Wind turbines are one of the resources that would be used to help the state realize Gov. Tim Walz’s vision of 100 percent carbon-free energy. The author suggests that wind and solar intermittence means we’d still have to rely on other sources like coal, nuclear and natural gas, which has cost implications as well. (The Minnesota Star Tribune)

This month, the Star Tribune Editorial Board endorsed Gov. Tim Walz's vision of a 100 percent carbon-free electric grid ("Time to move ahead with clean energy," March 7), largely due to their belief that concerns about the intermittency of wind are overblown and that wind is now the most affordable source of electricity in Minnesota. Both of these perceptions are incorrect.

The fact that the wind does not blow 24/7 is not an oversimplification or a disservice to the debate. It is the debate, because the intermittency of wind and solar has profound implications for reliability and cost.

For example, each of Minnesota's three investor-owned utilities told the Minnesota Public Utilities Commission that production from their wind turbines plummeted during the polar vortex on Jan. 29. Wind turbines in North Dakota either were shut down because it was too cold to safely operate them, or their output was greatly diminished because of low wind speeds.

As a result, wind provided just 4 percent of electricity output during the polar vortex, while operating at only 24 percent of capacity. In contrast, 45 percent of the electricity generated in the regional power grid, the Midcontinent Independent Systems Operator (MISO), during the cold snap came from coal, 13 percent came from nuclear and 26 percent from natural gas.

The fact that the wind cannot be relied upon to generate electricity when we need it most means we must still pay to keep our coal, nuclear and natural gas plants online, in addition to paying for wind and solar power. In the end, Minnesotans must pay twice for electricity they use once.

The Editorial Board cited Steve Morse, who claimed it is cheaper to put in new wind than to operate old coal, but this is demonstrably false.

Form 1 data submitted to the Federal Energy Regulatory Commission (FERC) by Minnesota utilities show the cost of generating electricity at two of Minnesota's largest coal plants, Sherburne County and Clay Boswell, was $30.58 per megawatt hour (MWh) and $32.34 per MWh, respectively, in 2017, the most recent year for which data were available.

In contrast, Bloomberg New Energy Finance estimates the unsubsidized cost of generating electricity from new wind is $38 per megawatt hour, meaning it is 24 percent more expensive than electricity from Sherburne County.

Furthermore, Bloomberg's estimates do not take into account the large costs associated with maintaining the reliable power plants needed to generate electricity when the wind isn't blowing or the sun is not shining, and it also does not include the costs incurred through additional property taxes, building transmission lines or utility profits.

Speaking of utility profits, Xcel Energy's interest in building a carbon-free electricity grid may lie more in its mission to enhance corporate profits than in saving the environment. Most people do not realize electric utilities are not truly private companies; they are government-sanctioned monopolies that are guaranteed a 7.5 percent profit on every single dollar they spend on infrastructure.

This gives them a powerful incentive to build as many wind turbines and solar panels as possible, not because they generate cheaper electricity than other sources of energy, but because it increases their guaranteed profits, regardless of whether the sun is shining or the wind is blowing.

Gov. Walz's proposal is a government-mandated wealth transfer from Minnesota families to the monopoly utilities that helped write the legislation. This is crony capitalism at its worst.

A MISO analysis concluded that the complexity of integrating intermittent renewables increases sharply (exponentially) as their market penetration increases from 30 to 40 percent of total electricity generation. Wind and solar produced approximately 19 and 1 percent of Minnesota's electricity in 2017, respectively.

This means we have not yet even begun to experience the most difficult challenges associated with making sure that we are producing enough electricity while increasing our reliance on intermittent renewable sources that are incapable of generating electricity 24/7.

Isaac Orr is a policy fellow specializing in energy and environmental policy at Center of the American Experiment. Follow him on Twitter @thefrackingguy.