Boswell Energy Center Unit 4 to Reduce Mercury Emissions by 90 Percent, Extend Reliability and Continue to Provide Cost

  Boswell Energy CenterUnit 4to ReduceMercury Emissions by 90 Percent,
  Extend Reliability and Continue to ProvideCost-Competitive Energy

Business Wire

DULUTH, Minn. -- May 08, 2012

The region’s largest electric generating unit will undergo a major
environmental retrofit that will greatly reduce emissions while helping to
ensure competitively-priced energy for decades to come.

Boswell Unit 4 in Cohasset, Minn. will reduce emissions of mercury,
particulates and sulfur dioxide. ALLETE Chairman, President and CEO Al
Hodnikmade the announcementtoday at ALLETE’s Annual Meeting of Shareholders.

“This capstone event ofoursix-year environmental control effort will
transform Boswell 4, the workhorse of our generation fleet,so it continues to
provide reliable, safe and affordable electric power to our customers,” Hodnik
told ALLETE shareholders at the Duluth Entertainment Convention Center.
Minnesota Power, based in Duluth, isautility division of ALLETE, Inc.(NYSE:

Boswell Unit 4 is capable of producing 585megawatts of electricity. Minnesota
Power owns 80 percent of Boswell 4 with the balance owned by WPPI Energy.
Minnesota Power’s portion of the project is estimated to be $350-400 million
over the next several years. WPPI Energy will pay the cost of its share of the
project. Multi-emissionreduction project plansandpermitapplicationswill
be filed with federal and state regulators next month.

With requirements for a 90 percent mercury reduction on Boswell Unit 4 by 2018
already in state statute, Minnesota Powerhas been analyzing a Unit 4 retrofit
as pending Environmental Protection Agency regulations affecting coal units
across the nation are finalized. Technology choices, resource needs, economic
projections, customer cost impacts and project execution were key factors in
this extensive assessment. TheEPA’s issuance of the MATS Rule for mercury
reduction in December of 2011 was a key factor in the timing of Minnesota
Power’s decision.

Over the past six years, Minnesota Power has invested approximately $350
million dollars to reduce emissions by about 70 percent overall on its system,
with most of this investment applied to Boswell Unit 3, the company’s second
largest generator. The Boswell 4 project will increase overall emission
reduction to around 85 percent. Every phase of Minnesota Power’s ongoing
resource planning process has underscored that emission reduction investments
in Boswell 3 and 4 to enhance and sustain these core energy sources are a good
value for customers.

“We can use cost-effective technology to greatly reduce emissions and keep our
largest and newest base load plants operating for many more years,” said
Hodnik. “This will allow us to serve the growing energy needs of our customers
economically and reliably, while meeting our environmental responsibilities.
The Boswell 4 emission reduction project is another example of our commitment
to enhance the economy and quality of life in this region.”

In conjunction with achieving greatly reduced emissions and increased
operating efficiencies in its coal-fired fleet, Minnesota Power also is adding
considerable cost-effective renewable energy to its portfolio. The
companywillmeet future energy needs with a more diverse, lower-emitting
power supply that lessens coal-fired generation to about 50 percent of its
total resource base. This transition to significantly reshape Minnesota
Power’s fleet is well underway and will be facilitated by the Boswell 3 and 4
reinvestments and through previously announced major additions of wind energy
and hydro power.

Minnesota Power, a division of ALLETE, Inc., supplies electric service to
144,000 residents, 16 municipalities and some of the largest industrial
customers in the United States. More information can be found at

The statements contained in this release and statements that ALLETE may make
orally in connection with this release that are not historical facts, are
forward-looking statements. Actual results may differ materially from those
projected in the forward-looking statements. These forward-looking statements
involve risks and uncertainties and investors are directed to the risks
discussed in documents filed by ALLETE with the Securities and Exchange


Minnesota Power/ALLETE
Amy Rutledge, 218-723-7400
Manager - Corporate Communications
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