They work basically unimpaired into zone 4b, which includes all of northern Michigan. This encompasses something like 98% of the entire human population of North America and even the vast majority of Canada.
They will need some support on the coldest days in up to zone 2b, at which point their efficiency drops to a mere 100%.
You’re spreading fossil fuel industry-driven FUD. Stop it.
They work basically unimpaired into zone 4b, which includes all of northern Michigan. This encompasses something like 98% of the entire human population of North America and even the vast majority of Canada.
They will need some support on the coldest days in up to zone 2b, at which point their efficiency drops to a mere 100%.
You’re spreading fossil fuel industry-driven FUD. Stop it.