Solar Water Heating Systems Performance with Different Enhancement Techniques: A Detailed Review

Considering the global fuel crisis, countries have made it imperative to exploit solar energy correctly, which has emerged as the most significant renewable energy source in recent times. Utilizing solar energy to heat the water appropriately to reduce global energy consumption is a challenge most countries face. Research has, therefore, been done extensively to maximize the performance of solar water heating through various applications. Several methods were enumerated and applied in this review study to determine how to enhance the performance of solar water heaters. Eleven techniques for improvement were identified. They are as follows: using nanofluid with phase change material; improving the collector design; coating; lowering the inlet water temperature; switching to a combined system in place of the conventional gas heating system; utilizing a dual glass cover; utilizing the upstream delta wing; utilizing the evacuated tube collector; utilizing the heat exchanger; utilizing the photovoltaic glass unit; and integrating the solar water heater and tubular lighting device into one unit. According to the essential results, using an absorption cooling system with solar power resulted in 34% electricity savings. The absorption system was enhanced, and the COP was raised to 2.75 by implementing the solar water heating system. Solar heating systems combined with PCM achieved the highest efficiency rating of 65%. The dryer system’s CO₂ emissions were lowered by about 34% when adding a solar collector. The solar water heater’s thermal efficiency was increased by 22.53% by a CuO/H₂O nanofluid.