It is a dark, windless 6:30 a.m. when I open my copy of the Star Tribune to read that a large solar farm has won approval. I am warm and cozy in my apartment, heated by an electric heating system.
It will be a few hours before the sun is high enough to stir electrons from those solar panels and even longer before there is enough wind to turn big wind turbine blades.
Fortunately, downriver at Prairie Island, there is a nuclear plant that produces a constant supply of energy per year, night and day, rain or shine, wind or calm.
This will be a big help at night to those 25,000 homes that the new solar farm is supposed to supply. Solar panel systems worldwide have capacity factors of about 15 percent, which is the percent of round-the-clock capacity they actually produce.
The capacity factor of nuclear plants like ours at Prairie Island is more than 90 percent, and their downtime is mainly for fuel replacement and maintenance.
There is a place in our economy for carbon-free renewable energy like wind and solar. But to really replace the huge output of fossil-fuel electric power, we will need carbon-free nuclear and low-carbon natural gas.
Rolf Westgard
Guest faculty member on energy subjects for the University’s Adult Education Program
