Introducing a solar-combi system for hot water production and swimming pools heating in the Pancretan Stadium, Crete, Greece

National stadiums constitute large energy consuming infrastructures, exhibiting extended energy needs for lighting, indoor spaces heating, hot water production, swimming pools heating etc. In this article a solar collectors - biomass heater system is studied to meet the fmal thermal energy needs for hot water and swimming pools heating for the Pancretan Stadium, Crete, Greece. Currently the above needs are covered with the consumption of 16,500 lt of diesel oil and 190 MWh of electricity annually. The introduced solar-combi system features as obvious option, given the abundant available solar radiation and biomass, mainly from the by-products of the olive-oil trees cultivation. The proposed system's operation was simulated with annual time series of average hourly values. Alternative dimensioning scenarios were executed, aiming at the total elimination of the diesel oil and the electricity for the particular uses. The economic feasibility of the introduced system is documented versus the avoiding energy resources procurement cost of the existing operation. With the concluded dimensioning, the solar collectors annual penetration is 59.5% versus the annual final thermal energy consumption. The remaining thermal energy needs are covered from 31 to of biomass pellets. The payback period of the proposed system is estimated at 5 years. (C) 2019 The Authors. Published by Elsevier Ltd.