Biomass cofiring refers to combustion of biomass along with coal in a thermal power plant to reduce the amount of carbon dioxide released. There are 3 types of biomass cofiring: direct combustion, indirect combustion and parallel combustion. The biomass has to be treated before combining with coal in order to improve the boiler efficiency.

The cofiring of biomass with coal has the following environmental benefits:

1. Cofiring reduces the carbon dioxide emissions which is a major contributor to global warming.
2. Sulphur content in biomass is low and hence cofiring will reduce the emission of oxides of sulphur like sulphur dioxide that contributes to acid rain.
3. Some of the tests conducted on biomass cofiring showed a reduction of 30% in oxides of nitrogen.
4. Cofiring in coal plants would strongly increase biomass use.
5. Biomass cofiring also reduces the dependency on fossil fuels and thereby increases the share of renewable energy.

Some of the challenges facing the adoption of cofiring include technical challenges in the modification required in the burner, fuel handling and storage systems to accommodate the biomass, limited availability of biomass, loss in boiler efficiency due to high moisture content in the biomass, disposal of ash generated in the process, and the underdeveloped biomass supply market which restricts the widespread use in cofiring.