Method for the use of waste, in particular solid waste, in a thermal power station wherein the primary energy is supplied by combustion of fossil fuels with input of combustion air, which said method is characterized in that it comprises combustion of the waste with an air flow suitably controlled so that combustion is approximately complete, cooling of the burnt gases by means of at least partial mixing with cold air to a pre-determined temperature which is lower than the maximum temperature compatible with cleaning, cleaning of the cooled burnt gases, and mixing of said cooled, cleaned burnt gases with the combustion air used in the power station so as to transfer a part of the thermal energy generated by waste combustion to said combustion air, the remaining part being transferred by the waste combustor cooling fluid and/or excess gas to power station boiler water recycle.
Before the combustion, the solid waste may be pre-treated to give a secondary fuel; said pre-treatment comprises at least one phase of forced aerobic fermentation and one phase of metals or inerts extraction.