The work in this paper contributes to the fairly limited literature on this field of science. Among the few studies comparing the environmental performance between hydropower (small and large), wind power and other electricity generation options, Evans et al. (2009) concluded that wind power is the most sustainable, followed by hydropower, photovoltaics (solar power) and then geothermal. The parameters used for comparison in this comparison were costs, greenhouse gas emission, availability of sources, efficiency of energy conversion, land requirements, water consumption and social impacts.