The English Farms wind farm is being built in Deep River and Jackson Townships, approximately 96km east of Des Moines in Poweshiek County, Iowa. The 170MW farm is expected to be fully operational in March 2019.
The wind farm development forms part of a $1.8bn expansion project for adding up to 1GW of wind production capacity across Iowa to power up to an additional 430,000 Iowa homes a year.
The English Farms wind farm was acquired by Alliant Energy from the developer Tradewind Energy, in December 2017. Alliant will also offtake the power generated from the wind farm for utility distribution.
The wind farm will supply green power to approximately 50,000 homes when fully operational in 2019. It will bring $250m investment in the form of infrastructure developments and create more than 100 temporary jobs during construction and up to 12 permanent jobs during operations.
English Farms wind farm location
The project area of the wind farm extends over 19,675 acres within 38 sections, mainly comprising agricultural land, in Poweshiek County. The area offers a robust wind resource and existing on‐site electrical infrastructure for interconnection to the grid at the interconnection substation.
Of the total land area, the plots represented by Participating Properties in the Project Area (approximately 15,180 acres) are sufficient to develop the project.
Wind turbine details
The project will feature 68 wind turbines including 59 GE 2.5-127 turbines and nine GE 2.3-116 turbines.
GE’s 2.5MW, 127m turbine generator ensures class-leading capacity factor and enhanced annual energy production (AEP) in the 2MW class for lower wind speeds.
The GE 2.3MW-116m wind turbine has a rotor swept area of 10,660m² and an AEP rating of 11,832MWh at 8m/s.
Each wind turbine will sit atop a concrete foundation having a diameter of approximately 60ft and a depth of up to 12ft.
The maximum nominal rotor diameter of the wind turbines is 116m. The turbine’s rotor and nacelle are mounted on top of a tubular steel tower. The hub is attached to the nacelle, which houses the generator, brake, cooling system, and other electrical and mechanical systems.
The 2MW-116 and 2MW-127 turbines use passive and active yaw control systems respectively, to rotate the nacelle of the turbine towards the direction of the wind.
Lightning and ground protection for all the equipment and systems of the wind farm are also being installed. Grounding and shielding components will be integrated into the foundation and structural elements of all the equipment and conductor lines.
A new substation at the project site is being designed to step‐up the voltage from 34.5kV to 161kV. The project substation will integrate metering equipment, collection system, and power regulation and protection systems.
The wind farm will be linked to the existing Parnell‐Poweshiek 161kV grid owned by MidAmerican Energy.
A new interconnection substation will also be constructed next to the existing 161kV transmission line within the project area. Owned and operated by MidAmerican, the interconnection substation will be connected to the project substation by a new overhead line to be built as part of the project.