Low Temperature Solar Thermal Domestic Hot Water Potential on Croatian Islands
Abstract
This paper discusses solar thermal energy as a cost-effective alternative to conventional energy sources for the supply of domestic hot water for private housing and tourist accommodation along the Croatian Adriatic coast. The initial analysis concerns domestic hot water system designs and simulation. This includes a brief view on the following topics: simulation software, hourly climate data and simulation procedures. Daily, weekly and annual domestic hot water demand profiles reflect fluctuations in utilization of tourist accommodations. Potential solar yields along the coast significantly increase southwards. Simulation results for annual specific solar yield and solar coverage ratio are summarized for four different solar thermal systems, each with two collector orientations and using climate datasets from Rijeka, Zadar and Hvar. The number of inhabitants and tourist overnight stays are used to estimate current final energy consumption and potentially replaceable amounts, showing that only 10% of ST installations for the proposed applications would nearly double the current share of renewable energy in Croatia. Consequently, economic methods are used to show that investment payback times are significantly shorter than the expected system lifetime.