Energy Maintenance Systems of South Dakota is one of several companies that refurbishes old wind turbines for resale to small-scale energy producers. (Photo: EMS)Wind energy technology has advanced so much in recent decades that a handful of larger, more efficient turbines can now do the same job as hundreds of smaller turbines, allowing utilities to squeeze more electricity out of the same area of land.
That means that many owners of wind farms built during the California wind rush of the 1980s are starting to upgrade their equipment — and in the process, they are expected to send thousands of worn-out, old machines to the scrap heap over the next five to 10 years.
But a growing number of new companies are snapping up the old turbines on the cheap, overhauling the systems and reselling them to farmers or other community wind developers at bargain prices.
Halus Power Systems in Hayward, Calif., Energy Maintenance Service in Howard, S.D., Aeronautica Windpower in Plymouth, Mass. and Nexion DG in Portland, Ore. all offer remanufactured wind turbines salvaged from wind farms in California.
Many small-scale and community wind projects – which typically generate less than a megawatt of electricity and bring independent, renewable power sources to schools, small businesses and rural communities – have been hamstrung in recent years by the prohibitive cost of new equipment and an inability to compete with larger developers for a limited supply of turbines.
“To go out and build a new turbine of the size we’re working with, it would end up costing twice as much,” said Matt Stein, director of operations for Nexion DG. “And anybody building components for new wind turbines is focusing on the 1 megawatt-plus turbines because that’s where the action is.”
A new turbine runs in the range of $1,400 to $1,600 per kilowatt of generating capacity, which translates to at least $1.4 million for a 1 megawatt turbine, said Mr. Stein. Nexion sells remanufactured 25-kilowatt to 500-kilowatt turbines for about $700 to $800 per kilowatt. Their customers also only wait about two months for a rebuilt machine, compared to the year-long — or more — waiting lists for new turbines.
If a turbine is properly rebuilt, every part from the 80- to 100-foot tower to the blades can be restored to last another 20 years, said Mr. Stein. The gear box, a refrigerator-sized tangle of moving steel parts, is “the heart of the turbine” and the most critical piece to rebuild, he said, because of the amount of wear and tear it endures spinning 1,000 revolutions a minute for years on end.
Nexion also replaces the hydraulic control systems with computerized digital controls that can be monitored over the Internet, and rewires the generator along with degreasing the whole machine and adding a fresh coat of paint.
“It’s not rocket science,” said Mr. Stein, “but if you don’t know what you’re doing, you’re going to put something up in the air that will blow itself up.”
Indeed, if the work is shoddy, the results can be disastrous. Improper maintenance or repairs paired with high winds can cause a wind turbine to spin out of control and explode, sometimes sending its blades half a mile away. (Videos of this phenomenon, like the one above, are available on YouTube.)
The difficulty for buyers and regulators alike lies in knowing when the mechanics have done a good job, said Carel DeWinkel, a senior policy analyst with the Oregon Department of Energy, which is reviewing a developer’s proposal to install 12 of Nexion’s refurbished turbines at a site near Baker City in eastern Oregon.
Used turbines also don’t contain the same warranty guarantees as new machines and require more continued maintenance to ensure they’re running efficiently, he said.
The used turbine market is also suffering somewhat under the current economic crisis, which means that more new turbines are available now, but developers are having a hard time finding financing, said Mr. DeWinkel.
The Oregon Department of Energy still anticipates rising demand for used turbines, however, due to the state’s renewable portfolio standard, which calls for 25 percent of its energy to come from renewable resources by 2025, as well as a goal for 8 percent of the total to be drawn from distributed generation like small-scale and community wind.
The American Wind Energy Association also expects to see more community wind project proposals nationwide in 2009, accompanying new federal incentives included in the Emergency Economic Stabilization Act of 2008 (otherwise known as the federal financial bailout package).
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