Evaluation of Alternative O&M Concepts and Strategies

Matthias Henke
SgurrEnergy Ltd., Hamburg, Germany


To further reduce the levelized cost of energy of offshore wind farms innovative and cost optimized operation and maintenance strategies are required. The industry is moving away from the classic full service long term service and availability agreements offered by the OEM towards in-house maintenance concepts. The expected benefits include reduced costs on one site and increased WTG available on the other. Beside the benefits additional risks need to be addressed to enable bankability.

The different concepts used in the offshore industry have been analysed and compared in detail. The individual risks and possible risk mitigations have been evaluated.

The actual costs of several offshore wind farms in the UK and Germany have been compared and analysed regarding potential benefits of in-house maintenance over OEM provided maintenance.

The presentation summarizes the pros and cons of the different O&M concepts based on the assessment of real data. The risks are further analysed and the results of an operational Quantitative Risk Assessment using Monte Carlo simulation will be shown.

The audience will learn how to mitigate the risks and get an overview of current O&M costs available in the European offshore industry.


An assessment was undertaken on several operating offshore wind farm projects in the UK and Germany taking into account different WTG technologies and size (from 2 MW to 6 MW) as well as the different requirements from the BOP parts (inter array cabling; substation, foundation). The evaluation considered the management of scheduled and unscheduled maintenance as well as the operation, evaluation and management of the available data. Availability and strategies to secure vessels, helicopters, main spare parts and other support equipment has been taken into account as well. An assessment of operational risk using Monte Carlo Simulation techniques was undertaken to quantify potential impacts on the performance of the offshore wind farm.


The assessment showed a significant potential of both cost reduction and improved availability as well when establishing an in-house maintenance concept. Beside the positive effects several new risk items have been identified and discussed. These require additional attention and a clear risk mitigation strategy. The results confirmed the current market trend towards in-house maintenance concepts. However, no concept was identified which fits all projects in general.


The evaluation finally assesses the costs and risks associated with each strategy by benchmarking the different concepts. This includes comments regarding the bankability of the different concepts as project financing becomes more and more important. The key parameter to select the right operation and maintenance strategy for each individual project will be presented. In-house maintenance concepts are considered to have a signification potential to further reduce the LCOE of an offshore wind farm when the set up and management well.


The delegates will received a detailed benchmark of current O&M concepts including cost and availability figures from the current market development in the offshore wind industry in Germany and the UK. The associated risks which new and innovative O&M concepts including appropriate mitigation measures will be presented and support the delegates with their internal decisions regarding set up of new maintenance concepts.