Kelln Solar has installed many community solar pool heating systems in Saskatchewan.
The first, in Bengough in 2005, saved the town over 60% of their previous heating bill and probably saved the pool from being closed down because of the rising operating costs. For many small communities the swimming pool can be a very important amenity in maintaining the vibrancy of the town and augmenting the pool heating with solar can help to reduce the annual expense.
Efficiency of Seasonal Pool Heating with plastic panels
Solar pool heating operates best seasonally because the days are long in the summer and the ambient air is reasonably warm. It is possible to effect a major solar contribution using highly-efficient and economical plastic (polymer) panels. The plastic panels means that pool water can be used directly eliminating energy losses from heat exchangers otherwise required.
Pool Heating of any Size
Any pool can benefit from solar pool heating. For pools which are typically not heated such as smaller above-ground pools, which depend on good weather alone, solar heating can make the water so much more comfortable many more days of the years. Systems can be designed by anything paddling pool size and up. There needs to be a circulation pump but for pools with their existing pump, it is often sufficient to do the job. For community size pools, a booster pump is typically used to ensure proper circulation through all panels.
Roofs or Racking - space is required
For small systems panels can be put on the ground, drained and rolled-up as season's end. For larger system, where possible the panels are located on the roofs of adjacent building assuming a good solar orientation and enough room between venting and architectural features. In some cases dedicated overhead racking is built to accommodate the panels. Typically a minimum of fifty (50%) percent of the pool's surface area is matched with solar panel area - more if wind and higher operating temperatures are factors.
Target of at least 50% heating
In general the target is to offset about 50% of the annual heating requirement for the pool. More heating can be offset by installing a larger solar system but past 75% of the pool area, it is a case of diminishing returns. There are always cloudy times in which the conventional pool heating system is required to keep the pool temperature up because anyone knows pools knows that the first sunny day after a cool spell. everyone wants in the pool and they expect it to be warm.
Solar Heating all Season long
Not only is the solar pool heating system effective at keeping up the heat throughout the summer, it can be used exclusively, or at least primarily, to heat the water at the start of the season. If may mean filling the pool a bit earlier than usual but the solar system is very effficient when the water is cold and municipal water is definitely cold. Even if some use of the boiler is required at the end, it is best to save the use of the boiler after the solar has done the first warming. The greatest heat loss from indoor pools is from evaporation and again replacement water is cold so it is best if the replacement water is circulated directly through the solar system
Money and CO2 saved over many years
Solar pool heating is the most cost effective of renewable energy technologies. Depending on the challenge and cost of mounting the solar panels, a solar heating system can pay for itself in savings in a matter of years and the solar panels are expected to last at least twenty years. So there are many years of saving money and reducing greenhouse gas emissions.