Solar water heater sizing and economic evaluation for local hospital

Increasing Renewable Energy (RE) share is one of the most effective strategies for enhancing sustainability. Among many commercially mature technologies, Solar Water Heating (SWH) systems are very attractive. Despite that, the percentage of utilizing SWH systems in the Palestinian Territories (PT) had decreased significantly in the last two decades. High rise buildings and the resulted limited roof area, and lack of required fund turned this option to become a nonpriority. The Palestinian Authority (PA) adopted many incentives and launched funding programs to convince local community in investing in RE, including SWH. This research considers a 100 beds capacity local hospital water heating system as a case study. Currently, the hospital uses diesel boiler, fuel costs $37,753 per year and required output boiler temperature equals to 60°C. In order to support the boiler and reduce hospital full dependency on diesel fuel, this research considered installing a SWH system on the roof available 250m
²
area. Both of the Flat Plat (FP) and Evacuated Tube (ET) systems are considered as alternatives. The f-chart method is used for investigating the alternatives technical performance through calculating the annual solar fraction. Results revealed that for the FP SWH system, annual solar fraction (F), Simple Payback Period (SPP), Present Worth (PW), Internal Rate of Return (IRR), and Saving to Investment Ratio (SIR) are 51.4%, 5.52 years, $27,677, 17%, and 1.29, respectively. For the ET SWH alternative, these values become 57.9%, 5.2 years, $37,730, 19%, and 1.38, respectively. Based on that, ET system is recommended.