Four Ways to Beat Pool Energy Costs
Randy Mendioroz, principal of Aquatic Design Group (ADG), says that annual operating costs for an outdoor pool can cost thousands with natural gas (71 percent of total cost), electricity (14 percent), pool chemicals (10 percent), and water (5 percent).
ADG offers four ways to "green up" pool operations:
Thermal blankets. While some pool owners may grumble about removing and replacing covers each day, a well-insulated set of thermal blankets on a pool (even indoors) saves more costs than just about anything else. Studies on outdoor pools have shown natural gas cost savings of up to 40 percent for operators who dutifully replace pool blankets every evening. At an average capital cost of $2.50 per square foot of water surface area, thermal blankets can pay for themselves in six to 12 months.
Sun power. When natural gas had a unit price of $0.55 per thermal unit (therm), proposing solar was an exercise in political correctness since the payback averaged eight to 10 years and the average life of most systems was 12 years. Today, however, with natural gas prices hovering in the vicinity of $0.85-$1.00 per therm, more pool operators are going solar.
Installation cost for passive solar systems (assuming suitable mounting space with proper solar orientation) runs approximately $18-$22 per square foot of solar panel. The amount of solar panel required varies by region, but an average of 80 percent of water surface area is common. With a potential annual operating cost savings of $65,000-$75,000 (e.g. for 50-meter pool) and an expected full return on investment within four to six years, solar heating may be attractive to the average pool operator.
LEDs. Replacing energy-consuming incandescent underwater lights with high-efficiency LED fixtures can dramatically reduce expenses. A 70-watt LED fixture produces approximately the same amount of light as a 450-watt incandescent fixture, but saves nearly 85 percent in the amount of energy consumed. Initial capital costs for LEDs are approximately double that of incandescent: $500 per LED fixture, as opposed to $250 for an incandescent. However, LED lights will provide 55,000 hours of light compared to 3,800 hours of incandescent light.
Salt water chlorine generation. Chlorine may be the most popular pool sanitizer, but when managed improperly may cause high levels of chloramines -- the true culprit behind the obtrusive "chlorine" odor. By combining an adequate chemical control system equipped with total water balance control and a part-per-million residual analyzer and properly sized chlorine feed systems, such problems can be eliminated.
A healthy, virtually chemical-free alternative is an on-site salt water chlorine generation system. Non-iodized table salt (sodium chloride) is added directly into a swimming pool. Salt dosing levels typically range from 3,000 parts per million (ppm) to 5,000 ppm. Human tears have a salinity of 7,200 ppm (sea water: salinity of 36,000 ppm), so the concentration in the pool is relatively low: no salty smell, taste or feel.
As saline water passes through a chlorine generating cell, low electrical currents transform salt into chlorine. Once the chlorine has killed bacteria and other organic compounds, it reverts back to salt, and the process begins again.
Despite relatively high capital and maintenance costs, the advantages of salt water chlorine generation include reducing or eliminating the storage and handling of chlorine and other chemicals, eliminating the cost of purchasing liquid chlorine, and producing water with a more natural, smooth and silky "soft water" feel, akin to a European spa treatment.