The paper proposes the usage of carbon-containing waste of industrial enterprises in producing the solid fuel for energy purposes. The surplus activated sludge from the city sewage treatment facilities is applied as a binder. The paper determines the optimal composition of fuel to use in solid-fuel boilers and develops the technological scheme of the experimental setup. The proposed technology will contribute to resource - and energy saving. The resource saving includes the usage of biogas and fuel pellets as an alternative to traditional natural energy resources: coal, natural gas, etc. It is prospective to use pellets as the solid fuel instead of coal in boiler plants and for human needs. Energy saving implies significant reduction of external energy consumption in order to implement the proposed solutions, which is possible due to the usage of one’s own produced gas and solid fuel.