Project to be largest in world if built out to full capacity SIOUX FALLS, S.D., Aug. 5 /PRNewswire-FirstCall/ -- BP Wind Energy and NorthWestern Energy (NYSE:NWE) today welcomed South Dakota Governor Michael Rounds at a wind turbine blade signing event to celebrate the move into full construction of the Titan I Wind Farm in Hand County, South Dakota. Governor Rounds, who was joined by other state and local elected officials, landowners and community leaders said: "Today marks an important step in delivering clean power from a renewable resource, and that's a credit to innovative thinking and planning by the partners in this project. South Dakota has tremendous potential to become a leader in wind energy development, and utilization of this abundant natural resource harbors the potential of great economic promise for the state." Located on a 7500-acre site south of the town of Ree Heights, the Titan I Wind Farm is 100% owned by BP Wind Energy with the energy sold to NorthWestern Energy for use by its customers in South Dakota. Phase I will utilize 10 Clipper C89 wind turbines each with a rated capacity of 2.5 MW. The project will employ up to 175 workers during peak construction and is expected to be in commercial operation in the first quarter of 2010. The balance of the plant contract has been awarded to Mortenson Construction. "BP's approach to meeting America's future energy needs includes oil, natural gas and significant investments in alternative energy such as wind power, as this project demonstrates," says John Graham, president, BP Wind Energy. "Large wind farms such as Titan are the long-term future of the wind energy business but to deliver on this opportunity, we have to address the transmission challenges and we commend those who are actively working to enable South Dakota to reach its full wind development potential," adds Graham. "We take seriously our responsibilities to the environment and to our customers," says Bob Rowe, president and CEO, NorthWestern Energy. "This wind farm will provide approximately 5% of the total energy supply used by our South Dakota customers. This is good both for the environment and for the local economy. We're committed to evaluating future options that will provide value to customers while helping to grow this industry for the benefit of all South Dakotans." The first phase of the wind farm will tie into an existing above-ground 69 kV NorthWestern Energy transmission line. When in full operation, the Titan I Wind Farm will generate enough carbon-free electricity to power 7500 average American homes. Media Inquiries: Tom Mueller, BP Press Office: 281-366-1236 Tom Glanzer, NorthWestern Energy: 877-410-0154 About BP Wind Energy/BP America BP Wind Energy is a wholly owned subsidiary of BP, one of the world's leading energy companies. BP Wind Energy currently has interests in six operating wind farms: the 400 MW Fowler Ridge I project in Indiana; the 300.5 MW Cedar Creek project in Colorado; the 100 MW Flat Ridge I project in Kansas; the 20 MW Edom Hills project in California; and the 150 MW Sherbino I project and the 60 MW Silver Star I project, both in Texas. In the past month, the company has announced it has moved into construction of Phase II of the Fowler Ridge Wind Farm in Indiana which will have a generating capacity of 200 MW and is expected to be in commercial operation in the first quarter of 2010. BP America is the largest producer of oil and gas in the United States and one of the nation's largest energy investors. For more information, visit the company's Web sites at http://www.bpalternativenergy.com/ and http://www.bp.com/us. About NorthWestern Energy NorthWestern Energy provides electricity and natural gas in the Upper Midwest and Northwest, serving approximately 656,000 customers in Montana, South Dakota and Nebraska. More information on NorthWestern Energy is available on the Company's Web site at http://www.northwesternenergy.com/. DATASOURCE: NorthWestern Corporation CONTACT: Tom Mueller, BP Press Office, +1-281-366-1236, or Tom Glanzer of NorthWestern Energy, +1-877-410-0154 Web Site: http://www.northwesternenergy.com/ http://www.bpalternativenergy.com/ http://www.bp.com/us

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