Reliable maintenance and operation of wind farms

From all our experience as wind farm operators with a total installed capacity of 328 MW from new renewable energies, we know that unscheduled maintenance and troubleshooting are at least as important as regular inspections and scheduled maintenance. In 2017, we began to make our know-how available to customers. Before we launched our services on the market, we extensively tested them in the technical operation of our own wind farm Vetrocom. The result: the availability of the wind farm was over 98% on a monthly and annual basis.

We would like to share this success with our customers and ensure higher productivity of wind turbines. For this purpose, we keep turbine downtimes as short as possible and bring the rotor blades to maximum performance. Our wide range of services for wind farm operators includes 24/7 monitoring, including remote reset and restart, daily reporting and analysis, scheduled turbine and substation maintenance, troubleshooting and repair, and annual inspections.

The biggest challenge is to perform the maintenance and service work on time. This can only be achieved with optimal planning, skilled technicians and good teamwork. The long-term and short-term (daily) planning are very important for effective and on-time use of service staff for scheduled activities. And, of course, at the same time the on-site operational management team must consider possible unscheduled services and if the weather conditions allow work in the wind farm, which makes the organisation of Operation and Maintenance (O&M) activities quite challenging.

Any wind turbine involves different branches of technology – mechanical, hydraulic, aerodynamic, electrical engineering and electronic. And every part requires specific know-how.

Based on our experience, I would say that the most specific know-how is concentrated in wind turbine operation and control systems and in rotor blades.

The blades in particular are the driving force behind a wind turbine and should be permanently in top condition. Due to the fact that they are produced by non-metallic materials and are permanently exposed to severe weather conditions, they need increased maintenance – annual inspections and repairs.

The drivetrain (main bearing, gearbox and couplings) also requires good maintenance with the main goals being the achievement of the highest possible availability and fewer production losses.

The first thing which should be mentioned here is that there are different formulas for availability calculation in use. The formula used by Alpiq is energetic based and considers all possible downtimes which could be influenced by the O&M provider.

In general, the availability of wind turbines is a very important KPI which shows how the unit is maintained. Lower availability means greater production losses and less income. The 98 % availability achieved by Alpiq Wind Services is really high when you consider the special location of the Alpiq wind farm Vetrocom in Bulgaria – at around 1,500 m above the sea level. Usually the wind turbine manufacturer and O&M provider guarantee an availability of 96% - 97%. In some cases, they even have trouble reaching that.

The biggest findings are that we have to deal every day with new situations and to react to them. The daily planning is a very dynamic process, and our local operational management team must always have plans A, B and C prepared so that the staff activity can be adapted to the ever-changing conditions in the wind farm.

Alpiq Wind Services benefits from an owner’s perspective in applying the optimal solutions to maximise production.

Also, the wind turbine manufacturers specialise in their own turbine types. We can offer maintenance services for different turbine types and our target is to expand our portfolio.

Alpiq EcoPower and particularly Alpiq Wind Services have a well-developed and implemented HSE policy. The safety measures during the maintenance work are an integral part of this policy. Every working day starts with HSE instructions on the specific work scheduled for the day. In general, the whole AWS conducts different practical and theoretical training courses on a regular basis – for working at altitude, working with electrical machines and equipment, first aid training and special rescue and emergency training. And for most of these training courses, our technicians receive certificates which are compulsory in order to carry out service or maintenance work in a wind turbine.

It was during my first winter in O&M business by Alpiq. As I already mentioned, the Alpiq wind farm in Bulgaria is located on a mountain (called Stara Planina) located at an altitude of around 1,500 m above sea level and in the winter, the weather conditions are very severe. We needed to provide access through the snow to some wind turbines using a snowplough, but the snow drifts were higher than the snowplough. We had to use heavy machinery – a bulldozer – to reach the turbines and this took many hours.

And in the evening, it started to snow again and the next day the exercise had to be repeated. It was a very tense and difficult experience, not only strange.