Energy and environmental benefits of an integrated solar photovoltaic and thermal hybrid, seasonal storage and heat pump system for social housing

A facility based on a photovoltaic and thermal hybrid solar field with a seasonal storage tank coupled to a water to-water heat pump is presented in this paper as an adequate energy supply system for a building of social homes in Zaragoza (Spain), currently under construction. Two types of complementary software have been used for the complete design, sizing, and simulation of the system. Design Builder was used to determine the hourly demands from the construction drawings, and TRNSYS was then implemented to dynamically simulate the whole energy system. System performance has been tested in terms of 3E aspects (energy, environmental and economic) with a few well-known key performance indicators. Results obtained by the combined use of the demand simulation software and quantification with different indicators (KPI) show that the proposed solution is suitable for this building: the calculated coverage of the domestic hot water demand is about 80%, the payback period is 8.5 years, and the installation could avoid 44,200 kgCO(2)/year of global warming potential. To sum up, this paper shows how this novel, high-efficiency heating system is a good solution for social housing, owing to its low energy costs and a possible subsidization of a fraction of the high initial investment.