Plastics wastes from a municipal solid waste (MSW) plant have a high-energy content and are suitable for co-processing with coal. The addition of 5% plastic waste to a coal-fired PF power station reduces its efficiency slightly from 44.0 to 43.7% due to the high moisture content of the plastics. The overall economics however can be favourable. For the cost of electricity to be the same as the coal only case, the plastic waste could have a value of up to 23 E/dry tonne to the power station, assuming that it had been prepared for use. Therefore the maximum amount that the power station can afford to spend on preparing the plastic waste for use is 23 C/dry tonne plus the avoided landfill cost, less the transport cost. The location of the power station plays a key role, since this does not only have an effect on the transport costs of the waste but also on the landfill charges. The sensitivity of the economics of co-processing plastic waste with coal for a variety of power station operational parameters is presented.