When balancing the objectives of affordability, reliability and environmental sustainability of energy supply, the answer in developing Asian economies has historically been unequivocal: Coal is king. This is because these nations placed greater emphasis on the first two objectives at the expense of the third. However, coal markets in Asia now face increasing community pressures for better local air quality and, to a lesser extent, concerns about global climate change. Consequently, policymakers are struggling to find a new optimal energy mix, which preserves the economic benefits of cheap coal but also helps them adhere to increasingly stringent emission norms and climate accords.