Silver+ Saturday – ALLETE Clean Energy’s newest wind facility goes online to power Upper Midwest

Company expands wind fleet with addition of 106-megawatt Glen Ullin Energy Center in North Dakota DULUTH, Minn.– ALLETE Clean Energy, a wholly owned subsidiary of ALLETE (NYSE: ALE), announced today that its Glen Ullin Energy Center about 40 miles west of Bismarck, North Dakota, is now online and producing wind power for Xcel Energy customers in the Upper Midwest. Glen Ullin Energy Center, a 106-megawatt wind facility, produces enough electricity to power about 55,650 homes from its 43 2.3- and 2.5-megawatt General Electric turbines. It will employ about 10 people during operation, and provide property tax and other business benefits to area communities and lease payments to landowners. “Today our team celebrates completion of the latest wind site that ALLETE Clean Energy has developed, built, and will own and operate,” said ALLETE Clean Energy President Allan S. Rudeck Jr. “I would like to thank the North Dakota policymakers and area landowners who supported this investment. North Dakota’s ‘all-of-the-above’ energy policy strengthens local economies through projects like Glen Ullin and has made the state a national energy leader.” “Wind energy in the Upper Midwest will help us deliver low-cost, carbon-free electricity to our customers and is part of our plan to reduce carbon emissions 80 percent by 2030,” said Chris Clark, president of Xcel Energy-Minnesota, North Dakota, South Dakota. “As a wind energy leader for more than a decade, projects like Glen Ullin bring investments to North Dakota while also keeping bills low for our customers.”

Glen Ullin Energy Center is the third North Dakota wind expansion project developed and built by ALLETE Clean Energy, and the first it will own and operate. It also developed the 107.5-megawatt Thunder Spirit wind farm near Hettinger and sold it to Montana-Dakota Utilities in 2015. ALLETE Clean Energy expanded Thunder Spirit to about 155 megawatts and sold the expansion to MDU in 2018. According to recent research, ALLETE is ranked the second-largest investor in renewable energy in the U.S. and Canada as a percentage of market capitalization. “This successful project signifies ALLETE’s commitment to continued investment in North Dakota as we increasingly focus on developing carbon-free energy solutions,” said ALLETE CEO Al Hodnik. “ALLETE sees limitless opportunities for growth, not only in North Dakota’s world-class energy resources but also across the United States. Our talented employees continue to answer the call to transform the nation’s energy landscape by working together with officials and landowners in a number of states and through agreements with Manitoba Hydro in Canada.”

ALLETE Clean Energy is working on the 80-megawatt South Peak wind site in Montana with plans to bring it online near the end of the year to sell power to NorthWestern Energy. The company’s approximately 300-megawatt Diamond Spring wind project in Oklahoma has broken ground and will sell wind power to Walmart, Starbucks and Smithfield Foods. It is ALLETE Clean Energy’s first project to sell wind power to corporate customers, and will come online in late 2020 as the company’s largest wind site. ALLETE Clean Energy’s purchase of wind turbines that qualify for the safe harbor provision of federal production tax credits enable the Glen Ullin project’s low energy costs. In addition to turbines installed at Glen Ullin, ALLETE Clean Energy retains more safe harbor turbines for additional wind site development. ALLETE Clean Energy acquires, develops and operates clean and renewable energy projects. ALLETE Clean Energy owns and operates, in four states, about 661 megawatts of nameplate capacity wind energy generation that is contracted under power sale agreements of various durations.

ALLETE Clean Energy also engages in the development of wind energy facilities to operate under long-term power sale agreements or for sale to others upon completion, with nearly 400 megawatts of projects scheduled to come online in the next year. ALLETE Inc. is an energy company headquartered in Duluth, Minnesota. In addition to its electric utilities, Minnesota Power and Superior Water, Light and Power of Wisconsin, ALLETE owns ALLETE Clean Energy, based in Duluth; BNI Energy in Bismarck, North Dakota; and has an 8 percent equity interest in the American Transmission Co. More information about ALLETE is available at ALE-CORP 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 Commission.