Coal-powered plants account for around 42.2 percent of that capacity, with diesel-fired plants 23.7 percent, gas 22 percent, hydropower plants 6.7 percent and geothermal and other renewable energy at 5.4 percent. — Excerpt from The Jakarta Globe
I personally think that coal power plants will still play major role in 10 years due to lower capex for development. Challenges to balanced energy mix would be economic scale and ROI. If new technology offers lower development cost then energy mix portion will shift to non-coal based.