The global power sector will change significantly in the coming years, as variable renewable resources are deployed on a large scale and new flexibility options appear, such as energy storage devices. In this context, thermal plants that use fossil fuels will experience a reduction in their share of power sector output, particularly in advanced economies, as efforts to achieve climate goals are increased. In developing economies, overall electricity demand will increase as power demand is pushed up by economic growth, urbanisation and increasing energy access. This report clarifies the role that thermal plants will play in the power systems of emerging economies in different IEA scenarios, including the Stated Policies Scenario and Sustainable Development Scenario of the 2019 World Energy Outlook. International co-operation and knowledge sharing can play significant roles in helping emerging economies carry out an affordable energy transition.