Heating an outdoor pool in the summer months can account for as much as 60% of a home’s summer energy bills, making it more expensive to heat a pool in the summer than the house in the winter, according to BC Hydro. Each degree you set your pool’s temperature above 25.5 degrees C will cost 10-30% more in energy bills. This can add up for many recreational pool users who prefer their temperatures a bit warmer than average.
Solar pool heating will instantly reduce those heating costs, as well as extend a pool’s season by several weeks and help reduce carbon emissions. Solar energy heating for outdoor pools generally uses unglazed collectors on a seasonal basis. These collectors will raise your pool’s temperature using the heat from the sun anywhere between 60%-100% throughout the season, and often eliminating the need to start the conventional pool heater on clear sunny days. This efficiency allows for a payback period of two to five years. For indoor pools, glazed collectors identical to those found in solar domestic hot water systems are more appropriate.
How it works is simple: the unglazed collectors are thin and flat and usually mounted on the roof, facing the sun. The pool water that normally passes through the pool filter is simply diverted to pass through the collectors before it returns to the pool. The collectors, being black, absorb the energy of the sun and transfer it to the pool water that is passing through them – heating the water.
The existing pool filter pump is all that is necessary, 99 % of the time, to circulate the water through the solar collectors and return it to the pool. A valve – either manual or electronic – is used to divert the water to or away from the solar collectors. When the solar system is off the water returns directly to the pool. When the system is on, the water travels into the solar collectors before returning to the pool (warmer!).