GreenTech Media recently showed that the main energy statistics agency for the United States, the Energy Information Agency (EIA) was missing information on a whopping 45 percent of installed solar PV. The problem is with their methodology – they don’t count customer-sited solar, like systems on rooftops. GreenTech found that actual solar production was 50 percent higher than official estimates. Three states (CA, AZ, HI) now get more than 5 percent of their electricity from solar, something you wouldn’t know if you only consulted EIA.
EIA data says that Minnesota produced no electricity from solar in 2012, and 2.7 gigawatt hours in 2013. Here is the chart from their Electricity Browser:
In reality, Minnesota produced something like 18.7 gigawatt hours from solar PV in 2013, or 592 percent more than EIA estimates.
I didn’t just use wikipedia data to make this estimate, I used data from the Minnesota Department of Commerce’s Annual Distributed Generation Interconnection Report, which utilities are required to submit each year showing existing and new DG facilities. The number above comes from only six utilities in Minnesota, which I think are some of the largest in terms of number of customers.
Here is the breakdown of installed capacity at the six utilities:
I couldn’t find a report on total installed PV capacity or production on Commerce’s website, but it could be hidden in dockets somewhere.
If you’re looking for accurate data on the growth of distributed generation, like solar, you can’t (yet) count on EIA. GreenTech outlines a bunch of reasons why this is important, including making the EPA’s Clean Power Plan to regulate existing power plants look harder to accomplish than it might be.
In Minnesota, solar is a small (0.04% of total generation in 2014), but growing part of the energy mix. Accurately tracking this growth is important for making good policy, especially in regards to distributed (customer-owned) generation, which is usually outside the control of utility planning processes.