Specification of reliability benchmarks for offshore wind farms

Future deployment of offshore wind farms is perceived as a logical step in energy supply diversification by policy makers and large utilities. Capital costs are high and for this reason the investment decisions are focused on initial expenditure rather than operational costs, which are assumed to be small in comparison. Nevertheless, significant operational issues have arisen in existing offshore wind farms, highlighting the need for consideration of issues such as reliability and its impact on investment payback period. Hence, the key aim of the work is to establish a set of reliability thresholds which may provide important signals to prospective investors on how technical issues such as reliability and maintenance practice can impact on long-term investment decisions in offshore wind projects: aspects which have been largely ignored by wind farm investors until recently. The studies compare the effect of these aspects with more established key metrics such as capacity factor. Capacity factor is a key variable in wind farm design and extensive studies are employed to ensure yield at the sites will be high enough to merit investment. We argue that operational aspects are equally important in decision-making.