The Challenge

The challenge to De Viris opened the doors to the establishment of a full study in order to find the optimal solution that replace the thermal energy needs of a typical “Monte” located in Terena, Alentejo. Specifically, we dealt with production of Sanitary Hot Water (AQS) environment and climate (heating and cooling), with the ultimate aim of optimising the energy bill, and using as much of renewable sources of energy, thus promoting energy efficiency solution.


The Solution

The study began with an assessment of available resources and energy needs of the “Monte”.  Based on the assessments were developed six different scenarios that are differentiated by both the mode of production of heat and cold (biomass boiler, heat pumps and chillers) as the mode of distribution (fan-cools and radiant floor). The scenarios were then compared on a technical and economic analysis (of the costs of operation and investment) and faced with conventional systems. The optimal solution developed provides for the implementation of a solar thermal system for the production of AQS and support to heating the pool, as well as a heat pump (type of air-water) to supply the needs of climate and support the production of AQS.  The distribution takes place through fan-cools and towel holders, those in the toilet. This solution also provides for the generation of electricity through a photovoltaic system of 3.5 kW, according to the programme "Renováveis na Hora" (micro generation).

The Advantage

The use of solar thermal system allows not only to reduce consumption of conventional energy, resulting in the corresponding impact on the energy bill, but also making profitable the solar resource in the production of AQS and heating the pool. Although it was not the customer requirement, heating the pool becomes an energy usage that ultimately increase the overall efficiency of the proposed system virtually without additional investment, leading to further enlargement of the normal period of occupation of the pool. The comfort of heating the pool is not alone in this property, the distribution of heating and cooling takes place in a uniform way for homes with the installation of fan-cools providing a very good level of comfort. The proposed solution integrates the complementarily of a conventional system of high energy efficiency (heat pump) with the solar thermal system. When compared with a conventional system (the gas boiler), the proposed system will reduce about 63% of the overall energy consumption.  In turn, the solar photovoltaic system provides an important revenue that allows greatly reduce the pay-back of the installation, estimated at 6 years, and that revenue equivalent to more than 200% of the "conventional" energy bill during the first 5 years.