TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The path comprises many passageways. The passageways are: adjacent to one another; rectangular; defined by least one upright divider; cylindrical; or concentric to one another. In the system: each divider projects upwardly from a base of the digestion reservoir; each mixing assembly comprises a vertical structure, where the vertical structure has a first opening fluidly connected to a first given passageway of the path of the digestion reservoir, and the vertical structure has a second opening fluidly connected to a second given passageway of the path of the digestion reservoir; each mixing assembly comprises a pair of first and second vertical structures, where the first and second openings of the first vertical structure is respectively bottom and top openings, and the first and second openings of the second vertical structure is respectively top and bottom openings; each given vertical structure comprises a cover for selectively allowing access to an inside portion of the given vertical structure; each mixing assembly is located at a distal end of a given divider, where openings of the mixing assembly are fluidly connectable to adjacent passageways through the given divider; each mixing assembly comprises at least one agitation unit for locally mixing biomass being conveyed along the path and traveling about the agitation unit; each agitation unit is provided with a mixing device; a level of biomass contained in a given passageway of the digestion reservoir is maintained above a corresponding opening of the mixing assembly associated to the given passageway so as to prevent biogas from escaping the system via the mixing assembly; a level of biomass contained in the digestion reservoir is maintained above an uppermost opening of the mixing assembly of the system so as to prevent biogas from escaping the system via the mixing assembly; digestion bacteria is introduced into the digestion reservoir; biogas produced from the system is recuperated and converted into electrical energy; and biogas produced from the system is recuperated and stored into thermal energy. The digestion reservoir is impermeable to fluids. The digestion reservoir comprises a dome for retraining biogas produced from the system. The first opening is a bottom opening and the second opening is a top opening. The first opening is a top opening and the second opening is a bottom opening. The first and second vertical structures are adjacent to one another. The mixing device is positioned adjacent to a given opening of a given mixing assembly. The system comprises: a hydrolysis pit for providing the digestion reservoir with biomass; at least one pump for pumping biomass from the hydrolysis pit to the digestion reservoir; an evacuation pit for receiving digested biomass from the outlet of the digestion reservoir; at least one pump for pumping digested biomass out from the system; a temperature-regulating system provided about the digestion reservoir; a temperature-regulating system provided about the hydrolysis pit; an energy storage unit for storing thermal energy; a hot water pit for receiving heat from burnt biogas via a heat exchanging unit conducting the burnt biogas; and a temperature-regulating system provided about the hot water pit. The digestion reservoir comprises a downwardly-sloping base, where biomass is conveyed along the path of the digestion reservoir by gravity via the downwardly-sloping base. The energy storage unit comprises a burner for burning biogas produced by the system. The hot water pit is operatively connected to at least one neighboring greenhouse, where the neighboring greenhouse has a floor circuit heated by means of hot water provided by the hot water pit.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The biomass is agricultural liquid manure provided by at least one neighboring farm operatively connected to the hydrolysis pit of the system via at least on inflow pipe. Preferred Method: The biomass is conveyed along the path of the digestion reservoir via an inflow of new biomass at the inlet of the digestion reservoir and via an outflow of old biomass at the outlet of the digestion reservoir. The biomass is conveyed along the path of the digestion reservoir via a mechanical conveyance. The biomass is digested along the path of the digestion reservoir by a natural process. The biomass is digested along the path of the digestion reservoir by an assisted process. The biomass is digested along the path of the digestion reservoir during 30 days. The method comprises: agitating biomass at discrete locations along the path; introducing beneficial bacteria into the digestion reservoir; regulating the temperature of the digestion reservoir; maintaining the biomass at 100 degrees F; and recuperating biogas produced by the system and converting it into usable energy. The step (b) comprises digesting biomass during 30 days.