All introduced in Russian Federation information and technical reference books on the best available technologies (BAT) for various processes of steel industry have acceptable maximum values of harmful substances emission. The first experience of BAT application revealed a problem of matching of energy and ecology effectiveness. For its solving, a comprehensive criterion proposed for selection of BAT by minimum end-to-end technological fuel ecological greenhouse number, which at the same time characterizes energy intensity, ecological losses of a plant and emission of greenhouse gases of a technological product. In the proposed methodology, the ecological losses and greenhouse gases emission is expressed in energy units, that enables to compare a product energy intensity, determined before for various plants, with the losses resulted in harmful and greenhouse gases emissions. A concept of "technological fuel number" (TFN), determined as summery consumption of all kinds of energy in the considered and in all the previous technological processes less TFN, formed by secondary energy resources. Values of TFN for various kinds of products of steel industry plants and resources, used for their production quoted, as well as values of normative payment for harmful substances emission and their specific emissions in steel industry.