RUN25+: Reduction of uncertainties for the lifetime extension of offshore wind turbines

At a glance

• A lack of supply chains means that the EU’s and Germany’s expansion goals for offshore wind energy will not be achieved with new wind farms alone. Consequently, it will prove necessary to operate existing farms for longer than the intended 25 years.
• The construction of new wind farms and the associated wake effects influence the reliability and yield predictions of the existing farms and thus reduce their validity.
• This is where the RUN25+ research project comes in. The aim is to improve and link yield and reliability predictions for offshore wind turbines in the operating phase by integrating actual site conditions in order to create a sound decision-making basis for efficient continued operation.

The challenge

Expansion of the offshore wind energy sector is a key component of the energy transition. Germany and the EU are pursuing ambitious expansion goals of 70 GW by 2045 and 340 GW by 2050. However, setting up the supply chains required for this total capacity will take time. Consequently, it will prove necessary to operate already existing wind farms for longer than the intended 25 years.

Furthermore, from a macroeconomic and microeconomic perspective, it is not so much the total installed capacity which is key, but rather the quantity of electricity actually produced: the dense development of the designated offshore areas results in wake effects, which trigger a considerable decrease in the number of full load hours from over 3,500 at present to potentially fewer than 3,000 and reduce electricity production. In order to ensure the cost-effective operation of a wind farm fleet containing older and new wind farms, particular attention must therefore be paid to the reliability and yield forecasts in the operating phase, which take the real site conditions into consideration.

The solution

This is where the RUN25+ research project comes in. The aim is to create an improved decision-making basis for the continued operation of wind farms beyond 25 years in order to contribute to the fastest, most cost-effective, but also most environmentally friendly and resource-conserving implementation of the energy transition. In order to achieve this, the scientists will combine topics in a novel manner that have previously been considered and researched separately in research and technology.

For example, the scientists are developing time-dependent wind turbine reliability models taking operating and environmental conditions into consideration. Methods for assessing site quality in the operating phase are also being improved with a focus on offshore wind energy. Furthermore, models for assessing site quality and site-specific turbine reliability are being linked to produce a time-series-based total cost model for estimating the future yield potential of wind farms.

Fraunhofer IWES is responsible for coordinating all the work packages. The coordination of the project and the work on reliability, maintenance, and cost modeling as well as the linking to a total cost model are the responsibility of the Technical Reliability group, and the Numerical Yield and Site Assessment group is responsible for modeling the site quality in its current and future state as well as for incorporating climate information.

The added value

RUN25+ will provide decision support for lifetime extension of offshore wind farms with significantly reduced and quantified uncertainties in the assessment of yield, taking into account scenarios of future electricity price development. As such, the project will provide an important basis for achieving the expansion goals with the corresponding quantities of offshore electricity. At the same time, the research results will enable the efficient operation of existing wind farms, which results in a reduction in CO₂ emissions per megawatt hour and lower levelized costs of electricity (LCOE).