Handbook of SOFC system in buildings: Legislation, standards and requirements

This publication is aimed at supporting the installation and exploitation of 50 kW SOFC in an office building. In this context, the standardisation situation has been scanned worldwide. Requirements concerning connection of the SOFC system to the public networks have been explored and solutions consulted with authorities and owners of the local natural gas, heating and electricity networks. Installed fuel cell systems must be CE marked and comply with a set of European Union directives. The group of standards related to stationary systems produced by the IEC TC 105 committee is the most important regulatory base for application preparation. A fuel cell power system and associated equipment, components, and controls shall be sited and installed in accordance with the manufacturer's instructions. A written fire prevention and emergency plan shall be provided as required by and in accordance with national standards. The room or area where the fuel cell power system is installed shall have a hydrogen detector. A new proposal has been developed, which combines a fuel cell system with the otherwise typical district heating connection scheme in Finland. Materials in connection with this must be carefully selected in the primary and secondary side to qualify for the whole life cycle. It must be possible to measure energy consumption in both directions (buy/sell mode). There are important requirements concerning electric energy-generating units. All exposed conductive parts of the electric power system shall be connected to the main earthing terminal or bar. If the neutral conductor exists it shall be connected at the network supply end to the main earthing terminal. The output filters of an interconnection device may not cause resonances with the rest of the electric grid. The interference with the grid operation is not allowed by any other reactive components that may cause changes in the operating parameters of the filters. The systems equipped with an inverter may be connected into the network without a separate synchronising device. The short-circuit power of the coupling point should be 25 times the rated power of a generating unit.