NEW ENERGY PAYS FOR PEOPLE & INNOVATION INSTEAD OF FOSSILS

Wind Energy’s New Role in Supplying the World’s Energy: What Role will Structural Health Monitoring Play?
S. Butterfield, S. Sheng, and F. Oyague, December 2009 (National Renewable Energy Laboratory)

SUMMARY
New Energy consistently beats Old Energy at job creation in study after study.

Wind Energy’s New Role in Supplying the World’s Energy: What Role will Structural Health Monitoring Play?, a new study from researchers at the Department of Energy’s National Renewable Energy Laboratory about the technical aspects of making wind projects work better, is a concrete demonstration of how New Energy gets its jobs advantage.

What it comes down to is this: The fossil fuel industries have to get the fossils they burn from the earth. They have automated the dirty and expensive processes so as to eliminate as much of the costly human components as possible.

As demonstrated in studies like Many Shades of Green, Creating Opportunity… and, most significantly, Greenpeace’s working for the climate, the New Energies use the richness of human resources to draw on the gifts of the natural environment. In doing so, they put people to work and nurture the innovation needed to better receive the gift of earth's powers.

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In their paper, the NREL researchers explain how the wind industry has in recent years matured and become able to provide a growing proportion of the human community's electricity demand. While wind is still only about 2% of the U.S. power mix, it has been a third or more of all NEW power built in the U.S. for the last 3 years and the second biggest source of new U.S. electricity generation for the last 5 years. The U.S. Department of Energy (DOE) concluded in 2008 that wind could readily supply 20% of the nation’s power and a recent study of the transmission system for the Eastern half of the country suggested wind could provide even more.

In Denmark, wind is already supplying a quarter of the electricity and it is 8% of the total power mix in Spain and Germany. At several times during recent months, wind was producing more than HALF of Spain’s daily electricity.

The ability of wind projects’ to do their yeomanly work rests on what wind engineers call the “structural health” of the turbines. The building, monitoring and maintaining of structural health is done by human beings. As wind producers’ capacity grows, the need for human beings to build, watch and keep the hardware running effectively and efficiently grows, putting more and more people into quality blue collar maintenance technician and support jobs.

2 important unanswered questions could significantly increase project efficiency:
(1) Can condition monitoring systems analyze the raw turbine data and correlate it with wind conditions to anticipate premature damage?
(2) Can the systems adapt the turbine to the destructive conditions and extend the life of vulnerable turbine components?

A final question the NREL paper only hints at is this: Are high-quality manufacturing and skilled and sensitively performed maintenance, done by highly competent, well-compensated blue collar workers, as much the key to turbine performance as innovative information technology monitoring systems?

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COMMENTARY
A quarter century ago, relatively small turbines with rudimentary controls and no monitoring systems, unreliable and in need of constant tinkering, dotted the hillsides of California, the result of a cutting-edge state tax credit. California’s utilities were unimpressed, the tax credit expired and wind went into a dormancy until European climate change concerns inspired incentives that drove the birth of the contemporary industry.

In today’s maturing wind industry, wind projects are small-business-sized- and big-business-sized power plants employing important numbers of people, more people, in fact, than the coal mining industry. To be built, projects require big manufacturing facilities for the assembly of the supply chain-provided 8,000 component parts, big construction crews with power mechanicals and cranes, and they require maintenance crews at an average rate of of 1 skilled technician per 10 megawatts of output.

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Today’s multi-megawatt turbines, with their power trains, controllers and condition monitoring systems, are almost as sophisticated as small airplanes. Hundreds of millions of dollars are staked on their effective performance. As a result, they must be and are far more reliable than the turbines that dotted California's hills a few decades ago. A productive wind project, i.e., a successfully operating business, can be run into ruin if its operations and maintenance costs suddenly go up due to turbine failures.

In traditional utilities, central plants have resident crews that do ongoing maintenance. Wind projects are dispersed. Their skilled technicians work at remote locations in small teams. Traditional utilities’ maintenance crews work in large plants with an array of in-place tools and multiple levels of supervision. Wind technicians work (at best) in pairs, in dangerously confined nacelle spaces or perched high on turbines or blades, many times in the severe weather conditions that wear at the machines and could provoke failures.

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The good news: Turbine failures don’t cause blackouts, toxic or radioactive spills.

The bad news: A turbine failure could be an idiosyncrasy or an announcement of pending troubles in the fleet.

Structural health monitoring is currently done in wind project turbines with commercially available condition monitoring systems. Maintenance crews combine these systems’ data with onsite findings to reach conclusions about the state and needs of the turbines. This maximizes maintenance efficiency and allows just-in-time repairs that minimize downtime so that the turbines can stay in service.

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Wind industry engineers are presently at work innovating software and information technology (IT) systems that will allow the technicians in the field to rapidly assimilate statistical data and indications of trends in the projects where they are doing maintenance or troubleshooting so as to determine whether they are dealing with an idiosyncratic breakdown or a fleet failure.

Aside from the advantage such innovation offers project operators, it is an indication of the level of skill and critical thinking required of the growing brigades of wind technicians. Extrapolating from this, it also suggests the increasing level of sophistication required of the armies of people that will design, manufacture and construct the coming convoys of wind projects the nation will build as it marches toward obtaining 20% of its electricity from wind power.

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The NREL paper narrowly focuses on stimulating creative thinking by wind engineers to answer the need for new turbine health monitoring systems for the next generation of wind plants.

Most of the growth of the modern wind industry happened in the last 10 years (1999-to-2009). By reaching an installed capacity of 25+ gigawatts, the U.S. regained world leadership but China is at its heels. The credit crunch has slowed the budding rebirth of the U.S. wind manufacturing sector whereas China continues to aggressively grow its turbine and supply chain manufacturing capability. Installation, operation and maintenance of plants have become the focus of U.S. developers seeking to control the costs of projects and the resultant cost of wind energy-generated electricity.

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The 2008 DOE study indicated there are no technological breakthroughs or discoveries of new wind sources necessary for wind to provide a fifth of U.S. power in 2 decades. The industry’s 9+ gigawatts of new installed capacity in 2009, twice what the timetable to reach 20% by 2030 calls for, verified DOE’s finding.

Building at a rate at which wind will achieve the 20% goal is expected to generate over half-a-million jobs in the next 2 decades.

Wind’s only apparent obstacle to achieving its goal would be if operation and maintenance (O&M) costs become too great, making the cost of operating wind projects so expensive that the electricity generated could not, as it does now, compete with the cost of fossil fuel-generated electricity. Out-of-hand O&M costs could cause that to happen. IT-managed turbine health monitoring and automated diagnostic systems would help skilled and experienced turbine maintenance teams hit the DOE-targeted $5 per megawatt-hour O&M cost and keep wind's growth on track.

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Present O&M costs are, on average, in the range of $10 per megawatt-hour and rise as turbines age and in turbines in regions with more forceful winds.

DOE’s estimate of wind’s 2030 potential includes 80 gigawatts of offshore wind capacity. Although the U.S. currently has no offshore projects, many believe its potential is significantly greater than the DOE estimate because winds are stronger and steadier over the ocean. Breakthroughs in IT-managed turbine health monitoring and automated diagnostic systems that cut O&M costs and increase reliability for turbines in the harsh offshore environment can have an even greater impact on rapid expansion of installed capacity.

High failure rates for turbine drivetrains and gearboxes make them the focus of more attention but health monitoring for them is presently workable. Blades and other components also require maintenance but there are no useful and cost-effective monitoring methods currently available for those parts of the system.

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The NREL paper concludes with several key observations:
(1) O&M costs remain one of the most costly factors for a wind industry that is rapidly becoming an important part of the world’s electricity generation;
(2) Present monitoring techniques address turbine drivetrain O&M costs;
(3) Further research is needed on structural health monitoring for blades and other major turbine components;
(4) IT systems are needed to assimilate and analyze wind project data where there is a failing turbine and diagnose implications pertaining to adjacent turbines; and
(5) Load estimators are needed to identify and track turbine-stressing conditions and work out the load-reduction strategies that would prevent turbine failures before they happen.

On its surface, the NREL paper appears pretty technical but just under its surface lurks a simple but crucial announcement that requires no engineering training to understand: Look to the wind industry for innovative, cutting-edge high-tech breakthroughs and hundreds of thousands of challenging, high quality jobs building the nation's future in the coming decades.

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QUOTES
- From the NREL report: “…wind turbines operate in very stochastic environments with dynamic loading. This makes damage rate prediction very difficult. Drivetrains are monitored today because of their notorious failure rates and cost to repair. Blades and other major components require unexpected maintenance as well, but they are not monitored. This is due to the lack of a cost-effective and viable monitoring method. There may be other health monitoring opportunities for wind plants…”

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- From the NREL report: “Wind energy installations are leading all other forms of new energy installations in the United States and Europe. In Europe, large wind plants are supplying as much as 25% of Denmark’s energy needs and 8% of the electric needs for Germany and Spain, who have more ambitious goals on the horizon. Although wind energy only produces about 2% of the current electricity demand in the United States, the U.S. Department of Energy, in collaboration with wind industry experts, has drafted a plan that would bring the U.S. installed wind capacity up to 20% of the nation’s total electrical supply. To meet these expectations, wind energy must be extremely reliable. Structural health monitoring will play a critical role in making this goal successful.”

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- From the NREL report: “One of the unique aspects of wind plants is the fact that there are many turbines in a single plant. They may be distributed over a large region but they will generally experience similar average wind speeds. An experienced operator can quickly detect when machines are operating in high-turbulence locations. These machines tend to experience high fault rates and can experience low production. They can also be chosen as the lead maintenance machines to watch and perhaps add additional instrumentation…Sometimes performance, control settings, and faults on adjacent turbines can be compared to detect anomalous faults. This technique can be quite powerful but always requires a skilled technician or engineer to investigate individual turbine behavior. This process is aided by the voluminous detailed data produced from the turbine SCADA system. However, for technicians to determine the best strategies for correcting problems and feel confident that they are fixing the right problem, they need expert systems…”