Comparison of aluminium and stainless steel built-in-storage solar water heater

This article provides the results and findings of an experimental work undertaken in Pakistan that aimed to compare the performance of stainless steel and aluminium make built-in-storage solar waters. The experimental work under-taken as part of this project included design and development of the 2 solar water heaters as well as their operation and data collation over a period of 2 months. The results of the experimental work have been rigorously analysed to present detailed ecological and financial accounts of the two heaters. The results indicate that the aluminium heater performs better than the stainless steel heater in every respect. The average annual daily energy output from stainless steel and aluminium heaters is calculated to be 2.3 kWh and 2.9 kWh giving respective efficiencies of 47% and 61%. It has been shown that over the life cycle of 20 years, the stainless steel and the aluminium solar water heaters are capable of respectively producing 16.5 MWh and 21.3 MWh of energy. For industrial applications, the monetary payback period for the stainless steel and aluminium heaters has been found to be equivalent to 3.9 years and 1.4 years, respectively. It has also been shown that over the life time the stainless steel and aluminium solar water heaters are capable of respectively saving as much as 1.9 and 2.5 tonnes of Carbon per m² aperture area. Practical applications: Renewable energy is one of the prominent solutions to address the emerging energy and environmental challenges. Solar water heating is amongst the fastest growing renewable technologies in the world. The article provides a detailed account of the technical and economical parameters of the built-in-storage type of solar water heaters. The findings of the work would be of great interest for researchers, professionals such as building services engineers and architects, and entrepreneurs. The article also finds its significance as the UK has decided to promote low-carbon housing and solar water heating can be an ideal technology in achieving any such goals.