The biggest danger besides wasted money having zero effect is making things worse by sucking the conditioned air of the house into the vented attic. A MUCH better return on investment would be going into the attic, pealing back all the insulation, air sealing the ceiling plane and adding more insulation once finished. Air sealing and blown cellulose is dirt cheap compared to years worth of wasted energy, even in most mild climates.

. Can't recommend any particular text for passive solar design . . . but NOW is definately the time to consider such things; especially in a sunny clime. You can get a lot of benefits from the design for FREE . . . or battle their side-effects forever through heating / cooling / lighting systems. For PV and energy conservation; try Homepower magazine . . . covers the gamut of stuff. I'm in central New York state and PV works here . . it'll surely work where you are. You will likely NOT get incentives like here in NY; we've actually got some pretty good ones right now. HomePower usually includes info on what's going on where in terms of incentives and such; either directly or through links from their site . . . lots of good, real information there . .. Good luck . . Bob Here is a link that might be useful: HomePower magazine

We installed one on our last home and it made a considerable difference. While I agree with the previous poster regarding the need for adequate ventilation, the solar attic fan moves as much as 800 cfm of air actively. I seriously doubt that you would be able to achieve that with a passive ventilation system. The biggest issue, imo, is whether or not you have an attic space to ventilate. We had a partial attic upstairs (over 3 bedrooms). We recommended the solar attic fan to neighbors who had considerable more attic with direct Western exposure. They ended up installing two fans and greatly enjoyed the results from the standpoint of comfort and reduced cooling costs (a/c didn't have to work as hard without a hot attic). We also installed a whole house attic fan (to remove hot air from the house (we did not have/need a/c)). This was optimally used when the outside air temp was 10-15 degrees cooler than the inside. In California we had plenty of cool evening breezes but the inside of the house would take a long time to cool (with out the whole house attic fan).

I was a little skeptical about how happy I would be with the solar cover and reel we bought this spring. We purchased a 12 mil. blue cover and a presto reel. Let me say that it's one of the best things we ever bought. The solar cover works great, and the reel makes putting on and taking off the cover a breeze. It takes only a couple of minutes to put on or take off. We got ours from www.solarcovers.com.