Let's start by putting a common misconception to rest: Minnesota's winter climate isn't a factor in solar energy production.
Solar potential simply is not related to average temperature. Hot or cold makes no difference. It's the sun that's important. And Minnesota's got a lot of it.
Minneapolis has an annual average of 2,509 hours of sunlight, competing in sun potential with the top photovoltaic markets by capacity installed: Italy (first), Germany (second), China (third), France (fifth) and England (seventh).