Advances in pool heating technology have made the cost of solar pool heaters competitive with the more traditional gas-fired and electric heat pump systems. Solar swimming pool heaters have very low operating cost since they do not use a purchased energy source to supply heat to the pool water, but instead gather the free radiant heat energy of the sun. The minimal cost to operate a solar heater are attributable only to the electricity used to power the circulating pump.
Solar heating systems consist of a solar collector, a filter, a pump and a flow control valve. The solar collector is actually a heat exchanger that transfers the sun's energy to the pool's water as it circulates through it. They are generally shaped like large panels, although some newer designs vary from this traditional shaped piece of equipment. A filter is installed between the pump and the solar panels to remove any impediments in the water so that the tubing inside of the panels does not become clogged. The pump simply circulates the water through the filter, the solar panels and then returns the warmed water to the pool. Some smaller solar heating systems can sometimes use the existing pool pump if it has sufficient size, but most larger systems require a separate pumping device due to the increased pressure drop across the solar panels and plumbing. The flow control valve, also known as a three way valve, can either be an automatic or manual device to divert the pool water to the solar panels to help regulate the temperature.
Solar heating systems have a slow response time and may need to be run for an extended period of time before the pool water is sufficiently heated, as opposed to gas pool heaters. They are also best suited to applications that do not require unusually high pool water temperatures, but are ideally suited for maintaining water temperatures of 80 to 85°. Although most pool owners that employ the use of solar heating panels use them as the sole source of heat, they are also very well-suited to operate in conjunction with another heating source such as a gas-fired heater or a heat pump.
A typical solar pool heating system will generally have an installed cost of $2-$4000. And although this initial cost is higher than the more conventional systems, solar heating systems typically pay for themselves in a couple of years by eliminating the cost of an external energy source (such as gas or electricity) for heat.
Solar heating systems are dependent on your localized conditions, most notably the local climate and the availability and quality of the solar energy. They need to be cited to have line of sight access to the sun and if this is not possible at a location beside the above ground pool where they are typically installed, they can be located remotely by a longer run of plumbing. In fact, they are often installed on the roofs of nearby structures, for both technical and aesthetic reasons. The amount of solar radiation that is available will depend upon the season, the time of day, the geographic location, the local weather and any nearby buildings or landscape that may obstruct the direct rays of the sun.
The size of the solar heating system will need to be determined by an experienced contractor. Generally speaking, this results in a solar collector that is anywhere between 50% and 100% of the surface area of your swimming pool. The sizing of these panels will also vary depending on the pools swimming season and the localized climatic conditions.