Minnesota's Largest Coal Plant Becomes 710MW Solar Hub

The giant smokestacks at Minnesota's Sherco power plant once symbolized old-school energy. Today, they're watching their own retirement party as the state's largest coal facility transforms into one of America's biggest solar success stories.

Xcel Energy just completed the first three phases of its massive solar array at the former coal site. The 710-megawatt installation now generates enough clean electricity to power 190,000 homes, with plans to expand to 910 megawatts by 2029.

The numbers tell a remarkable story. Sherco opened in the 1970s as a coal powerhouse, eventually growing to 2.2 gigawatts across three units. At its peak, the plant consumed a staggering 9 million tons of coal every year.

But economics drove the change faster than politics ever could. When Unit 3 suffered a catastrophic failure in 2011, repairs cost $200 million on top of the unit's original billion-dollar price tag. Just two years after fixing it, Xcel announced plans to retire all three coal units.

The company initially considered replacing coal with natural gas. State regulators balked at the high costs, and renewable energy advocates pushed for a better solution. Solar power won on merit, not mandates.

Two of Sherco's three coal units have already shut down. The final unit will close in 2030, marking the complete transformation from coal to clean energy at Minnesota's former fossil fuel flagship.

The Ripple Effect

The Sherco transformation extends far beyond solar panels. Two massive lithium-ion battery systems totaling 600 megawatts are in pre-construction approval, ready to store solar energy for use after sunset.

The site also features an experimental 10-megawatt iron-air battery system. This longer-duration storage technology could revolutionize how we save renewable energy for cloudy days and calm nights.

A new transmission line called the Minnesota Energy Connection will deliver up to 4,000 megawatts of capacity, with renewables dominating the flow. The line includes space for a 420-megawatt gas backup plant for rare moments when wind and solar fall short.

Across America, renewable energy now accounts for over 30% of generating capacity. During the first five months of this year, utility-scale solar power jumped 21.6% compared to last year. Wind and solar combined now outpace both coal and nuclear power nationwide.

The transformation happening at Sherco proves that clean energy isn't waiting for perfect conditions or government mandates. When solar and storage become more economical than repairing old coal plants, the market makes its choice.

What once seemed impossible—replacing America's coal infrastructure with renewable energy—is happening faster than almost anyone predicted, one retired smokestack at a time.