Domat Control System takes part in an interesting project of production and usage of hydrogen from renewables. In the Nuclear research institute Řež there was built an experimental plant containing a PV power plant, accumulatiors, hydrogen generator, hydrogen fuel cell, and inverters for supplying of the grid. The hydrogen storage tank has 10 m3 volume, and stores hydrogen pressurized up to 15 bar. In the control system it is possible to program different control strategies for optimum utilization of the form of energy which is the cheapest: if there is abundance of solar irradiation, the PV plant energy is converted to AC and fed into the grid. If the grid consumption is lower than the momentary capacity of the PV plant, the extra energy is stored in the accumulators in daily cycles, or brought to the hydrogen generator, as hydrogen may be stored on a long-term basis. If the PV plant output power is insufficient, or grid consumption is high, the fuel cell operation is enabled, which converts hydrogen to DC. The direct current is inverted and fed into the grid. Other I/Os of the MXIO module monitor temperature and pressures in the piping and hydrogen storage tank, keep proper temperature in the machinery rooms etc.
In the next stage, weather forecast model data utilisation is planned. This service has been available for several years as RcWare Weather, having been used to control heating and cooling circuits with large process delay time.
What is interesting at this project is the data integration of all technologies (SMA PV inverters, Studer accumulator control, Xantrex inverter, Hogen hydrogen generator, and Fronius fuel cell). It makes possible to monitor and store all operational and diagnostic data from the technologies, and control them over a bus at the same time.