In this paper, the authors have calculated the cumulative energy demand and cumulative greenhouse effect for three renewable energy technologies, namely, wind energy, solar photovoltaic, and solar water heating (SWH) system, corresponding to typical climatic conditions in India. The life cycle assessment of these systems (1.5 MW windmill, 35W (P) SPV, 2 m(2) and 100 lt. SWH systems) has yielded the parameters energy yield ratio (EYR) and emission coefficient. EYR for these three technologies are found to be from 9.59 to 31.11, 0.58 to 0.91, and 2.32 to 7.14, respectively. Variation of emission coefficients is from 2.40 to 7.86, 83.72 to 133.10, and 19.88 to 61.06 kg CO2 per GJ delivered from the three technologies, respectively. Their corresponding correlation has been fitted with an algebraic expression having a correlation coefficient of 0.91.