The active and never ending dialogue between Denmark's wind turbine owners and turbine manufacturers has its roots in the monthly operating and production reports voluntarily submitted for the majority of the over 5000 wind turbines in Denmark. These statistics are published every four weeks for all to see. Good production and poor production, defects, accidents, repairs and total wipe-outs, there is no relief for an erring wind turbine company. The manufacturers have not always been enthusiastic about this monthly public exposure, but nonetheless it is the industry which has benefited most from the religious zeal shown by the wind turbine owners association in keeping such a phenomenal system of statistics-gathering on the road. As well as providing consumer information, these statistics have been an invaluable tool for the wind industry when it needed to localise and strengthen the weak links in wind turbine manufacture. Over the past six to seven years, the statistics, among other things, have revealed that gear boxes are the second most troublesome component after control systems. But thanks to the special dialogue between manufacturer and consumer, the industry has a deep fund of experience on which to draw, continually updated and available to all. And that's the way it will continue.
It was therefore with surprise and incredulity that 600 wind turbine owners and interested parties, gathered at a wind seminar in Denmark in the spring, were told by NEG Micon's sales and marketing director Klavs Bech, on behalf of his management, that there were no problems at all with the Flender gear boxes used by the company in 600-750 kW turbines since 1996. A large number of listeners knew this to be no more than wishful thinking. Evidence of what appeared to be a series gear failure had even been documented in the December 1998 issue of Windpower Monthly. The situation was not improved when managing director Jens-Erik Kristensen, quoted in the May issue of this magazine, said the problem, at worse, was just water in the gear box oil and an oil change was all that was needed.
Both the marketing and managing directors have since been replaced and the new management has set aside $28 million for a three-year gear box retrofit program (page 16). Without doubt the gear box defects are NEG Micon's biggest problem, even though serious holes in its business administration contributed to the large deficit projected for this year's financial result. Misinformation about the retrofit program has been rife, not helped by NEG Micon's distribution of a fact sheet in English categorically stating that the gear box repairs would cost $28 million per year, when the sum is actually for the entire program. This led to industry speculation that NEG Micon was shouldering by far the major part of the cost of the retrofit, indicating that gear box supplier Flender was almost off the hook. In fact, though blame has not been apportioned by either company, it appears that NEG Micon will deliver all 1250 or so gear boxes in its big turbines to Flender, which will retrofit them at a new factory in Germany and possibly also in America (page 18). The solemn pledge from NEG Micon's new management is that all the defects and problems uncovered when the gear boxes are dismantled will be solved (page 34).
PLAYING jeopardy
Industry experts stress that this is the only effective solution to the technical problems. Upgrading the bearings alone will leave NEG Micon and Flender in the same position as when they started, or that which is worse. For not only is it NEG Micon's future on the gaming table here. The reputation of the whole wind energy business is at risk. Shock waves from the spectacular implosion of Kenetech Windpower, pushed into bankruptcy by technical failures it refused to face up to, are only now dying away, nearly four years after the event. It is in the interests of the entire wind power branch that NEG Micon be kept to its promise-and the company does not put itself at risk again.
There is still a danger that could happen. Nobody knows the full extent of the gear box problems until they have been dismantled and examined by Flender. But if gear boxes on which pitting of the surface of the teeth has started are not adequately repaired, the fact will soon come to light. Nearly all wind turbine owners in Denmark avail themselves of a service offered by their association-a final and thorough examination of their turbines before expiry of the manufacturer's guarantee period. These guarantee inspections of older NEG Micon 600 kW and 750 kW turbines are already underway. Any problems with retrofitted gear boxes will be revealed. If that happens, NEG Micon and Flender will have put their entire credibility at risk-and spent around $50 million for no reason at all.
