Two Michigan state senators ignored the downsides of solar technology in their recent argument for more green energy incentives.

Solar energy is the next step for Michigan’s energy policy, Sens. Jeff Irwin, D-Ann Arbor, and Ed McBroom, R-Waucedah Township, argued last week in an op-ed for The Detroit News. McBroom and Irwin were making the case for Senate bills 152 and 153, which would create additional solar power incentives for companies and individuals. But they left out important drawbacks about this type of green energy.

Read them for yourself: Michigan Senate Bills 152 and 153

The op-ed opens by claiming that solar is the cheapest it has ever been. While this is true, the senators neglect to explain why. Renewable energy is only cheap because it is highly subsidized.

Energy policies at both the federal and state level heavily favor wind and solar over fossil fuel and nuclear plants.

The growth of solar has been powered by subsidies on the one hand and regulatory pressure on the other. Even so, adoption has been slow.

According to the Energy Information Administration, solar energy facilities produced electricity just under 20% of the time throughout the year, and less than 7% of the time in the month of December.

The highest tally came in under 30% during the months of June and July. By comparison, nuclear’s production never went below 70% throughout the year, while coal had an average of above 50%.

“Solar’s intermittent and unreliable performance means that backing power sources, like natural gas and nuclear, are still required to be built to ensure customers have reliable energy,” said Jason Hayes, the Mackinac Center’s director of energy and environmental policy. “Therefore, utility customers are required to pay for the construction of both forms of energy.”

Editor’s note: Ewan Hayes, an intern at the Mackinac Center, is the son of Jason Hayes.