Abstract: This study was carried out to compare three renewable energy based water disinfection methods (boiling, solar disinfection and granular activated carbon filtration) for developing countries, in order to estimate which is cost effective. A very large segment of the world's population is without microbiologically safe water supply. Obtaining clean drinking water is a constant challenge in many countries. Often the only water available is rife with disease-causing bacteria and must be disinfected to make it safe. The lack of money needed to develop the elaborate drinking water infrastructure in addition to the difficulty or impossibility associated with importing materials and expertise necessary for sustainable operation of such facilities demand techniques capable of eliminating or neutralizing water-borne pathogens using little or no external input such as capital, material, expertise etc. The water samples for this study were collected from Aso River and a borehole both in Nsukka into two containers. These water sources are used by the villagers. The control and treated samples were collected and analysed for coliform and total viable count, using modified method of Miles and Misra. The results showed that the best means of water disinfection is boiling which destroyed all the coliform in the water samples while the use of solar could be considered a cheaper alternative although it did not eliminate completely the microbial load impeding suitability for drinking. However, granular activated carbon filtration should be discouraged, as it had a negative effect of increasing the microbial load of the water samples.