to achieve these targets, as it is a mature technology, extensively used and proofed in Europe. But is this statement true for all regions? Can we apply the same solutions globally?
In Europe, wind turbines have increased in size and performance outputs, but in general their design and shape has remained the same over the years. With peak gust wind around 30m/s to 50m/s, wind turbines used in Europe are Type 1 class, i.e. that they are prepared to stand peak gust wind not greater than 70m/s. In Asia however, there are unique challenges. Two Swiss Re publications on wind risk assessment models, with estimations about the current and future exposure of the global offshore wind farm market - Wind farms: harvesting energy on shaky grounds and in stormy seas and Offshore wind power in stormy seas - can give you an idea of what to expect. In short, winds change in intensity with speeds easily getting up to 70m/s. Lightening is more intense. Typhoons veer route as well as direction and the traditional long turbine blades are exposed to high bending stress. This calls for wind turbines that can adapt and be prepared to adjust to these changes at all times.
I recently attended the Wind Expo and Conference in Japan where I had the chance to see and inform myself about the latest developments. One of the key topics discussed was typhoon type wind turbines that would fit a wind speed of 80m/s. Another hot topic was downwind turbines. The downwind turbines have the rotor placed on the lee side of the tower and are therefore potentially better suited for typhoon areas. Even if the yaw or direction system fails, the rotor has more chances to survive. With the blade behind the tower, there are no concerns about it hitting the tower during high wind speed. Furthermore, materials can be lighter and more flexible. Increasing output is of course paramount and therefore, manufactures of these new technologies are pushed to produce bigger and more efficient turbines, sometimes as fast as every 12 to 18 months.
Although there are many opportunities lying ahead around the construction and operation of offshore wind farms in Asia, there is also a new set of risks and exposures that all stakeholders will need to understand and tackle. This brings along a new set of still unproven technologies that will need to be evaluated and tested. Swiss Re Engineering stays at the frontier of technology to accompany the transition to cleaner and more sustainable future.
Category: Sustainable energy: Wind