NOVELTY - The cogeneration installation comprises a furnace for the combustion of biomass that emits fumes to vaporize an organic fluid whose vapors drive a turbine to produce electricity, and a vapor condenser placed at an outlet of the turbine. The organic fluid operates according to a Rankine cycle at a hot source temperature of greater than 300 degrees C, is vaporized in a first exchanger (5), and has a temperature of 270 degrees C at the inlet of the turbine and a pressure of 15 bars. The combustion furnace is a sludge incinerator (3) for water treatment. The sludge incinerator is a hot wind box incinerator.    USE - The cogeneration installation is useful for producing electrical energy and thermal energy from biomass.    ADVANTAGE - The installation ensures efficient production of electrical energy and thermal energy from biomass without any environmental risk.    DETAILED DESCRIPTION - The cogeneration installation comprises a furnace for the combustion of biomass that emits fumes to vaporize an organic fluid whose vapors drive a turbine to produce electricity, and a vapor condenser placed at an outlet of the turbine. The organic fluid operates according to a Rankine cycle at a hot source temperature of greater than 300 degrees C, is vaporized in a first exchanger (5), and has a temperature of 270 degrees C at the inlet of the turbine and a pressure of 15 bars. The combustion furnace is a sludge incinerator (3) for water treatment. The sludge incinerator is a hot wind box incinerator. The first exchanger is crossed by the fumes of the incinerator and by a heat-transfer fluid that is heated by the fumes in a second heat exchanger. Cold fluid obtained from the condenser is constituted by cooling water having a temperature of 85-95 degrees C. Recovered energy, during the condensation of the fluid at the outlet of the condenser, is sent to sludge drier.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of an installation.    Drier (2)    Incinerator (3)    Conduit (4)    First heat exchanger (5)    Another conduit. (6)