Failure Rates of Offshore Wind Transmission Systems

In the offshore wind industry, failures are often costlier than those experienced onshore. Through examination of the literature, it is clear that failures occurring in offshore transmission systems are not well documented. As a result of this, many developers and other parties involved in the planning processes associated with offshore wind farms will defer back to existing reliability metrics in the public domain. This article presents a review of European offshore wind farm transmission failures based on fusing information from multiple public domain sources. The results highlight both the spread of the reliability performance of these assets and the reliability performance over time. The results also reinforce the industry view that installation practices could lead to low reliability in the initial years of operation, resulting in increased repair costs and decreased revenue for wind farm owners and operators. The information collated in the review is also compared to metrics from across the literature to evaluate the difference in forecasted failure rates to those experienced within the industry. In general, it is found that the experienced failure rates are subject to a much higher spread in practice than those published until now.