This study involved investigation of solar water disinfection in continuously working treatment plants with the aim of producing safe drinking water in isolated areas. Results were obtained from experimental work carried out on a pilot plant operating in different configurations. The use of a simple device to increase solar radiation intensity (solar concentrator) was tested, with results showing that it facilitated better performance. A comparison between transparent and black-painted glass reactors was also made, showing no difference between the two casings. Further, the effect of an increase in water temperature was analysed in detail. Temperature was found to play an important role in the disinfection process, even in cases of limited solar radiation intensities, although a synergistic effect of water heating and solar radiation for effective microbial inactivation was confirmed. Reactor design is also discussed, highlighting the importance of having a plug flow to avoid zones that do not contribute to the overall effectiveness of the process.