'Ai caduti dell'Adamello' plant for stationary energy generation through the use of Hydrogen as energy carrier
The plant for the stationary generation of electric energy through the use of hydrogen as energy carrier is installed at the refuge "Ai caduti dell'Adamello" located at an altitude of over 3000 m. The innovative aspect is to be found in the integration of some recently developed equipments never tested in such particularly crucial conditions. In fact, the temperatures of the working plant and its pressure have to be considered lower than those occuring in standard conditions.
Therefore, the realization of such a plant aims at carring out an high-flying experimentation of the equipments and finally, in a far future, at creating the basis to reach the energy independence from the other energy sources, already present in the structure referred above (gas oil plant), in case of not particularly hard energy requirements.
The plant has been completely integrated into the system for the energy production previuosly installed to supply the refuge (photovoltaic system with storage through a battery bench, solar-thermal collectors and generators).
Therefore, according to the energy need of the building, energy is generated without changing the current energy balance. In fact, the hydrogen production is performed only when an energy surplus of the photovoltaic production occurs; moreover, the gas oil group is never employed for the start-up of the electrolyzer.
The planning of the plant has been carried out on the basis of the pre-existing electric scheme; the layout of the plant is illustrated here below:
In particular, the plant is composed by a photovoltaic field of 12 kWp placed on the roof of the building, connected to an inverter (SMA). This latter is connected to the grid that is generated by a diesel engine and connected to a battery accumulators bench through an inverter.
The electrical generator working with fuel cells (based on the PEM technology) of 5 kWel has been installed in parallel respect to the batteries bench, and it is supplied by the hydrogen obtained on-site through an electrolytic dissociator of 2 Nm3/h and stored inside two tanks with a useful volume of 1 m3 each.
The electrolyzer represents the ideal solution for the hydrogen generation from renewable sources. In fact, the machine is able to produce highly pure hydrogen at a pressure of 30 bar fully independently from the primary electric source. Moreover, the output pressure allows the direct storage of the gas inside the tank without the previous use of a compressor.
The control system has been developed by El.Ma. for the supervision (on-site and in remote mode through an encrypted VPN) of every component of the plant through the single corresponding PLC included in every machine.
It sends the commands, controls the parameters according to the mode chosen for the whole system (equipment for the hydrogen production, hydrogen employment, supervision of the fuel cell generators, control and integrated management of the security systems). In addition, it allows the monitoring of the photovoltaic inverters, of the battery charge and the energy generation of the solar panels and the diesel generator.
The automated control, like the CN developed by El.Ma., is very important for the plant management: in fact, the optimization of the system can be obtained only through a continuous management of the power flows of the grid, and this is possible using a common communication language among the systems.
The integration of the several subsystems into a unique correctly functioning hybrid system depends on the complexity of the peripheral devices and it is as much as the size of the plant.
The use of a control system in remote that is able to query the several working machines in the plant represents the only solution for plants located in hardly accessible areas for which the maintenance and testing time have to be optimized and reduced as much as possible.