The Whispering Willow Wind Farm-East is located in Franklin County, in north central Iowa. It began commercial operation in December 2009. A second phase – the West phase – could be added as economic conditions allow.

Whispering Willow East consists of 121 turbines capable of generating up to 200 MW of emissions free energy, enough power for approximately 50,000 homes. If the West phase is added in the future, the Whispering Willow Wind Farm has the potential to produce up to 500 megawatts. As a result, the wind farm will be capable of powering approximately 125,000 Iowa homes.

Currently, the wind farm employs nearly 30 people directly and indirectly through contracts. Many of the people live in nearby towns and cities bringing valuable economic activity to the area. Property taxes for the wind farm will be phased in over time which will bring even more benefit to the community.

With the East Phase completed, approximately 6 percent of IPL’s electricity comes from renewable energy sources through a combination of purchased power agreements and other company-owned renewable facilities. Eventually it is expected that more than 90 percent of IPL’s renewable energy will come from wind power.

Wind Farm Facts | Photos | Map | Frequently Asked Questions

Whispering Willow Wind Farm-East Facts

• The East farm spans approximately 33,000 acres or approximately 51 square miles
• The towers are tubular and made of rolled steel. The blades are made of fiberglass–reinforced polyester or wood epoxy.
• Each wind turbine is capable of producing approximately 1.65 megawatts, the equivalent of powering approximately 400 homes
• The concrete foundation support is approximately 50 feet wide by 7 feet deep. This requires more than 450 cubic yards of concrete, which equals approximately 30 concrete mixing trucks
• Height of the wind turbines is nearly 400 feet from the ground to the tip of the blade when a blade is straight up
• Distance from the ground to the ‘hub’ is approximately 262 feet
• The length of each blade is 131 feet
• Each blade weighs 15,000 pounds
• The nacelle weighs 104,000 pounds
• The hub weighs 42,000 pounds
• The total weight of each turbine including the tower, hub and blades is more than 450,000 pounds.
• Power generation begins at 9 miles per hour with a maximum power generation of 27 miles per hour
• The wind turbines can produce power approximately 90% of the time, depending upon sustainable wind speeds and electric grid needs

Photos

Whispering Willow Wind Farm photos - 10/09

Whispering Willow Wind Farm photos - 8/5/09

Map
Whispering Willow Wind Farm Map [PDF]

Frequently Asked Questions

Whispering Willow Wind Farm

When did IPL purchase the development rights to Whispering Willow wind farm?
December 2007

Why was IPL interested in this site?
Alliant Energy believes in preparing for our customers’ and Iowa’s energy future. Our company is committed to maintaining our strong renewable presence in the State of Iowa. The Whispering Willow Wind Farm is located in the center of our state’s ‘wind belt’, which means that the wind will generate electricity for our customers more consistently than in other parts of Iowa.

How much electricity will be generated by Whispering Willow Wind Farm?
Whispering Willow will generate approximately 200 megawatts of electricity each year, or enough to power approximately 50,000 homes.

How many turbines are at Whispering Willow Wind Farm?
Whispering Willow Wind Farm Phase 1 will have 121 Vestas V82 turbines.

Where is the wind farm site and where will the turbines go?
The wind farm site is located in north central Iowa and spans portions of Franklin County, Iowa.

What type of agreement exists between the landowners and IPL?
Landowners who are hosting a wind turbine signed agreements providing a long-term, stable source of income for property owners. This is also a finanicially viable project for IPL.

What type of turbine is used at Whispering Willow Wind Farm?
Vestas V82 wind turbines are used at Whispering Willow Wind Farm. Each of the turbines is capable of producing 1.65 megawatts of electricity.

Are there IPL employees present at Whispering Willow Wind Farm?
Approximately 18-25 full-time staff are necessary for the operation of the Whispering Willow Wind Farm. These employees are a combination of management, engineering, technicians and administrative staff.

What type of lighting is used around the wind turbines?
There is no base-level lighting on or around the wind turbines. The only lighting on the wind turbines is the mandatory FAA lighting on the top of the wind turbine to alert aircraft.

Do the wind turbines produce noise?
Wind turbines only produce measurable noise when they are operating, but it is not disruptive to most people in most situations. Today, an operating wind farm at a distance of 750 to 1000 feet is no noisier than a modern kitchen refrigerator. You can stand directly beneath a turbine and have a normal conversation without raising your voice.

Are the landowners still be able to use the land around the wind turbines?
With the exception of a 50’ x 50’ parcel directly surrounding the wind turbine’s base and a narrow access road, landowners will be able to utilize all the land surrounding the wind turbine. Many farm roads can double as access roads, reducing non-usable land even further.

Costs and Economic Impacts

What did Whispering Willow cost?
Phase 1 will cost more than $400 million.

How does Whispering Willow Wind Farm help the economy in Franklin County?
“Shared revenue” payments are made each year to the city, village, or township and the county in which the facility is located.

There are also anticipated increased revenues to local businesses (hotels, restaurants, gas stations) during the construction phase of the project.

Environment

What are the environmental benefits of wind power?
Wind power benefits the environment because it does not create any emissions or deplete natural resources, such as wetlands and animal habitats.

How will Whispering Willow Wind Farm benefit Iowa’s environment?
By offsetting the need for traditional fossil fuel generation, Whispering Willow Wind Farm will help Iowa’s environment. When completely developed, Whispering Willow Wind Farm will reduce IPL’s system-wide annual emissions:

• Sulfur dioxide (S02 )reduced by approximately 1,500 tons
• Nitrogen Oxide (NOx) reduced by approximately 650 tons
• Mercury (Hg) reduced by approximately 30 pounds
• Carbon Dioxide (CO2) reduced by approximately 472,000 tons, which is equivalent to:
• • Removing nearly 75,000 cars from the road for one year
  • Accumulating electric energy savings equal to powering 35,000 homes for one year

Does Whispering Willow Wind Farm harm birds or bats?
The impact of wind farms on birds or bats is mostly determined by flight patterns of birds and bats in the area and a review of natural resources which could serve as habitats for avian wildlife. In order to determine any potential impacts to birds and bats, a risk analysis was completed during the early project planning stages and a preconstruction bird survey was conducted in the fall of 2008. It was determined the project site is a low-risk for bird and bat mortality.

What additional environmental assessments were conducted for the Whispering Willow Wind Farm?
An analysis of impacts to threatened and endangered species was conducted at the wind farm site. This review concluded that minimal or no impacts to any threatened and endangered species will occur since most land in the project area is already being used for intense row crop production and there is a lack of suitable habitat.

Also, further environmental studies indicate that the wind turbines should not impede upon the natural habitat of other animals, such as deer, rabbits, and should not disturb wetlands areas or historic archaeological sites.

Whispering Willow Wind Farm Project Timeline

When was the wind farm built?
Construction of Whispering Willow began in December 2008 and became operational in December 2009.