NOVELTY - System comprises an algae cultivation plant (D) to produce biomass from algae, an oil press (I) plant to produce oil and proteins from biomass, a biofuel processing station (J) to produce biodiesel from oil, a feed mill (K) to produce animal feed, a tank for biomass made from agricultural raw materials, preferably to store the residue from the feed-, oil production and agricultural materials, a biogas plant (A), a separator, a pellet/fertilizer plant to obtain pellet/fertilizer from the solid matter fraction, and a cogeneration station.    USE - The system is useful for generating and using renewable energy, to produce electrical- and thermal energy from biogas from agricultural raw materials, and pellet/fertilizer from production residues of solid fraction (claimed).    ADVANTAGE - The system is closed (claimed), and prevents uncontrolled emission of carbon dioxide into the atmosphere and so is environmentally friendly.    DETAILED DESCRIPTION - System comprises an algae cultivation plant (D) to produce biomass from algae, an oil press (I) plant to produce oil and proteins from biomass, a biofuel processing station (J) to produce biodiesel from oil, a feed mill (K) to produce animal feed, a tank for biomass made from agricultural raw materials, preferably to store the residue from the feed-, oil production and agricultural materials, a biogas plant (A) to produce biogas and fermentation mass from biomass, a separator to produce fluid fraction directed as a medium to the algae cultivation station, and the solid matter fraction, a pellet/fertilizer plant to obtain pellet/fertilizer from the solid matter fraction, and a cogeneration station to obtain electrical energy, heat and waste gases from biogas. The heat energy is distributed for pellet/fertilizer plant and the algae cultivation plant. The waste gases are directed into the algae cultivation plant and a transformer-distribution station in which electrical energy is distributed for the pellet/fertilizer plant, the external network and the algae cultivation plant.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the system.    Biogas plant (A)    Algae cultivation plant (D)    Oil press (I)    Biofuel processing station (J)    Feed mill (K)