A main complaint was about the difficulty in accessing and analysing the vast streams of data produced by supervisory control and data acquisition (Scada) systems installed by manufacturers in turbines to track and control operation. Suppliers use data to improve turbine performance but are often reluctant to divulge it out of concern that defects will be exposed or commercial advantages revealed.
This prevents operators from collating data needed to maintain machines, said visitors at the November conference. "Suppliers of wind turbines have their data. Mechanics have data, as do technicians in the field," said a delegate from a Dutch wind developer. He added: "I don't understand why it is impossible to work together with manufacturers and technicians to get the data together and send out a report with ten points suggesting where to look (for problems)." Even when data is available, it can be so complex that computers cannot spot problems - human expertise is required.
Inge Aasheim, who co-ordinates wind operation and maintenance (O&M) sales at Swedish manufacturing and technology firm SKF, said the kind of co-ordination demanded by the developer exists in other sectors but has yet to come to wind. When his company installs condition monitoring systems (CMS) - a range of technologies that flag damage to turbine components and enable early maintenance - for clients and seeks data held by suppliers, it is often denied access, he said. Others privately echoed that view, saying turbine manufacturers and plant operators frequently demand that Scada data be destroyed.
The remedy, agreed several panelists, is to demand data from suppliers before contracts are signed. "I think you have to make sure you've got the access from the beginning," said Gordon Smith, a principal engineer of wind turbine monitoring systems at consultancy Garrad Hassan (GH). "Certainly, in other bits of GH where we're reviewing contracts and making recommendations on purchases, we strongly recommend people put in a requirement in the contract to have access to real-time information and historical statistics."
Yet as operation of wind farms shifts to big companies, particularly utilities with long experience in conventional power generation, this promises to open doors, said panelists. One such firm is EDP Renovaveis (EDPR), the renewables arm of Portuguese utility EDP. "We have thousands of wind turbines," said Eduardo Garcia, a technology coordinator at the company. Some turbines have passed their warranty periods, during which Garcia said EDPR lost much access to operational data. "We want to change the position now," he said. "We want to have the data and analysis to put the decisions in our own hands."
Some say Scada data should be better integrated with CMS to reduce costs from breakdowns (Windpower Monthly, May 2008). Signs of wear and tear include vibration patterns and metal residue in lubrication oil.
There is growing interest in CMS. In an electronic poll of wind companies attending the conference, more than half of delegates said they installed CMS in fewer than 25% of their turbines. About 20% had installed CMS in 50-75% of their machines. But more than 80% deemed CMS "very useful" or "absolutely critical". The conference was hosted by Windpower Monthly and was sponsored by LM Glasfiber, Areva, Moog, SKF and Kluber Lubrication.
Toby King, managing director of Moog, a precision instrument manufacturer supplying pitch control systems, explained that wind plant operators pay about EUR0.01 in O&M costs for every kilowatt-hour of power produced. That cost can be reduced by about 10% "just by being more switched on to what's happening to the turbine and why it is down when it is", said King.
The standard cost of installing CMS for 1.5 MW to 2 MW turbines is about EUR10,000 a unit, according to Aasheim. But finding the right system is difficult. Aasheim said whereas only a handful of CMS providers existed a few years ago, today some 40 companies have emerged, making it difficult to choose. Other hurdles include getting the right mix of computer technology able to handle data flow - especially when a fleet of turbines includes several models, Aasheim added.