Sunday, March 28, 2010

Jive Castles In the Air

President Obama promises to save us from carbon climate doom, using the wind. Should you trust this man's promises?
A recent detailed analysis (focusing mainly on Spain) finds that for every job created by state-funded support of renewables, particularly wind energy, 2.2 jobs are lost. Each wind industry job created cost almost $2-million in subsidies. _FP
Of course Mr. Obama may feel that with the aid of the mighty printing press, he can create as much cash for subsidised green jobs as he wishes.

In an earlier Al Fin post, I alluded to the high cost of maintenance for wind turbines. We are not supposed to notice or talk about such things as maintenance -- even though such mundane matters are often the ruin of great and ambitious undertakings. But wind turbines are expensive, precision made machines that are exposed to the elements, and subject to prolonged and violent motion. They break down -- expensively and often.
The wind energy industry has experienced high gearbox failure rates from its inception [1]. Early wind turbine designs were fraught with fundamental gearbox design errors compounded by consistent under-estimation of the operating loads. The industry has learned from these problems over the past two decades with wind turbine manufacturers, gear designers, bearing manufacturers, consultants, and lubrication engineers all working together to improve load prediction, design, fabrication, and operation. This collaboration has resulted in internationally recognized gearbox wind turbine design standards [2]. Despite reasonable adherence to these accepted design practices, wind turbine gearboxes have yet to achieve their design life goals of twenty years, with most systems requiring significant repair or overhaul well before the intended life is reached [3,4,5]. Since gearboxes are one of the most expensive components of the wind turbine system, the higherthan-
expected failure rates are adding to the cost of wind energy. In addition, the future uncertainty of gearbox life expectancy is contributing to wind turbine price escalation. Turbine manufacturers add large contingencies to the sales price to cover the warranty risk due to the possibility of premature gearbox failures. In addition, owners and operators build contingency funds into the project financing and income expectations for problems that may show up after the warranty expires. PDF
Gearboxes for large turbines will cost many millions of dollars to replace. And think of all the downtime for all those turbines sitting out in the weather, waiting to be restored to action.
The multiple wheels and bearings in a wind turbine gearbox suffer tremendous stress because of wind turbulence, and a small defect in any one component can bring the turbine to a halt. This makes the gearbox the most high-maintenance part of a turbine. Gearboxes in offshore turbines, which face higher wind speeds, are even more vulnerable than those in onshore turbines. _TechReview
Part of the problem is the constant need for expensive human labour and upkeep -- an expense which many operators of wind farms are reluctant to undergo.
Many wind farm operations and maintenance teams are so resource constrained that they are barely able to keep up with unscheduled maintenance repairs. Even regularly scheduled preventative maintenance such as gearbox lubrication and oil changes are falling behind. It has also been reported that some wind farm operators do not want third-party companies to do the work for them as they want to keep control of the maintenance.

Gearbox failures account for the largest amount of downtime, maintenance and loss of power production for wind farm operators. Failures can total between 15%-20% of the price of the turbine itself. _GearboxMaintenance
Living anywhere within 5 miles of a wind farm can be an unbearable torture as well as a hazard to life and property when blades break and go flying.

These huge wind turbine behemoths are exquisitely susceptible to metal fatigue and mechanical failure. Placed out in wind, rain, ice, and sun, these expensive space-age materials begin to break down the moment they are put in place.

It is not uncommon to pass by a large wind farm on a windy day and see only a relatively small number of turbines actually driven by the wind. In fact, wind energy has become more symbol than substance. Both Warren Buffet and Boone Pickens understand that the tax breaks and other government incentives alone are enough to justify a quick investment in big wind -- whether or not these giant hunks of steel ever produce meaningful power for electrical customers.

Take several minutes to look over this slideshare presentation on wind energy facts. Then ask yourself whether it is worthwhile to build Obama's jive castles in the air, knowing what you know.

Cross-posted to Al Fin



Blogger Jim said...

nice article on the gearbox issues! I invent new gear alloys to increase durability and potentially reduce manufacturing costs. While initially developed for aerospace and off-road racing applications, we're exploring wind turbines to see if it helps in this industry.

6:28 AM  
Blogger al fin said...

Good luck.
It may be easier to solve the maintenance and replacement issues than to solve the problem of wind fluctuation and intermittency.

It plays hell on the power grid, and all associated equipment.

3:20 PM  

Post a Comment

Subscribe to Post Comments [Atom]

<< Home

Newer Posts Older Posts