I'd like to use compact fluorescent bulbs on a photo cell circuit to save energy, but the manufacturer doesn't recommend it. Is it just because they won't last as long, or are there other concerns. If it is only a longevity issue, how much is the life shortened? Nobody I've comtacted seemsc to be able to answer this. Please Help a dumb eye Doctor!

Please clarify - which manufacturer recommends against it? The photo cell manufacturer, or the CFL manufacturer? If you can provide a link that might help as well.

BTW - here's a link to a CFL with built-in photocell - perhaps that would solve your problem? Satco S7347 23W Photocell =100W CFL

It's because a photocell acts as a dimmer.

You can try using dimmable CFLs with the photocell and see if they work.

Old wives tales I think. I have 12 lights worked off a photo cell switch (dusk to dawn operation). I used to use 25 watt incandescent bulbs that blew out about 3 times per year. As an experiment I invested in CFLs and have had them in the same fixtures with the same photocells and have not had to replace a single one in over a year. The savings in maintenance time alone is worth it, but in addition the new bulbs are 5 watt versus 25 watt and cost about $2.10 each (ordered on the internet) versus $1.00. All in all a good investment and worthwhile ignoring the foolish instructions to not use CFLs with photocells!