This project explores the design of a portable solar water heater optimized for high-efficiency heat transfer in off-grid settings. The system utilizes the superior thermal conductivity of copper turnings, which serve as a heat exchanger to capture direct solar radiation. Using a closed-loop mechanism, a small pump circulates water from a storage tank through these copper coils, where it is rapidly heated before returning to the reservoir.

This active circulation ensures consistent temperature elevation and prevents heat loss associated with passive designs. Compact and lightweight, the prototype provides a sustainable solution for hot water needs in camping or emergency relief scenarios. By combining copper’s material efficiency with a motorized flow, the system delivers a reliable, eco-friendly energy alternative. In addition to its functional design, the proposed system emphasizes affordability and ease of fabrication, making it suitable for deployment in resource-constrained environments. The use of readily available copper turnings reduces material costs while maximizing surface area for heat absorption, thereby enhancing overall thermal performance. The closed-loop configuration also minimizes water wastage and contamination, ensuring hygienic operation even in remote locations.

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1. H. P. Garg & J. Prakash, Solar Energy: Fundamentals and Applications, Tata McGraw-Hill, New Delhi, 2012.
2. S. P. Sukhatme & J. K. Nayak, Solar Energy: Principles of Thermal Collection and Storage, McGraw-Hill Education, 3rd Edition, 2017.
3. G. N. Tiwari, Solar Thermal Energy Utilization, Oxford & IBH Publishing, New Delhi, 2014.
4. Duffie, J. A., & Beckman, W. A., Solar Engineering of Thermal Processes, Wiley Publications, 4th Edition, 2013.
5. Kalogirou, S. A., “Solar Thermal Collectors and Applications,” Progress in Energy and Combustion Science, Vol. 30, pp. 231–295, Elsevier, 2004.
6. Tripathi, R., & Tiwari, G. N., “Thermal Modeling of a Solar Water Heater,” International Journal of Renewable Energy Research, Vol. 6, Issue 2, 2016.
7. Malhotra, A., “Design and Performance Evaluation of Solar Water Heating Systems,” International Journal of Engineering Research & Technology (IJERT), Vol. 5, Issue 8, 2016.
8. Ministry of New and Renewable Energy (MNRE), Government of India, “Solar Water Heating Systems – Technical Guidelines,” MNRE Standards, 2021.
9. BIS (Bureau of Indian Standards), “IS 12933 – Specification for Solar Flat Plate Collectors,” Bureau of Indian Standards, New Delhi.
10. National Renewable Energy Laboratory (NREL), “Solar Thermal Technologies Overview,” U.S. Department of Energy.
11. Solar Energy Society of India (SESI), Technical Papers and Reports, 2020–2024.
12. Technical documentation and product standards from manufacturers for copper tubes, reflectors, DC pumps, and GI tanks (e.g., Jindal, Kirloskar, Crompton, etc.).
13. Duffie, J.A. and Beckman, W.A., Solar Engineering of Thermal Processes, 4th Edition, Wiley, 2013.
14. Weather-2-Visit. (2025). Hubli Weather in November 2025 | India Averages.
15. Understanding solar radiation: earth’s powerful energy source(HVAC-R & Solar Engineering Resource, 26 April 2019)

This project explores the design of a portable solar water heater optimized for high-efficiency heat transfer in off-grid settings. The system utilizes the superior thermal conductivity of copper turnings, which serve as a heat exchanger to capture direct solar radiation. Using a closed-loop mechanism, a small pump circulates water from a storage tank through these copper coils, where it is rapidly heated before returning to the reservoir.

This active circulation ensures consistent temperature elevation and prevents heat loss associated with passive designs. Compact and lightweight, the prototype provides a sustainable solution for hot water needs in camping or emergency relief scenarios. By combining copper’s material efficiency with a motorized flow, the system delivers a reliable, eco-friendly energy alternative. In addition to its functional design, the proposed system emphasizes affordability and ease of fabrication, making it suitable for deployment in resource-constrained environments. The use of readily available copper turnings reduces material costs while maximizing surface area for heat absorption, thereby enhancing overall thermal performance. The closed-loop configuration also minimizes water wastage and contamination, ensuring hygienic operation even in remote locations.

🔒 This is a subscription article

Full text is available to subscribers and institutional members. Please choose an option below to access it.

1. H. P. Garg & J. Prakash, Solar Energy: Fundamentals and Applications, Tata McGraw-Hill, New Delhi, 2012.
2. S. P. Sukhatme & J. K. Nayak, Solar Energy: Principles of Thermal Collection and Storage, McGraw-Hill Education, 3rd Edition, 2017.
3. G. N. Tiwari, Solar Thermal Energy Utilization, Oxford & IBH Publishing, New Delhi, 2014.
4. Duffie, J. A., & Beckman, W. A., Solar Engineering of Thermal Processes, Wiley Publications, 4th Edition, 2013.
5. Kalogirou, S. A., “Solar Thermal Collectors and Applications,” Progress in Energy and Combustion Science, Vol. 30, pp. 231–295, Elsevier, 2004.
6. Tripathi, R., & Tiwari, G. N., “Thermal Modeling of a Solar Water Heater,” International Journal of Renewable Energy Research, Vol. 6, Issue 2, 2016.
7. Malhotra, A., “Design and Performance Evaluation of Solar Water Heating Systems,” International Journal of Engineering Research & Technology (IJERT), Vol. 5, Issue 8, 2016.
8. Ministry of New and Renewable Energy (MNRE), Government of India, “Solar Water Heating Systems – Technical Guidelines,” MNRE Standards, 2021.
9. BIS (Bureau of Indian Standards), “IS 12933 – Specification for Solar Flat Plate Collectors,” Bureau of Indian Standards, New Delhi.
10. National Renewable Energy Laboratory (NREL), “Solar Thermal Technologies Overview,” U.S. Department of Energy.
11. Solar Energy Society of India (SESI), Technical Papers and Reports, 2020–2024.
12. Technical documentation and product standards from manufacturers for copper tubes, reflectors, DC pumps, and GI tanks (e.g., Jindal, Kirloskar, Crompton, etc.).
13. Duffie, J.A. and Beckman, W.A., Solar Engineering of Thermal Processes, 4th Edition, Wiley, 2013.
14. Weather-2-Visit. (2025). Hubli Weather in November 2025 | India Averages.
15. Understanding solar radiation: earth’s powerful energy source(HVAC-R & Solar Engineering Resource, 26 April 2019)