The study provides the basic parameters and technical coefficients of the cost benefit analysis model for the socio-economic and environmental impact of introducing a renewable energy source (Hydroelectric) that replaced the conventional depleted fuel source. The study applied this model for quantitative profile of the socio-economic and environmental impact as net present value of replacement the conventional depleted fuel for a renewable energy source. It shows that the avoidance of premature mortality is the main source of benefits, even though it is an external benefit, which in most feasibility studies is ignored