It’s one of those ideas that just makes sense. When it’s hot and you need a fan to cool off, the sun is usually shining. So why not power that fan using energy from the sun? Solar-powered window fans are popping up all over these days, and we’ve even seen a solar-powered air conditioning system available on the Toyota Prius. There are also solar-powered attic fans (which have larger panels and work more efficiently than either window fans or car fans). Solar attic fans often benefit from more direct sunlight throughout the course of the day, and they have access to the hottest part of a house, i.e. the attic.
The fan shown above is about half an average window’s width in size, and can be used to circulate air inside your house, apartment, dorm room, kitchen, bedroom, living room, garage, or anywhere else — even inside a car or RV. Just remember to close your window and lock your doors when you’re done (to discourage theft).
Unfortunately, many of the reviews I’ve read on these smaller window units complain of weak and inconsistent performance. They work best when exposed to direct sunlight, but unless your house rotates, it is naturally shaded for at least half of daylight hours. As photovoltaic panels become more efficient and offer higher output potential per cost, this solar-friendly device will no doubt improve. Until then, it’s still a good idea, even if it is a lacking a bit in power.