Flexible service

Wed, 05/04/2017 - 11:46

Approx. 180 service teams are in international deployment for Deutsche Windtechnik.

As the new support mechanism of tendering begins for the wind power industry, the service and maintenance providers are also adjusting to changes, as our market overview of service and maintenance for this year shows.

Since the start of the year the level of EEG support is being determined by market tendering. Whoever bids the lowest amount for the economic operation of an EEG turbine gets the support bonus. This increases the cost pressures on the turbine operators and also has an effect on the service and maintenance providers. The full-maintenance contracts offered by the turbine manufacturers are less in demand also for new turbines. Instead, more maintenance packages by independent providers are being purchased.

Kai Eckert

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“We are feeling a considerable price pressure,” reports Susann Lemke, head of P&S Service GmbH from Leipzig. She says customers are going more for cheaper package prices, which in turn is putting optimisation pressures on the service providers. “We are now noticing more and more that competitors are partly trying to balance out the price pressures by reducing quality and safety,” says Lemke. This observation is also shared by Oliver Wilhelm, head of Ambau Windservice GmbH from Ritterhude in Lower Saxony: “The price pressures on the service providers are increasing, while at the same time the requirements in the fields of work and health protection, as well as in environment and quality management, are growing.”

A poor understanding of work safety on the part of the customers and in the pricing of service offers is indeed increasingly a problem when dealing with turbine operators, as various providers have confirmed in the market survey. Although a lot has been done towards work safety in the last few years and the number of accidents at work is decreasing, the sector clearly still needs to be made more aware of the subject.

Wind turbines are subjected to very many different and changing stresses when in operation. A regular service and maintenance ensures a reliable operation of the turbines and keeps them in good condition. Many service providers see wear on moving parts, such as gearbox bearings or cog teeth, as a common wear and tear problem for turbines. Flaking and pitting (see box) are named as typical types of damage. They can affect the operation behaviour of bearings and in the worst case cause gearbox damage. Erosion of the rotor blades and corrosion on the tower are also named as typical signs of wear. The rotors additionally face surface or aerodynamic deficits as a result of poorly carried out past repairs or a poor maintenance regime. During tower and foundation renovation the service providers primarily see a building of cracks in the concrete, spalling and corrosion as the main symptoms of wear and tear.

Using a retrofit for digitalisation

Not everyday business: corrosion protection for a WT. (Photo: Ambau)

Condition Monitoring has established itself as the most important tool for monitoring the condition of a wind turbine in the field of technical operation. The systems used for this monitoring can recognise irregularities and anomalies of individual turbine components during operation and automatically sound the alarm. For this purpose sensors are installed at all critical points on the turbine. These are particularly the operational areas which are exposed to especially high loads, such as the gearbox, main bearings and the generator. Apart from on mechanical parts, a CMS can also be used in the rotor blades, however. Here, vibration sensors provide signs of possible changes in frequencies, which can point to the existence of damage. Together with further sensoring and analysis processes a CMS can maximise the availability of a wind turbine and provide a complete overview of the condition of the turbine.

If such a fault monitoring wasn’t installed by the turbine manufacturer right from the start, it can also be retrofitted by independent service and maintenance companies. Six service providers in our market overview provide appropriate solutions for this. Leading the field here is Bachmann Monitoring GmbH from Rudolstadt in Thuringia, which according its own figures has fitted a CMS to turbines with a total capacity of approx. 12,000 MW, and which monitors approx. 10,000 MW of this from its own fault-control centre.

The trend towards digitalisation thus continues to advance also in the wind power sector. The head of Bachmann, Holger Fritsch, expects the subject of safety to continue to grow in importance over the coming years. He has seen a trend towards further professionalisation in the sector, during which additional products to gather and analyse data have been developed. Because of this he expects his service employees to also be especially competent in IT matters, as the communication links at wind farms can have varying degrees of complexity.

The jobs motor is running

Safety training on the climbing tower at the Deutsche Windtechnik Training Centre. (Photo: Deutsche Windtechnik)

Generally speaking the sector still needs personnel. Compared to the responses from the previous year, many companies have increased the size of their service teams. Electrical engineers, electricians and mechatronics engineers are especially in demand. The biggest need for personnel is at Deutsche Windtechnik AG (DWT), by far the biggest independent service provider in the region, which is currently looking for approx. 50 additional service technicians across Europe after its recent expansion into Sweden. At the start of the year the company took on the maintenance of the 6 Senvion M5 turbines at the Alpha Ventus offshore wind farm with its total of 12 wind turbines. According to its own statements the company is to take on the planned maintenance and all repairs for the 6 turbines for the next 5 years in addition to the remote data monitoring and will keep spare parts in stock for this. The wind farm operators are able to lower their operating costs thanks to such standard maintenance contracts. At the same time, especially the big operators can reduce the number of service partners they have and strengthen their partnerships with just a few service partners instead.

At Alpha Ventus, a company involved in the consortium, EWE Erneuerbare Energien GmbH, had already signed a contract with DWT for an identical wind turbine at Neuenwalde near Cuxhaven. This onshore project ultimately served as the foundation for the offshore contract. “The model proved itself, although a certain operator portfolio size was a prerequisite. Cost reduction potentials can be made use of as long as the turbine does not incur any major faults,” says Severin Mielimonka from DWT, explaining the advantages of this type of contract.

Cost optimisation as a driver

“Cost optimisation is a strong driver for us,” confirms Irina Lucke, head of EWE Offshore Service & Solutions GmbH. (Photo: EWE)

With the introduction of the tendering model, large operation companies and investors must look for new and customised maintenance concepts. This is confirmed by Irina Lucke: “Cost optimisation is a strong driver for us.” She currently expects operation costs of 3 to 4.5 cents per kilowatt hour for offshore wind farms. “In the medium term we must get to 2.5 cents per kilowatt hour,” says the head of EWE Offshore Service & Solutions GmbH.

According to her statements, 35 to 40 % of the operation costs go towards maintenance and service. In the coming two years she expects to see stronger cluster building and more partnerships. “Such cooperation is no panacea for farms which are close together, however,” say Lucke, pointing to the tendering model that is generating new competition between the wind farms.

Customised and flexible solutions are in demand

Both onshore and offshore, customised solutions will be in demand as a result of the new orientation. The trend is thus moving away from full-maintenance contracts. Intelligent maintenance concepts and cooperation will provide the necessary flexibility in the future. DWT was already part of the bidding consortium for the tendering of the Alpha Ventus offshore contract. “As a group with various disciplines we bring in a suitable combination of technical competence for the turbines and experience in the planning, coordination and running of offshore projects,” says Mielimonka.

Turbine manufacturers also need to respond to this trend. At the last WindEnergy in Hamburg, PSM Nature Power Service & Management GmbH presented a new maintenance concept together with the turbine manufacturer GE Renewable Energy. In the newly tied-together package, customers can freely select from the complementary services on offer by the two contract partners. They thus benefit from quick response times, favourable prices and the biggest possible flexibility.