Figure 74 Technician carrying out turbine maintenance, courtesy of RWE.
Function
Effective turbine maintenance and service ensures the long-term productivity of the turbines.
What it costs*
About £34 million per annum for a 1 GW wind farm.
Who supplies them
The wind turbine supplier, during the defect notification period (DNP) and for the duration of any agreed contract beyond the DNP.
The wind farm owner may seek to bring service capability in-house or to engage an independent service provider (ISP), which involves seeking agreement with the manufacturer for the supply of spares, software systems and specialist expertise.
ISPs include Aquaterra, Boston Energy, Deutsche Windtechnik, EchoBolt, James Fischer Marine Services, JR Dynamics, Pict Offshore, ONYX Insight, Sedwell, Swire Renewable Energy and 3Sun.
Key facts
The initial service agreement typically covers the period of the turbine defect warranty, which is usually five years. During this period, turbine technicians are typically employed by the wind turbine supplier. The service agreement may specify that on expiry technicians’ contracts are transferred to the wind farm owner. This ensures continuity of staffing and removes technicians’ disincentive to relocate to the wind farm site.
Activity is divided into preventive maintenance (scheduled) and corrective service (unscheduled) works. The bulk of preventive works will typically be carried out during periods of low wind speeds to minimise the impact on production, however, in practice, this is not always achievable.
Corrective service is performed in response to unscheduled outages and is often viewed as more critical, due to accruement of downtime until the fault is resolved. The primary skills required are mechanical or electrical engineering, with further turbine-maintenance training often provided by the relevant turbine provider.
Typical maintenance includes inspection, checking of bolted joints, and replacement of worn parts (with design life less than the design life of the project).
Unscheduled interventions are in response to events or failures. These may be proactive, before failure occurs, for example responding to inspections of from condition monitoring or reactive (after failure that affects generation has occurred).
What’s in it
- Electrical transmission system maintenance