As a means of reducing coal consumption and thereby fossil fuel derived CO{sub 2} emission, Stockholm Energi AB has initiated a study, together with ABB Carbon, into the co-firing of a number of candidate biomass fuels in PFBC. The study includes testing of the fuels at the ABB Carbon 1 MW Process Test Facility. Up to 40% by weight of the fuel was biomass and the fuels tested were wood chips, olive pips and palm nut shells, all of which are commercially available fuels. The results of these tests are presented and indicated no significant deviations in process behavior when co-firing biomass compared to operation with 100% coal. Given the correct fuel pricing, the use of biomass in PFBC would be an attractive alternative for heat and power generation from biomass.