Coal requirement has been worked out considering 30% reduction in hydro generation due to failure of monsoon
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/national-electricity-plan-revised-make-room-more-coal
[2] http://admin.indiaenvironmentportal.org.in/category/author/shreya-jai
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/business-standard-new-delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coal
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hydroelectricity
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/electricity
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/renewable-energy
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/wind-energy
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-dioxide
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/energy