Wind turbine technology has become a fully commercial venture, but the recent rapid growth of the wind industry has strained its supply chain to meet demand in a timely manner. Furthermore, unexpected component failures, especially electronic controls, gearboxes, generators, and rotor blades, have driven up operations and maintenance costs.
During the course of the research for a new report just published by Wind Energy Update, it ultimately became clear that reliable and verifiable data on wind industry operations and maintenance cost trends is quite rare. In fact, there are no current widely available data sets illustrating these wind industry costs.
Proprietary research, reviews of scarce secondary sources and anecdotal evidence obtained through confidential interviews with wind industry owners and operators and component suppliers suggest that operations and maintenance expenses are double or even triple what was originally projected, particularly with the latest class of multi-megawatt machines now permeating the global wind market.
Of course, nearly all machine and electrical components have a certain chance of failure within their design lifetime, and wind turbines are no different. Savvy operators can make problematic turbines look better through innovative in the field operations and maintenance strategies, and vice-versa.
Nonetheless, the wind industry’s promises of delivering cost effective clean renewable energy to combat global climate change is being compromised by higher than expected component failure rates. Gearboxes allegedly designed for a 20-year life are breaking down prematurely across most major manufacturing brands, are failing after only six to eight years of operation.
The key, therefore, to long-term profitability for the wind industry is reducing the risk of operations and maintenance, whether through superior designs, higher quality manufacturing, smarter component transportation techniques, and more strategic installation and field operations (or most likely, all the above).
“Just a one percent improvement in operations and maintenance makes a huge difference on the bottom line,” said one 30-year veteran of the wind industry in the report (which provided confidentiality for those it quoted). “Improved performance is not free, but you’re still not paying for fuel. Operations and maintenance is a much better use of capital.”
This same source made the following startling admission:
Engineers are still scratching their heads when it comes to gearboxes. Even though gearboxes are certified to operate for 20 years, none of them on today’s market last more than 8 years. It turns out that designing wind turbines is tougher than rocket science since the humongous stresses on gearboxes goes all the way down to the microscopic level.
Given the scope of today’s operations and maintenance challenges, owner-operators, component suppliers and manufacturers have no incentive to reveal component failure data because the problems are so widespread. Revealing this data will dampen enthusiasm for wind power, which now has widespread public and policy support.
Why would anyone want to harm their potential bottom lines?
As one large wind turbine fleet manager bluntly stated, “We have the data on O&M costs, but we don’t even share it with the manufacturers. I’ve seen their data, and it is all wrong. The problems are way, way worse than they realize. If you keep a turbine long enough, it will fail.”
The true costs of wind industry operations and maintenance are also clouded by the fact that the majority of current wind capacity is just now coming out of warranty, so most owner-operators do not have access to data about their own wind projects!
On top of that, operations and maintenance costs are affected by specific turbine designs, the nature of site-specific wind resources, siting criteria, terrain and existing support infrastructure.
The majority of those interviewed said larger project operations and maintenance costs range from one to 2.5 cents per kilowatt-hour, compared to an early estimate by the largest U.S. manufacturer of just .5 cents per kilowatt-hour. At 2 cents per kilowatt-hour, operations and maintenance costs are roughly equal to the federal production tax credit offered in the United States as a subsidy to make wind cost-competitive.
A long-term veteran of the wind industry, now stationed in Europe, who was involved with first-generation turbines in California in the early 1980s, made this poignant observation:
[Operations and maintenance] at .5 cents per kilowatt-hour? All of the current figures I’ve seen for operations and maintenance don’t reflect long-term reality. Interestingly enough, even at these high operations and maintenance cost levels, wind projects can still pencil out, especially in Europe.
A warning: generalizations and averages are helpful, but operations and maintenance challenges are often quite site and project specific, with major differences evident between the United States and European markets (as well as Asia and the rest of the world).
A turbine may perform adequately in a typical terrestrial regime with a capacity factor of less than 20 percent in a moderate wind regime in Germany, but exhibit extreme fatigue in a hostile cold marine or scalding hot desert environments and operating at a 35 percent capacity. Terrain and wind regimes play a big role in long-term performance, as do siting protocols, availability of adequately trained labour force, and the quality of component manufacturing.
The current economic recession is a much needed pause, allowing the entire wind industry — including its increasingly large and diverse supply chain — to make a mid-course correction and prepare for the next boom in deployments lying just around the corner.
The industry can no longer afford uneven component quality, long lead times for component replacements, and the high costs attached to catastrophic wind turbine failures.
Now is the time to plan for ways to boost returns on investments by planning ahead and more accurately forecasting operations and maintenance costs — and then respond with corresponding strategies, including a greater reliance upon both condition and performance monitoring systems which can alert operators to potential problems ahead of time.
The key to reducing operations and maintenance liabilities is preventive maintenance substituting for unscheduled maintenance. Here is a list of the primary findings derived from a Wind Energy Update survey conducted for this report:
- The percentage of wind turbines still under warranty during the time of Wind Energy Update survey was 79 percent. Due to this fact, most owner-operators don’t even know what their exact costs of operations and maintenance are. Due to the unexpected high failure rates of major components with the most recent class of multi-megawatt turbines, original equipment manufacturers have no motive to share their failure rate data with owner-operators, let alone researchers trying to publicize these facts.
- Operations and maintenance costs for wind power are far higher than originally projected, particularly in the United States, now the world’s largest wind power market.
- Europe’s emphasis on preventive rather than reactive maintenance results in overall lower operations and maintenance costs than the United States: a 2 to 5 percent advantage if resource factors are accounted for.
- According to this Wind Energy Update survey, the percent change in wind farm return on investment was negative 21 percent with a standard deviation of 13 percent. This underperformance of wind assets is most likely attributed to both differences in power production and operations and maintenance costs over original estimates.
- The same surveys showed that the percentage of total wind initial project costs invested in operations and maintenance was 3 percent with a standard deviation of 3 percent. Many project owner-operators had originally estimated operations and maintenance at one percent of initial project costs.
- Finally, the average values of operations and maintenance costs obtained from surveys were $0.027 per kilowatt-hour. This compares to early estimates by one of the world’s dominant turbine suppliers of $.005 per kilowatt-hour.
Part of the challenge facing the wind industry as it scales up turbines to more efficiently capture the kinetic energy from the wind is pure and simple science. While the weight of larger rotors is designed to capture wind energy increases by the cube, power generation only increases by the square.
In other words, increasing rotor lengths from 40 to 80 metres increases weight (and turbine cost) by a factor of 8, but energy capture only by a factor of 4.
New, more radical designs such as two-bladed rotors, direct drive turbines without gearboxes and even various vertical axis designs are now coming to market as designers seek new innovations to address this fundamental dilemma.
This Wind Energy Update report also chronicles operations and maintenance success stories by General Electric, NextEraEnergy, Suzlon, Clipper Wind, Enercon and Nordic Windpower.
photos: hddod, Clipper Wind