When asking Chicago residents why they have not invested in solar for their homes or businesses, what is a common response? “Have you seen how much snow we get 6 months out of the year?” The idea that snow detracts from solar energy production is a common one. With the right solar installation techniques, though, it is not a valid reason to halt solar investment in chillier states.
Bill Marion, principal scientist in the PV performance and reliability lab and the National Renewable Energy Laboratory (NREL) in Golden, CO, studied the effects of snow on PV system performance. Looking at Boulder, CO and Middleton, WI, he did find that PV output can reach zero when snow is piled on a flat roof.
What is the solution? If the roof is not tilted, Marion suggests that a ground-mount system is ideal. Preferably, one with a good tilt angle and a significant gap between the bottom of the module and the ground to give snow a generous deposition depth as it slides off the glass. Marion plans to follow snow’s impact on PV output this winter as well, in order to create guidelines on how to mount modules to maximize the amount of snow fall-off.
With the issue of snow covered, what about the belief that Chicago is too cold and cloudy for efficient solar energy? In reality Midwest states do experience a good amount of sun.
“Michigan has an average of 4.2 hours of peak sunlight per day each year, according to Mark Hagerty, President and Founder of Michigan Solar Solutions. ‘Florida, the Sunshine State only has a little over five hours. Interestingly, Germany leads the world in the percentage of electricity generated by solar, but has less than four hours of peak sunlight a day,’ says Hagerty.”
Additionally, solar panels are actually more efficient in cooler temperatures than in hot ones (Read more here).
So what is your excuse for not investing in solar energy? If you want to see local solar in action, join the Illinois Solar Energy Association’s 2011 Solar Tour! The Tour is a free public event to demonstrate how home and business owners are utilizing solar, wind, geothermal, passive solar design, and energy efficiency to reduce their dependence on fossil fuels and be energy independent. Stay updates on the 2011 Solar Tour and other ISEA events through our Facebook and Twitter pages.