This paper describes the studyundertaken to assist the government of Sri Lanka inidentifying a path toward sustainable power development. Thetiming of the report is important, as Sri Lanka is about toembark on the development of coal-fired power plants overthe coming years. The purpose of this study is to determinehow much cheaper coal-fired generation is than other energysources; how much more environmentally friendly are thealternatives; what impacts would be more environmentallyfriendly; and what effect would the policies have on powersector costs and electricity tariffs. The report seeks toprovide a quantitative analysis that will helpdecision-makers assess various power sector policy optionsin terms of the trade-offs between environment, costs, andother impacts. The study makes recommendations only ifoptions are unambiguously winwin; but more often than not,tradeoffs are required, and ultimately the government mustdecide what it considers to be more important. A number ofalternative policies and technologies were systematicallyanalysed, and the report gives a brief description of each option.