NOVELTY - The assembly has electrolyzer (2) that produces hydrogen from water using electrical current of external electricity unit. A first chemical reactor (3) performs partial hydrogenation of substrate with extended pi-conjugated system using hydrogen. A storage tank (4) stores partially hydrogenated substrate. Dehydrogenation of partially hydrogenated substrate is performed in second chemical reactor (5) using hydrogen. A gas cell (6) is provided for oxidizing hydrogen in the second chemical reactor so as to release energy which is used by external electricity unit of building.    USE - Assembly for supplying energy to building. Uses include but are not limited to private house, rented flat, holiday resort, commercially used real estate and factory.    ADVANTAGE - Energy can be supplied to the building is cost-effective manner. The efficiency of the energy supplying assembly is improved. The structure of the energy supplying assembly is simplified. The durability of the energy supplying assembly is improved. The energy supplying assembly can be maintained easily.    DETAILED DESCRIPTION - The assembly has gas cell such as low temperature polymer electrolyte diaphragm gas cell. The oxygen required for oxidizing process is fed from the exterior of gas cell in the form of air. A backup supply is arranged to provide additional electric current from gas cell to external electricity unit. An INDEPENDENT CLAIM is included for method for supplying energy to building. POLYMERS - The substrate is comprised with polycyclic aromatic hydrocarbon, polycyclic heteroaromatic hydrocarbon, and/or ( pi )-conjugated organic polymer, or fused 12C heteroaryl optionally containing heteroatoms chosen from N, S or O, in which heteroatom is optionally substituted by 2-5C alkyl, aryl, alkenyl, alkynyl, cycloalkyl and/or cycloalkylene, more preferably N-ethylcarbazole, N,N-propylcarbazole or N-iso-propylcarbazol. The substrate is hydrogenated in primary reactor at 50-180 degrees C under pressure of 2-200 bar in presence of a catalyst.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the assembly for supplying energy to building. (Drawing includes non-English language text)    Electrolyzer (2)    First chemical reactor (3)    Storage tank (4)    Second chemical reactor (5)    Gas cell (6)