Research On Risks In Offshore Wind Power Development

Along with the constraint of remaining land and electricity gridcurtailment of onshore wind farms seriously highlighted, large-scalecommercialization of offshore wind power development will be a newdirection, will increase rapidly in the next five to ten years. In the early stageof offshore wind power project development of China, the research on riskfactors is not comprehensive and deep adequately, the research on some riskfactors is deficiency and insufficient. Combined the actual practice anddeveloping situation of European offshore wind power development, as wellas the actual situation faced by China wind power, from the five aspects, thewind resource assessment, the energy yield, the offshore wind turbines, theconstruction and installation and the maintenance, researched theidentification, analysis (qualitive or quantitive) and control of these riskfactors.Combining the wind resources assessment and energy yield work ofoffshore wind farm A in Euro, analysised the risk degree of the statistic errorand systematic error hidden in the offshore wind assessment, includinginstrumental error, availability, distortion effect, vertical extrapolation,horizontal transformation, duration of the data set and long-term trends, thenthe total influence to the result is5.6%. Subsequently, quantitatively studiedthe impact degree of uncertainty risk (the power curve, wake losses, electricallosses and availability) on the energy generation is9.6%totally (includingrisks hidden in wind resource assessment). Assessed and analysised typhooninfluence on power generation of offshore wind farms in China, in Fujian,Guangdong, Hainan and Taiwan separately reached2.41%,2.48%,6.5%and10.91%.According to the technical characteristic of offshore wind turbine,combined the increasing trend of wind turbine capacity, the unit cost and the technical barrier, quantitively analysised the construction cost risk (10%)caused by the difference of the wind turbine capacity. Combined the failureinvestigation practice of gearbox and direct drive system, qualified the failurerisk separately at2.2%and1.2%. Compared advantages and disadvantages ofthe gearbox-drive and direct-drive, then the direct drive offshore wind turbineis recommended to Chinese wind turbine manufactures for develop.Combing the latest development of European construction technology,proposed that the wind turbine shall be installed entirely onshore. Reachedand found that the capacity of major offshore vessles of China can meet therequirements, also, using two vessles of same model in paralell can improvethe assurance of the construction schedule. In the study on constructionschedule, suggest emphasizing the consideration of the risk of “weatherwindow” and the capacity and availability of vessles.Combining the statistic data of the operating offshore wind farms in Euro,analysised and quantitized the individual maintenance duration (9days), theimpact of individual failure of gearbox on wind farm availability is0.45%andits maintenance cost predicted is9,354,000￥/year.