IN Brief:
- Full Circle Wind Services has signed a contract lasting five years to maintain five Nordex N90 turbines at Momerstroff.
- The 12.5MW contract covers condition monitoring, pitch control reliability, converter cooling and protection, and automatic lubrication.
- Full Circle will also manage curtailment and periods of negative electricity prices for owner NTR.
Full Circle Wind Services has secured an operations and maintenance contract lasting five years with renewable energy investor NTR for five Nordex N90 turbines at the Momerstroff wind farm in France. The five turbines have a combined capacity of 12.5MW, and the work includes targeted equipment upgrades alongside routine servicing. The turbines have been operating for around two decades, making reliability and the continued performance of ageing components central to the work.
The contract covers condition monitoring, internal controls associated with blade pitch, selected improvements to converter cooling and protection, and automatic lubrication of important components. Full Circle will also manage curtailment and operation during periods of negative electricity prices. Combining these activities places responsibility for equipment condition and some commercial operating decisions with the same service provider, although the exact retrofit hardware and any guaranteed increase in availability have not been disclosed.
Across the ageing machines, condition monitoring equipment is intended to provide early indications of developing faults so that maintenance crews can investigate before a prolonged outage occurs. Measurements may include vibration and temperature, depending on the monitoring package, with readings interpreted against the turbines’ operating history. The individual sensors and diagnostic thresholds have not been specified for Momerstroff, so the contract establishes a monitoring upgrade without supporting claims about particular detectable defects or prediction accuracy.
Information from monitoring will be considered alongside physical inspections when deciding whether a component needs adjustment, repair, or replacement. Scheduled servicing remains necessary on turbines that have already operated for many years, and not every unusual sensor reading will indicate an imminent failure. Combining the two sources of evidence may help crews distinguish deterioration from changes associated with normal operation, although the results will depend on the installed equipment and maintenance procedures.
As wind conditions change, the turbines’ pitch systems alter blade angle to regulate aerodynamic loading and power capture, while also supporting protective sequences when the machines must reduce output or stop. Internal control faults can therefore affect both availability and the machine’s response to unusual operating conditions. Full Circle plans changes intended to improve pitch reliability, although the extent of any motor, actuator or controller replacement remains unspecified.
Power converters generate heat during operation, and the cooling arrangements must keep components within their permitted temperature limits. As equipment ages, reduced cooling performance can contribute to unwanted trips or component stress; protection functions must also respond when electrical conditions exceed safe operating boundaries. Full Circle will improve converter cooling and protection at Momerstroff, but the contract does not establish a complete converter replacement or any change in their electrical output ratings.
The maintenance programme also includes automatic lubrication for selected moving components, including assemblies where inadequate lubrication increases friction and wear. Automated delivery can keep a supply of lubricant moving according to an established programme, although reservoirs, pipes, and dispensing equipment still require inspection and servicing. Full Circle has not specified the precise components to receive the upgrade or the number of manual maintenance visits it expects to eliminate.
Beyond the physical upgrades, Full Circle is responsible for managing turbine output when network instructions or electricity prices favour reduced generation. Curtailment may be required by network conditions, while negative wholesale prices can provide a separate commercial reason to lower or stop output under the owner’s contracts. Turbine controls must implement these decisions within approved operating limits, and operational records must distinguish deliberate reductions from lost production caused by equipment failure.
When electricity prices turn negative, a generator’s decision to keep producing depends on support arrangements, contractual revenue, and the costs associated with stopping and restarting. Negative prices can arise when supply exceeds demand and some generators are willing to pay to continue exporting, but the correct response for Momerstroff cannot be determined from market price alone. Full Circle will handle curtailment under the contract, with the precise trading thresholds remaining a commercial matter between the parties.
The distinction between intentional curtailment and equipment faults also governs how turbine availability is recorded under a maintenance contract. A deliberately curtailed turbine may still be mechanically and electrically capable of production, while a failed converter or pitch system prevents generation irrespective of market conditions. Accurate records of both states are needed to measure equipment reliability separately from commercial dispatch, although NTR’s detailed performance reporting requirements have not been published.
Full Circle already supports 14 Nordex turbines in the surrounding region, giving it an existing maintenance presence near Momerstroff. Local service capability can help organise inspection and repair work, while Full Circle also provides continuous remote turbine monitoring; its headquarters is in Amersfoort, Netherlands. The five additional turbines are covered by the new agreement, which has been structured around full maintenance responsibilities and the targeted retrofit programme rather than an isolated equipment order.
NTR’s asset operations director Kevin Harrington has connected the investment with the management of wind farms during the middle of their operating lives. The owner must decide which replacements and control improvements can sustain reliable operation over the remaining service period, balanced against their installation and maintenance costs. Neither the value of the retrofit programme nor the timetable for completing each individual upgrade at Momerstroff has been specified.
As Full Circle maintains the five Nordex turbines over the contracted five years, the pitch, converter, lubrication, and condition monitoring upgrades will have to be installed alongside ordinary servicing. Operational records can then distinguish any measured changes in equipment reliability from intentional curtailment during negative pricing or network restrictions. The agreement covers those responsibilities, but it does not specify a guaranteed improvement in output or availability.
