solar powered fans?

[eric]

I've had a fan hooked to a themocouple to turn it on when I reached a set point.

What do you think of just wiring a DC fan to a tiny solar panel or two and have the lights activate it? Couple put in a pot and tweak it to keep the range in line.

Do some canopies already do this?

[GaryP]

Eric,

I don't think you are going to get enough CFM from a solar powered fan. I'm running 100 CFM fans on my 125 with MH. The fans don't really pull that much amperage. I don't know if that's the place to look for electric savings. Lights and pumps are a better place to look for increased efficiencies.

[Shark_Bait]

I think you would need more than 2 panels. Each panel is usally about 2 volts if you get one with the correct amps output. So might need 6 panels or so for each fan... would wind up covering the whole top of the tank to get enough power to push the fans.
just my $0.02

[eric]

I suppose you're correct. One less plug was actually my reason for dreaming it up. And laziness - my cord is just a foot too short and didn't want to extend it.

[GaryP]

Consider power strips.

[NaCl_H2O]

Now, solar powered lighting would be useful ;) ;)

I think that's called a hole in the roof :o

[GaryP]

I saw something about how the Japanese use fiber optics to distribute sunlight throughout an office building and light it. That would be cool.

[bprewit]

I used a sun tube with a filter intended for stage lighting to light my tank at one time. I worked!