Limits to co-combustion of coal and eucalyptus due to water availability in the state of Rio Grande do Sul, Brazil.

•Brazil holds reserves of high ash coal that can only be used in mine-mouth plants.•Water scarcity requires the use of wet or dry cooling systems in several regions.•The co-firing of 30wt% eucalyptus is possible regarding the biomass availability.•Biomass cultivation would aggravate the water scarcity in several regions.