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of the turbines can be very expensive due to the additional delays that weather windows can create – certainly compared to onshore wind turbines – and the cost in terms of lost revenue and operation and maintenance expense will be that much higher. MM. Offshore turbines have to prove durable, above all. Offshore turbines face corrosion issues and have to withstand greater wind speeds. Therefore, reduced maintenance is a key factor in cost efficiency and not an easy problem to overcome, as we have seen on the back of the experience by more than one manufacturer. Both onshore and offshore face the challenge of reducing component weight and logistical complexity for transport and installation. In addition, the increasing scale of offshore projects will put a great deal of focus on the efficiency of the performance of offshore turbines; when considering multi-gigawatt Round 3 developments, small differences in efficiency will be considerably amplified. How do you see innovative engineering within the context of wind turbine manufacture developing over the next decade? RC. It is a fact that the use of tension control technology can result in wind turbine designs that require up to 50 percent fewer bolts on critical joints for the same service rating. Th is significantly saves money in production build, installation and maintenance – less bolts, less drilling, less tightening, less checking. Th is innovation alone has the potential to significantly impact the future of wind turbine manufacture, as well as maintenance regimes. Reliable, maintenance-free bolted joints will become the ‘norm’ if the science is applied. CK. Technology development in the largest unit sizes of conventional wind turbines has been particularly stimulated by the emerging offshore market, and many of the most innovative wind energy systems proposed in recent years target that market. The wind energy sector is also borrow-
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ing much experience and expertise from the offshore oil and gas sector. Some of these systems may be the way of the future; some will undoubtedly disappear from the scene. At the very least, they illustrate the huge stimulus and demand for creative engineering that has arisen from the establishment of wind energy technology in the power industry. MH. Whilst there appears to be another push being made towards increasing the MW capacity of wind turbines – particularly in the offshore industry – I am not convinced that this is what developers, investors and lenders really want. Instead, they are generally satisfied with the current levels of capacity and would prefer that turbine manufacturers focused on making the turbines more efficient and more reliable. This not only saves them a degree of costs but generates more revenue in terms of return per €/MW of capacity. A key area of engineering which would be a welcome development over the next decade is the potential ability to make gearboxes more reliable. Therefore, having more turbines which can be ‘gearless’ would be a welcome development if this cannot be achieved, or as a wider alternative. Finally, given the greater lengths of turbine blades, will we see a growing use of lighter, stronger blades that are made out of carbon fibre? Currently this is cost-prohibitive, but will this be the case by the end of the decade? MM. The challenge posed by direct drive turbines will move increasingly to the fore in the next decade, both onshore and offshore. Aside from turbine vendors continuing to improve their proven designs, there are also several start-up initiatives out there to increase the efficiency of existing turbine technology, be it laser-monitored blade rotation or gas/wind hybrid technology solutions to reduce intermittency, although the commercial deployment of these solutions is obviously not guaranteed. Beyond concerns of wind turbine efficiency, the issue of wind power availability will be helped considerably by affordable wind energy storage solutions.
Mark Henderson is responsible for Investec’s power and renewable energy sector investments in Europe. He has over 23 years’ banking experience. Before joining Investec in 2004, Henderson was at Société Générale and Dresdner Kleinwort Benson.
Marc Mühlenbach is is an analyst in Emerging Energy Research’s Europe Wind Energy Advisory Group, providing market research and analysis on the European wind energy market environments.
01/09/2010 14:46