Hafiz M. Abd-ur-Rehman

Techno-economic evaluation of different types of solar collectors for water heating application in domestic sector of Saudi Arabia

Electric water heaters consumes major part of energy in residential sector and hence there is a need to find an economical solution. One potential solution is to use solar water heating (SWH) systems. The aim of this work is to assess the techno-economic viability of SWH technologies for domestic purpose. In this study, different types of SWH collectors like evacuated tube and glazed collectors are simulated using RETScreen software whose credibility is widely accepted for calculating energy production, life cycle assessment, greenhouse gas emissions, and fuel savings for SWH applications. Calculations are performed to obtain at least 50 % solar fraction on the basis of number of SWH collectors. Other considerations involve collectors types, slope angle, tracking mode, collector thermal loses, collector optical efficiency, and back up fuel which is electricity in our case. Simulations are performed for five different cities of Saudi Arabia. Choices are being made to cover different geographical coordinates of the kingdom that involve Jeddah (western coast), Dhahran (eastern coast), Tabuk (north), Riyadh (center), and Bisha (south). Simulated results based on solar radiations on the horizontal and tilted surface, solar fraction, greenhouse gas emissions, and energy savings are used for comparative analysis of different types of solar collectors while net present value, payback period, benefit to cost ratio, and annual life cycle savings are the deciding factors for economic viability of these systems. Results indicate that under same prevailing conditions Bisha is the most attractive while Tabuk is the least suitable place for solar SWH technology.

Decentralized and cost-effective solar water purification system for remote communities

In this study, a modified stepped solar still is proposed for water desalination. The overall objective of this work is to develop and test the proposed still design to identify the productivity enhancement as compared to conventional basin type solar still. The proposed design takes the advantage of its stepped configuration that allows the water stream to maintain a minimum desirable water column height and the water flow through the stages under the force of gravity. A minimum water depth in the still results in a higher rate of evaporation. The still is also incorporated with Fresnel lens to increase the water temperature that eventually increases the rate of water evaporation. Another important aspect of this design is the incorporation of phase-change-material (PCM) to increase the operational hours of the solar still. Consequently, daily productivity of fresh water is increased.