Duluth-based Minnesota Power yesterday received approval from the Minnesota Public Utilities Commission (PUC) to proceed with a joint-venture to build a $700 million natural gas-fired power plant in neighboring Superior, Wis.

Critics contend this is a step backwards, and they can only say this if they have not thoroughly studied the reasons behind this move.

Minnesota Power, like other utilities across the country, sees the value in converting more electrical production to non-fossil future sources. It wants to tap wind, solar and hydro-power generating opportunities more. But it can’t because its existing power generation comes solely from coal-fired power plants.

When power generation suddenly drops from wind or solar, a utility needs to be able to quickly switch over to another source of power generation. Coal-fired plants take a while to go from zero to significant megawatt generation. Gas fired plants, however, can go from zero to significant quickly. Think of it as the difference between a coal-fired stove in you kitchen versus a natural gas stove.

Minnesota Power has plans to develop additional wind and solar power generating stations in northern Minnesota. Also, it has a major contract to receive hydroelectric power from Canada. It cannot do more on these fronts until it has this gas-fired plant online.

For anyone who wants to truly understand how utilities are transitioning from fossil fuel-fired electricity generation to renewable sources, take a closer look at Minnesota Power (owned by Allete, Inc., also of Duluth). And on a larger scale, there’s Minneapolis-based Xcel Energy, which ranks as one of the nation’s leaders on this issue.