I have an automated opaque (tan colored) pool cover and find it to save a lot on chemicals (chlorine) and heating. Our pool is solar heated, but we use a propane gas heater to assist and extend the season a month on either side (mid-April to mid-May and mid-October to mid-November). My own experiments showed that without the cover, the pool would lose about 6 degrees at night starting from 88 degree water with night air temperatures in the low to mid 50's (during the part of the season when gas-assist is needed). With the cover on, I measured only a 3 degree loss so it apparently cuts the heat loss in half. I have been told that a solar cover would do better, possibly twice as good so that I'd only lose 1.5 degrees or maybe 2 degrees, but I cannot confirm that (it's hearsay). During the summer when the nights are a bit warmer (in the high-50's to low-60's) we lose about 2 degrees overnight with the cover on and 4 degrees with it off.

We also live in an area where water is relatively expensive at a marginal rate of $4.86 per ccf (hundred cubic feet) or $0.65 per hundred gallons. The cover significantly reduces the amount of fill water that is needed to replace water lost from evaporation. In fact, most of the reduction of heat loss also comes from this reduction in evaporation since evaporation is how most heat is lost (not from direct thermal transfer). Our high water rates and occassional water rationing are why we use a cartridge filter so we never backwash.

My chlorine usage is less than 0.5/day and this is primarily due to the cover, mostly due to blocking the sunlight (UV) during most of the day except for when we are using the pool. Between my wife an I, we have the pool uncovered for use around 12-14 hours per week.

We use an automated cover vs. a solar cover primarily because my wife is handicapped (had polio as a child and often uses a cane for walking) so rolling and unrolling the cover would be too hard for her. Our cover did have some deterioration and cracked along one edge where it folded over possibly from being too loose, but we had that replaced under warranty which was free for the first 3 years (then pro-rated thereafter up to 7 years, so we had it replaced just before the 3 year period was up) though we did have to pay for the labor for replacement ($500? if I recall correctly). We got a slightly (1") smaller cover this time and it doesn't appear to have the "edge fold" problem so we'll see if we can get at least 5-7 years out of this one before replacing it.

Overall, the automated cover is great, but it is expensive (several thousand dollars initially, then about $1500 or so for a new cover every 7 years or so). If you want greater efficiency plus the advantage of having a clear cover help solar heat your pool and you don't mind the manual labor and want to save money, then a solar cover is a better bet. In our case, we didn't have much choice, but we're very happy with our automated cover.

Richard