Design and Evaluation of a Low-Cost Solar Water Heating System

Thesis Abstract

The escalating demand for affordable and sustainable hot water solutions in residential and small-scale commercial settings underscores the necessity for innovative, cost-effective renewable energy systems, particularly in regions constrained by economic and infrastructural limitations. This study aims to develop and rigorously evaluate a low-cost solar water heating (SWH) system that balances affordability with efficiency, thereby contributing to energy accessibility and environmental sustainability. The specific objectives include designing an economically feasible solar collector and storage system, assessing its thermal efficiency under varying climatic conditions, and evaluating user acceptability and operational reliability over a six-month operational period. Employing a mixed-methods research design, the study integrates quantitative experimental testing with qualitative user feedback. The quantitative component involves constructing a prototype SWH unit using locally available materials and deploying it in a pilot household sample comprising 30 homes within a semi-urban region. Data collection instruments include digital temperature sensors, flow meters, and energy meters to record parameters such as water temperature rise, heat retention capacity, and overall system efficiency. Additional qualitative data are obtained through semi-structured interviews and user satisfaction surveys, designed to capture operational experiences and perceived benefits. Data analysis involves descriptive statistics, inferential techniques such as regression analysis to identify factors influencing system efficiency, and thematic analysis for qualitative insights. The analytical framework is grounded in the principles of the Sustainable Design Theory and the Technology Acceptance Model, which inform the evaluation of technical performance and user adoption. Anticipated findings indicate that the designed low-cost SWH system can achieve thermal efficiencies comparable to commercial units—projected at around 50-55%—by utilizing locally sourced evacuated tube collectors and simple insulation techniques. The regression analysis is expected to reveal that climatic variables such as solar insolation significantly influence performance metrics, while user surveys are likely to demonstrate high levels of satisfaction and willingness to adopt the system for domestic hot water needs. The study aims to identify practical design modifications that enhance thermal retention and durability, especially in semi-urban environments where sunlight availability varies seasonally. This research contributes novel insights into affordable renewable energy technologies by demonstrating that cost-effective materials and locally adaptable designs can produce reliable solar water heating solutions suitable for low-income settings. The application of empirical performance data coupled with user-centered evaluation fills a critical gap in the literature, which predominantly focuses on commercially available systems or high-cost prototypes. The integration of technical performance metrics with user acceptance models advances understanding of the socio-technical factors influencing renewable energy adoption in developing regions. Concluding, the study affirms that a sustainably designed, low-cost SWH system is both technically feasible and socially acceptable, paving the way for broader dissemination and adoption in resource-constrained communities. Recommendations include scaling the prototype for wider deployment, further optimizing system ergonomics, and incorporating local manufacturing to reduce costs. Additional research avenues suggested encompass long-term durability assessments, integration with existing water supply infrastructure, and the exploration of energy storage innovations. Overall, the findings advocate for policy initiatives that promote affordable renewable energy solutions, thereby contributing to energy equity, environmental conservation, and economic development in developing regions.