Enhancing solar water heater system for utmost useful energy gain and reduction in greenhouse gas emissions in Gaza

Palestinians living in the Gaza Strip are in a very delicate situation when it comes to achieving sustainable growth in the energy sector, due to financial, environmental, and political challenges. Replacing electric water heaters with solar water heaters (SWH) in Gaza can lead to better hot water supply, cost savings, and gas emission reduction. Therefore, this study aims to improve the solar hot water system by determining the best values of tilt angle and incidence angle at which the useful energy obtained from a solar thermal collector has its optimum value. In addition, to evaluate the overall benefit of SWH in terms of cost savings from SWH replacement and reduction in greenhouse gas emissions which will provide useful information to investors and decision makers. Two software programs are used in the current study: The first software program is Transient System Simulation Tool which is used to calculate the useful solar energy obtained from the flat-plate collector and the second software is Design-Expert with response surface methodology which is utilized to obtain the optimal tilt angle. The simulation results show that the value of the useful energy gain of a solar thermal collector depends on the values of the tilt and incidence angles. The optimal value of the tilt angle is not fixed all over the year instead it has different values that are subject to the season or months of the year. The optimum value of incident angle is small and varies from 10 to 12 degrees. The optimized tilt angles for Winter, Spring, Summer, and Autumn are 39.57 degrees, 26.72 degrees, 20.15 degrees, and 32.2 degrees and the maximum useful energy obtained with these angles are 225.69 kWh, 481.56 kWh, 599.40 kWh, and 386.19 kWh, respectively. The result exposes that the utilization of a standard solar water system can save up to $857.87 in energy cost per year. It was found that the payback period of the investment for a solar water heating system in Gaza is around 3.4 years. The results are promising and can motivate investors and decision makers to use SWH and solar energy.

Automated summary

This study aims to improve the solar hot water system in Gaza by determining the optimal tilt angle and incidence angle. Simulation results show that the useful energy gain of a solar thermal collector depends on the values of the tilt and incidence angles. The optimized angles can lead to higher energy efficiency and cost savings.