Although a layer of snow can cause a solar-cell blackout for a period, not many regions experience heavy snow for more than a few months, they said, and even in midwinter panels don't usually stay snow-covered for long.
"Sometimes snow actually helps solar cells," Michigan Technical University researcher Joshua Pearce said, referring to the albedo effect, when sunlight reflects off snow.
It can make a panel generate more electricity in the same way that it gives skiers sunburn on sunny winter days, he said.
Pearce worked with researchers from St. Lawrence College and Queen's University, in Kingston, Ontario, and industry partners to study the effect of snow on the Open Solar Outdoors Test Field, a fully grid-connected test system that monitors the output of more than 100 photovoltaic modules and correlates their performance to meteorological readings.
They created a computer model to predict how much electricity production would decline with various amounts of snow cover on solar modules mounted at different angles from flat to steeply pitched, a Michigan Tech release said.
"In most cases power losses are minimal, even in snowy Canada," Pearce said, noting the model matched data from a number of Ontario's commercial solar farms.