This article is not about what size of pump to choose, it is about comparing costs between pumps of the same size, in terms of their up-front cost and running costs. To read about what size pump to choose, see the article on Filtration and Pumps.

The cost of running a pump is dependant on how may watts it uses as electricity is measured in terms of kilowatt hours, or the quantity of watts, in thousands, used in an hour. The larger the pump the greater the watts it uses, however pumps of the same pumping power can differ considerably in their watt usage. An energy efficient pump that delivers 4200 gallons per hour may run at 550 watts while another that delivers the same volume of water may run at 850 watts.

Does that mean that over time the 550 watt pump will save money? Not necessarily. Pumps are only warrented for one or two or three years, generally. If you live in an area where electricity is cheap and the pumps you are considering are warranted for a year or two, then the added cost of the energy efficient pump, and its replacement, may be greater than the energy costs it will save over the same time period.

If, on the other hand, you live where the cost of electricity is high and you are looking at a pump with a three year warrenty that uses significantly less electricity than the other, then the energy efficient pump may more than pay for its extra up-front cost over the long term.

How to know? A Life Cycle Cost Analysis. Find the cost of electricity in your area, figure how long the pump should last, (generally at least two times the warranty), the number of watts it runs on and do the math. Here