Wind Power's Three Es
Wind energy impacts the economy, environment, and employee safety in significant ways.
Wind-generated energy has taken the country by storm, partially because of government programs and subsidies and partly due to the pursuit of clean energy sources to reduce pollution. In fact, the recently released 2011 Wind Technologies Market Report from the U.S. Department of Energy (DOE) claims the U.S. wind energy market accounted for $14 billion of new investment in 2011 and supports tens of thousands of jobs.
Wind Energy and the Economy
According to the report, in 2011 roughly 6,800 megawatts (MW) of new wind power capacity was added to the U.S. grid, a 31 percent increase from 2010. Wind power capacity rose to 47,000 MW by the end of 2011 and has now grown to 50,000 MW. DOE says that’s enough electricity to power 13 million homes each year -– or all the homes in Nevada, Colorado, Wisconsin, Virginia, Alabama, and Connecticut combined. Overall, installed wind energy capacity for the country grew 16 percent from 2010.
Some of the increase in energy capacity can be attributed to technical innovations that have allowed for larger wind turbines and longer, lighter blades. These innovations have increased the efficiency of power generation and improved performance overall. Because wind project capital and maintenance costs are declining at the same time, wind energy is competitive with a range of other power sources.
Two other recently released reports, both from the Natural Resources Defense Council (NRDC), tout the benefits of wind farms to the U.S. economy. "At Wind Speed" claims that for every wind farm constructed in the United States, more than 1,000 jobs are added and tens of millions of dollars in new taxes and benefits flow to the surrounding community. The second report, "American Wind Farms," breaks down the types of employment created during the building of a wind farm into non-construction and construction jobs. The report further explains that a typical wind farm will add 432 manufacturing, 80 planning and development, 18 sales and distribution, and 27 operation and maintenance positions. Construction jobs account for 273 on-site civil workers for heavy construction, 202 wind turbine installers, and 47 on-site electrical workers, the report shows.
In total, government statistics indicate the wind sector employs roughly 75,000 workers, including workers at manufacturing facilities, engineers, construction workers, and wind farm operators.
Wind Energy and the Environment
The push for the expansion of wind energy comes as concerns over air pollution and climate change grow. Wind power has obvious benefits for the environment, including a much lower carbon footprint than fossil fuel power plants. Because wind turbines don't use combustion to generate electricity, they don’t produce polluting air emissions. While turbine machinery does rely on lubricating oils and hydraulic and insulating fluids, these are used only in small amounts and are unlikely to present risks to the surrounding land or waters.
Of course, there are concerns about how wind turbines may negatively affect the environment and human health. Government agencies such as EPA and the Bureau of Land Management (BLM) are studying the ways wind turbines affect wildlife, especially birds and bats; noise pollution; and the potential negative effects of flickering lights caused by the rotating blades. However, proper siting of individual turbines and wind farms may mitigate most of those concerns. EPA and the BLM are studying ways to prevent bird and bat mortality through siting wind farms in areas where they won't affect bird or bat migration routes.
Issues such as noise pollution and flickering lights can be addressed by siting the farms in less-populated areas. One strategy the BLM is exploring is siting fewer turbines in any one location by using multiple locations and using larger, more efficient models of wind turbines.
Another novel strategy that EPA is pushing involves siting wind farms on former hazardous waste sites. EPA, in collaboration with the National Renewable Energy Laboratory (NREL), has been looking at new ways to screen otherwise-unusable locations for their wind energy potential. The screening process places emphasis on the redevelopment of "potentially contaminated lands" or underutilized sites. Sites for consideration include brownfields (abandoned commercial or industrial sites), Superfund sites (contaminated sites), abandoned parcels, landfills, and mining spaces, to name a few. The advantage to using these sites is twofold: First, it "reuses" land that would be difficult to rehabilitate in other ways; second, it conserves green spaces where wind farms might otherwise be located.
Of course, there are problems with the approach, too. "Potentially contaminated" sites are areas where the land may be contaminated with hazardous wastes and materials. Communities and developers must conduct a site characterization and investigation before erecting any turbine and can build only on areas that have undergone remediation.
Wind Energy and Employee Safety
As the sails of the wind energy industry begin to fill, new challenges also begin to emerge. With roughly 75,000 workers now employed in various aspects of the wind sector, safety becomes a prime concern. While many aspects of siting, erecting, maintaining, servicing, and possibly deconstructing wind towers and turbines are unique, most job hazards these workers face are not.
Wind energy is a relatively "new" industry, and some of the employees may not be fully aware of the hazards in this work environment. With that said, wind energy employers are required by OSHA to protect their workers from workplace hazards. In addition, employees should be engaged in workplace safety and health and need to understand how to protect themselves from these hazards.
There are separate OSHA regulations that govern the safety of workers during the construction of the tower (29 CFR 1926) and during maintenance work (29 CFR 1910). Some of the hazards that workers in the wind energy industry may face are described below.
- Falls. One of the most obvious hazards associated with working on wind turbines is falls, which can occur during the construction and installation of the tower or during maintenance. During construction work, any time an employee is exposed to fall distances of 6 feet or more, he or she must be protected by guardrails, safety nets, or personal fall arrest systems. When construction is complete, employees often may have to climb to the nacelle (the cover that houses all of the generating components in a wind turbine, including the generator, gearbox, drive train, and brake assembly) to perform maintenance work. OSHA considers maintenance to be general industry work, so the 4-foot fall distance is the threshold where fall protection must be provided. Typically, this fall protection is in the form of a guardrail on a platform, or if that is not possible, then a personal fall arrest system.
- Climbing fatigue/ladders. Climbing the fixed ladders inside the wind turbine to the nacelle can take a toll on employees. OSHA requires these ladders to have either a safety cage or a ladder safety device. While climbing a fixed ladder exceeding 20 feet in length on these towers, a ladder equipped with a cage or well must have a landing platform every 30 feet; a ladder not so equipped must have a landing platform every 20 feet. Ladder safety devices may be used on wind tower ladders more than 20 feet in unbroken length in lieu of cage protection. No landing platform is required in these cases.
- Crane, derrick, and hoist safety. Cranes, derricks, and hoists are often used to move the large, heavy loads during wind turbine installation and maintenance. This equipment must be inspected before use and operated according to the manufacturer's instructions. The proper clearance distance from power lines must be maintained so the crane boom, load line, or load itself does not contact nearby power lines. Other crane hazards are present in the form of workers being struck by the load, caught inside the swing radius, or failing to assemble/disassemble the crane properly. There are significant safety issues to be considered, both for the operators of the lifting devices and for employees who work near them.
- Respiratory protection. Maintaining turbine blades may involve operations such as buffing and resurfacing, which may expose employees to harmful gases, vapors, and dusts. Workers must be protected from the inhalation hazards through the use of ventilation. If the ventilation alone is not adequate, then workers may also need to use appropriate respirators. Use of respirators may give a false sense of security and workers should understand the limitations of the respirators. For example, during heavy exertion the respirator seal is often compromised, which allows the chemical to enter the breathing zone (without being filtered) through the gaps between the respirator and the wearer’s face. It's essential that workers be trained in the proper use of respirators, including proper storage and maintenance.
- Fires. Workers may be exposed to fire hazards because of electrical equipment, combustible materials used in construction of the turbine, or lubricants involved in its operation. Wind energy employers should train workers about fire hazards at the worksite and about what to do in a fire emergency. This plan should outline the assignments of key personnel in the event of a fire and provide an evacuation plan for workers on the wind turbines. Wind turbines should be provided with quick escape descent devices for workers to escape in the event of a fire or other emergency.
- Confined spaces. A confined space is defined as an area that has adequate size and configuration for employee entry, has limited means of access or egress, and is not designed for continuous employee occupancy. The configuration of all nacelles will classify them as confined spaces. Some hazards may be severe enough to classify a nacelle as a permit-required confined space (PRCS). A PRCS is a confined space that presents or has the potential for hazards related to atmospheric conditions (toxic, flammable, asphyxiating), engulfment, configuration, or any other recognized serious hazard. If workers are expected to enter a PRCS, the employer must develop a written permit-required confined space program and make it available to workers. The program must detail the steps to be taken to make the space safe for entry.
- Electrical. Employees at wind farms are potentially exposed to electrical hazards, such as arc flashes, electric shock, falls due to shock, and thermal burn hazards. These hazards can occur inside the turbine itself or at nearby overhead power lines. OSHA requires employers to implement the safe work practices and worker training requirements in the Electric Power Generation, Transmission and Distribution standard (29 CFR 1910.269).
- Machine guarding. Additionally, the moving parts associated with the turbine (such as gears and blades), if not guarded properly, have the potential to cause severe injuries, such as crushed fingers or hands, amputations, burns, or blindness. Employers must ensure that the workers are protected from these hazards, and workers must make sure that the rotating parts and points of operation of machines are properly guarded prior to using them.
Winds of Change
While no one knows which way the wind will blow for the wind energy sector, whether the industry will continue to grow or is going to stall, it has already made a significant impact on the economy, the environment, and the employees who work in it. Wind power has the potential to alter the landscape from smokestacks to turbines, from "dirty" sources of energy to clean energy generation. With proper siting and careful attention to safety, wind energy may well weather the winds of change.
Lisa Neuberger is Editor, Workplace Safety, with J.J. Keller & Associates Inc. She specializes in workplace safety and environmental topics for Industrial Markets Publishing at J.J. Keller & Associates and covers solid and hazardous waste, safety committees, sanitation, OSHA injury and illness recordkeeping, and many other related topics. In addition to the J.J. Keller publications she writes for, her work has also appeared in industry trade publications read by safety and environmental professionals.
Mark H. Stromme is a Workplace Safety Editor and an authorized OSHA Outreach Trainer for Construction. He also specializes in oil and gas industry safety and regulatory compliance.