A trend line suggests O&M costs actually go up over the time period of consideration, especially when considering new data as a result of this survey. This is also supported from anecdotal data suggesting an increasing trend in wind O&M costs. Scatter is also observed with the Lawrence Berkley National Lab data, confirming that the variability of the new O&M cost data is not new.
Additional survey data contained cost estimates for wind turbine O&M costs per MW installed per year. These values were $40,000 (€28,000) per MW per year, with a standard deviation from the mean of $12,000 (€8,500). Among the anecdotes pulled from interviews was the observation that in the 2002 to 2003 time frame O&M costs had been estimated at $15,000 to $20,000 per 1.5 MW unit, but instead the true cost average is $40,000 to $50,000 per unit per year, after warranty. Another source estimated O&M expenses at $40,000 per 2MW unit, with $1.5 million per unit being the worst-case scenario.
A summary of primary findings on O&M cost trends derived from a series of confidential interviews includes these observations:
• O&M costs for wind power are far higher than originally projected, particularly in the U.S., now the world’s largest wind power market.
• A particular turbine operating reliably in Germany at a less than 20% capacity factor may experience catastrophic failures in the U.S. operating at a 35% capacity factor, due to more rigorous wind resource regimes.
• The U.S. wind resource results in much higher power production at far lower end-use power costs, but at the expense of often unaccounted O&M costs, an issue that has been largely “under the radar” due to warranty coverage.
• Europe’s premium power prices allow for more preventative maintenance and, therefore, overall lower maintenance costs than the U.S. Also in the U.S., annual power production is down 2 to 5% if compared to European turbines when resource factors are accounted for.
• The U.S. has, on average, lower availability than Europe. This fact appears to be a reflection of better O&M service arrangements in Europe, a theme explored further in the next report section.
• Problems with gearboxes and blades throughout the global wind-power industry peaked in 2007 to 2008, though major retrofits will be necessary in the coming years.
• O&M challenges with gearboxes, generators, drive trains and blades have been virtually universal across major brands – though there are a few exceptions with recent upgrades and success stories.
• New direct-drive turbines – the latest design fad – may provide a key O&M solution since they eliminate the gearbox. Hybrid direct-drive/gearbox systems could serve as a bridging technology, much like gas-electric hybrids transformed the auto market.
Component and Sub-Assembly: Data Results and Analysis
An accompanying chart summarizes data for annual failure frequency for various components and sub-assemblies. Annual failure frequency is the inverse of the mean-time between failures for various components and sub-systems.
Data suggests that electrical systems are still the most frequent component or sub-assembly to fail, which was largely confirmed by confidential interviews. These electrical systems consist of myriad components, including breakers, relays, and switching contacts.
Wind Energy Update
Filed Under: News, O&M, Offshore wind