Federal data confirms Minnesota solar panels don’t work well in winter

Recently-released data from the U.S. Energy Information Administration (EIA) confirms what many of us already knew, that solar panels don’t work well in our Minnesota winters. The data is interesting because this is the first time EIA has shown the productivity (or capacity factor) of solar panels on a monthly basis, as you can see in the graph below.

While solar panels generated nearly 30 percent of their potential output in July of 2018, electricity generation from Minnesota’s solar fleet dropped to 5.6 percent by December.

There are multiple reasons for this. One, the days get a lot shorter in the winter time, thus providing less “fuel” for the panels to generate electricity with. Secondly, snowfall greatly diminishes the productivity of solar panels because the color white reflects light, and according to Ralph Jacobson, the Founder of IPS Solar, it is “too expensive” to clear snow off of the solar panels.

This should be a big red flag, because if it’s “too expensive” to operate your business when it snows, that business probably shouldn’t be operating in Minnesota. This begs the question, why are people building solar panels in Minnesota?

The answer boils down to federal subsidies, and Minnesota government mandates.

In 2013, the legislature passed the Solar Energy Standard, which mandated that 1.5 percent of the state’s electricity must come from solar energy by the end of the year 2020. This is why Minnesota has built solar panels, while other northern states with similar climates do not have nearly as many.


Center of the American Experiment has argued that solar panels have a big cost but only provide a small amount of electricity, and the federal data supports this position. Despite Minnesota’s terrible solar resources, Xcel Energy wants to spend billions of dollars building 4,000 MW of solar not because it’s the most productive way to  generate electricity, but because it will get them the most government-guaranteed corporate profits.