With the PROGRASS® approach previously unused grassland biomass is converted to energy by the IFBB technique. About 45% of the energy stored in the biomass are transformed into exportable heat. If the IFBB plant is constructed as an add-on to an existing biogas plant, the waste heat of the biogas plant can be utilized for drying the press cake. This enhances the energy efficiency to about 53%. The biogas gain by fermentation of the press fluid meets the additional electricity demand of the IFBB technology .

Even, if the fuel consumption for transport and mowing is included, the energy balance remains positive.

The highest potential savings of fossil fuel and greenhouse gas emissions are obtained in an integrated system where the IFBB technique is combined with a biogas plant (IFBB add-on). An independent IFBB plant (IFBB stand-alone) and hay combustion exhibit similar energy and greenhouse gas balances, but not as favourable as an IFFB add-on. The exclusive biogas recovery by dry fermentation offers the lowest saving potentials because of the minor digestibility of the green-cut of semi-natural grasslands.