Evaluation of Different Sustainable Solutions to Enable an Increased Utilization of Outdoor Swimming Pools

Over the last decades the construction of swimming pools for recreation activities has grown exponentially, especially in the countries of southern Europe where tourism is one of the main economic activities. In Portugal, swimming pools are located in hotels and resorts but mostly in villas, where they reach hundreds, or even thousands. They can be considered a leisure equipment, but require considerable amounts of energy to operate. The energy requirements of such pools are especially relevant when, to keep the water temperature comfortable beyond summer months, heating systems are used during long periods of the year. At this level, conventional systems used to heat the water commonly make use of non-renewables forms of energy, which besides imposing high energy costs, cause a negative environmental impact. In this scope, the approach here presented describes the implementation of a sustainable swimming pool. In order to improve the energy of such pools two goals should be considered. The first goal is to suppress non-environment friendly systems and, then, find out how to integrate different solar energy collecting systems, either to heat the water directly or to allow thermal storage for later usage. At this level Phase Change Materials can be used. In order to fully implement it, some relevant issues need to be solved beforehand, as for instance the individual and integrated systems’ efficiency, the control methods to operate them and, of course, the investment costs. One second goal is to reduce energy losses, through a pool cover that besides energy saving, allows safety and easy operation. This paper evaluates and compares different solutions that allow heating the water of swimming pools using renewable energy sources, to increase their utilization throughout the year.