TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Process: The pile is wetted with water, liquid manure or percolates of other digestion processes. The transfer is provided of the percolate and biogas from the base of the pile to at least one hermetically sealed well (5), where gas and liquid are separated. The recycling is provided of the percolate with distribution at the top of the pile. The top of the pile aspiration is provided of biogas or the blowing of air. The agricultural waste is in the form of bales. In the process, after the phase of aerobic pre-treatment, addition of slurry, which is rich in cellulosic methanogenic bacteria, is provided. The recycling is provided on agricultural land of the residual composted material containing all the nutritional elements removed from the soil.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The platform is formed by a layer of clay (1), where a waterproof containment membrane (2), a layer of sand (3) and a layer of cement are placed on it. The means for collection of the percolate and biogas comprises a comb collector formed by a series of porous pipes intercalated between the bales and protected by sand or gravel, placed at a slight slant on the platform and leading into a watertight well, where separation between the gas and liquid takes place. The means for recycling and distribution of the percolate comprise a pump for aspiration from the well, a recycling pipe and a comb distributor. The means for aspiration of the biogas from the top of the pile or through blowing of air comprises an aspiration fan and a grille collector for aspiration of the biogas, connected on one side to a collector, where a cut-off valve is placed on it and on the other side to the atmosphere via a valve, in such a way that by opening the cut-off valve and closing the valve the biogas is aspirated from the pile and by closing the cut-off valve and opening the valve air is blown into the pile. In the system, waterproofing of the system is obtained by covering the pile with a polyethylene membrane which is sealed to the lower containment membrane by welds. In the system, a means is provided for feeding the well of the percolate with water, liquid manure of percolates of other digestion processes, for later recirculation in the pile by means of the pump. EXAMPLE - Pile of straw bales (having a square base of 57 m per side and a height of 12 m) was formed on the cement platform (size 3600 m2) with containment sheet and at the end of banking-up, covered with a sheet welded along the sides with sheath/sheet of the base. After sealing, wetting was performed with water (700 m3) and the aerobic phase was carried out to activate the hydrolysis phase and the temperature of the pile was raised to 30-40 degrees C. After reaching the temperature, strict anaerobic conditions were established and slurry (50 m3) that was rich in cellulosic methanogenic bacteria was added to the pile. In case of lowering of temperature at very cold times, air was allowed to aspirate to ensure sufficient percentage of aerobic operation in order to maintain the optimal temperature. The estimated biogas production was 1800000-2000000 Nm3/year with a methane content of greater than 50%, and the obtained biogas was fed to an internal combustion engine with alternator to produce a power equal to 370-420 kW of electrical energy.