Multi rotor wind turbine systems: an exploration of failure rates and failure classification

The Multi-Rotor System (MRS) is a proposed solution to the increasing costs associated with the manufacture and maintenance of large single-rotor wind turbines. The MRS consists of many small rotors that can capture the same amount of energy as a large turbine but with the added benefits of standardization, reduced system loads, and improved reliability due to the redundancy of components and smaller size. However, modelling the operation and maintenance (O&M) of the MRS presents several challenges, including a lack of available failure data. This work aims to determine, what failure rate reduction, can MRS be competitive with equivalent single-rotor wind farms, using existing single-rotor turbine data as a baseline. The key failure components are identified through the use of a cost-based comparison parameter. Statistical and theoretical approaches are then used to analyse the impact of fatigue on failure rates for downscaled turbines, to determine if the required reduction in failure rate is feasible. Using a case study, the sensitivity of availability, operational expenditure, and lost revenue to failure rates is also determined.