How do wind turbines generate electricity?

A wind turbine uses moving air to create electricity. Wind traveling across the blades creates lift — like an airplane wing — which drives a generator producing electricity. Electricity generated by utility-scale wind turbines is sent to the electric transmission system, where it displaces electricity that would otherwise have been generated by more traditional sources such as coal, oil, nuclear and natural gas.

Back to top

What is looked at when siting a wind farm?

Siting a wind farm requires three critical physical elements: wind, land and electrical infrastructure. There are also many individual factors or characteristics that are evaluated when selecting turbine locations, including:

• Wind: Sites with acceptable access to the wind resource are identified, taking into account land contour, elevation, prevailing wind direction, and accounting for a turbines impact on other turbines (wake losses) by using separation distances between turbines.
• Control of Land: Turbines must be located on property controlled by willing landowners.
• Setbacks: Areas are eliminated based on minimum setback distances to existing land uses such as houses, roads, and property lines.
• Microwave Communications: Worst Case Fresnel Zone areas are eliminated.
• Airports: Any Cone of approach areas would be eliminated.
• Natural Environment: Areas to be avoided, if possible, include wetlands, waterways, any threatened and endangered species/habitat, historical and archaeological resources, and forested lands.
• Resource Preservation: Any lands under the Farmland and Ranch Preservation Program (FRPP), Managed Forest Law (MFL) and the Conservation Reserve Program (CRP). These areas are considered based on their compatibility with wind farm facilities.
• Auxiliary Facilities (Cable routes, access roads and crane routes): In identifying turbine sites, the following goals and characteristics are considered — least impact to the land; avoidance of wetlands, forests, and structures; minimum distance to the interconnection point; and efficient construction.

Back to top

What is the anticipated life of a wind farm?

The design life is generally 30 years.

Back to top

What happens after 30 years?

With proper maintenance, the wind turbines can operate beyond 30 years. However, new technologies may exist that may make it economic to replace the turbines or the decision could be made to decommission the wind turbines. Decommissioning focuses on removal of turbines and towers and includes removal of concrete foundations to four feet below grade. Other features such as the operations/maintenance building may remain and be used for other purposes. Underground cables are left in place (after being cut off well below grade) because removing them would cause more disruption to the land than abandoning them in place. The land used for the wind turbines and associated equipment will be restored to its original condition. Roads, at the landowner's request, may be left intact. Restoration typically includes grading and replanting areas where foundations, roads, and buildings were located.

Back to top

What type of approvals do you need to begin constructing a wind project?

As a regulated utility, We Energies is required to obtain authorization from the Public Service Commission of Wisconsin (PSCW) before it can construct a project. In addition, we work with the local communities and numerous other agencies including: Wisconsin Department of Natural Resources, Federal Aviation Administration (FAA), Wisconsin Department of Transportation, U.S. Fish and Wildlife Federation, U.S. Army Corp of Engineers, Wisconsin State Historical Society and National Heritage Inventory.

Back to top

Why do some of the turbines have lights on the top of them?

The Federal Aviation Administration (FAA) requires the turbines around the perimeter of the site to have a red reference beacon. At Blue Sky Green Field Wind Energy Center, the FAA determined that out of the 88 turbines in the project area, 35 of them are required to have lights. In addition, the three meteorological towers in the project also have the required FAA lights.

During construction, We Energies is required to provide the FAA with notification on each erected turbine including the location, height, and distance from the nearest airport and when the lighting will be activated. The FAA then uses this information to create a Notice to Airman (NOTAM), which is a notice that is issued to pilots during pre-flight briefings to ensure they have the essential information for safe flight.

Back to top

What can you hear from the turbines?

The sounds generated by wind turbines are from: the blades rotating in the air, the gearbox located inside the nacelle and the yaw motors used to occasionally rotate the nacelle into the direction of the wind.

A pre- and post-construction study was conducted at our Blue Sky Green Field site to show the impacts of the turbines. The study concluded that the sound level is in compliance with the standards in the project permits and will not exceed 50 decibels audible (dBA) at a distance of 1,000 feet.

When considering the results described above, some context for dBA is helpful. As a point of reference, the typical sound levels for a conversation is around 60 dBA and a quiet office is approximately 50 dBA. Wind turbines typically operate quiet enough to hold a normal conversation at the base of the machines, and it is fairly common for the natural noises generated by the wind to drown out the sound from wind turbines.

We Energies has contracted with Hessler & Associates to conduct a pre- and post-construction sound study to show the potential impacts of the turbines at the Glacier Hills Wind Park site.

Back to top

Are there any health concerns in relation to wind turbines?

There are no proven findings connecting wind turbines and adverse health conditions. Over the past decade, wind turbines have safely been used in the United States, Germany, Denmark and the United Kingdom.

Back to top

Is there any danger of ice falling or being thrown from the wind turbines?

The ice that can form on a wind turbine is very similar to the thin sheet of ice that can form on utility poles, communication towers and power lines. Many times a wind turbine will shut down if ice forms on the blades as a result of the ice slowing down the rotation of the turbine. The ice will most likely melt off by the heat of the sun or from an increase in temperature. In the rare occurrence that the ice does not melt, pieces of ice can fall around the base of the turbine.

Back to top

Why do the turbines not spin at times?

The most common reason that turbines stop spinning is because the wind is not blowing fast enough. Most wind turbines need a sustained wind speed of 9 MPH or higher to operate. Technicians will also stop turbines to perform routine maintenance or repairs.

Back to top

Can wind turbines interfere with television and radio reception?

Wind turbines can interfere with television and radio signals received through an antenna. However, given the distances between wind turbines and homes or businesses, the turbines do not interfere with satellite technologies because the signal is received from above rather than from a land-based broadcasting tower.

In the event that signal interference from wind turbines is experienced, We Energies is committed to resolving the issue and covering the costs. We have employed a variety of technologies and techniques in the past to mitigate the issue. For example, at our Blue Sky Green Field Energy Center we have established a program to restore the local channels for those experiencing problems as a result of the turbines. The program includes an evaluation of the resident's situation and applying the right solution. In some instances, the solution includes servicing an antenna, installing a different antenna or replacing components of the antenna system. If the antenna adjustments do not resolve the matter, the hardware and local programming for satellite service is provided.

There have also been instances where residents have experienced interference with FM radio reception. After evaluation, we have found that a commercially available HD radio is capable of clearing FM reception, and we will work with impacted landowners to provide this equipment.

Regardless of the technologies used to restore television or radio interference caused by our wind turbines, We Energies is committed to providing a remedy for as long as the turbines are operating.

Back to top

What type of shadows do the wind turbines cast?

Wind turbines, like any large object, will cast shadows that will extend further at dusk and dawn when the sun is low on the horizon. The shadows cast by the wind turbines will vary with several factors including season, time of day, surrounding terrain, cloud cover, wind speed and direction.

Shadow experienced at any particular location will vary depending on the position relative to a turbine, wind speed, wind direction, natural or man-made obstructions, season and cloud cover. The number of hours of shadow per year decreases and the shadows become more diffused (i.e. not as bold or contrasting) with increasing distances from a turbine. For example, if a home was located approximately 1,200 feet from a turbine and there were no other natural or man-made obstructions, it may experience approximately 25 hours of shadow per year. However, if the home were to the south of the turbine, the sun would not be in a position to create a shadow.

Back to top

Will emergency helicopters respond to emergencies within the wind farm?

We Energies' number one priority is always safety. A common misconception exists regarding the use of emergency-helicopter services within a wind farm. At our Blue Sky Green Field Energy Center this issue was also raised. At that location, the local communities and emergency responders established emergency response plans that include pre-designated landing zones for both Flight for Life and Theda Star emergency helicopter services.

Emergency responders have informed us that there is no prescriptive rule dictating that an emergency helicopter cannot land near a turbine. It is within the purview of each respective pilot to make that determination based on all of the variables presented at the site. As may be the case due to any nearby tall structure, building, power lines, trees or even a silo; a helicopter cannot always land at the actual scene of an accident. It is common for helicopter pilots to land in the immediate vicinity in coordination with the direction of emergency personnel on the ground. In addition to the variability of the immediate surroundings, weather and surface conditions play an important role in determining where a medical-helicopter pilot may decide to land. The pre-designated, nearby landing zones are mapped and have been communicated to both air-ambulance services.

We have also provided training to responders for specific emergency response to the turbines, and have funded the specialized equipment required for their use. In meetings and discussions with the emergency responders for our Blue Sky Green Field site, we have been assured they have a plan for emergency response within the project area, and are comfortable that it appropriately addresses the public safety as well as that of our employees working in the area. It is important to note that each turbine is permitted through the Federal Aviation Administration and Wisconsin Department of Transportation.

Back to top

Do the local communities that host wind turbines receive payments?

Yes, state law specifies shared revenue compensation for the communities hosting generation facilities. The State of Wisconsin, through its utility shared revenue program, provides payments of state funds to local counties and municipalities that host generation facilities. These payments are based on the size of the facility. In addition, the State provides supplemental payments for baseload plants of 50 MW or larger and for renewable resources.

The annual utility shared revenue payments are currently based on $2,000 per MW, which is $300,000 per year for a 150 MW project. The town(s) receives 1/3 of this amount and the county receives the other 2/3. In addition to this base payment, every new generating facility that is powered by an alternative fuel generates an additional payment of $1,000 per MW for both the town and county. Applying this premium in the example, the towns and county in aggregate would receive $600,000 per year under the current utility shared revenue formulas.

Back to top