G. Graditi

A regenerative hybrid PV-PEMFC low power system is a suitable solution to replace batteries and to supply small electric devices placed in remote areas with no grid connection. Such a system was designed and built including a PV array, electrolyzer, PEMFC stack (6We) and hydrogen storage tank. As well known a hybrid PV-PEMFC energy system may represent a reliable solution to the renewable energy storage problem. Hydrogen produced by such a system is a clean fuel, suitable to replace traditional fuels which contain carbon damaging the environment. The paper reports results of a preliminary, non-dynamic experimental analysis performed on the system in order to study the effects of the anode pressure and external temperature on performance. A miniaturized system represents also a safe and unexpensive solution to perform analysis and simulate larger PEMFC applications. Several auxiliary devices were employed in order to obtain a system suitable for indoor and outdoor analysis. This study proposes also a simple semi-empirical mathematical model based on a graphic analysis and a non-linear regression of experimental data sets, for specific operating conditions, processes and materials employed.

The aim of the paper is to evaluate the technical feasibility and aspects related to the use, in an uninterruptible power supply (UPS), of fuel cells instead of traditional electrochemical batteries. The proposed system, named UPS-FCB (fuel cell based) presents a modular and versatile system configuration; particularly it is possible to integrate it with traditional UPS. Moreover the system features can be modified in terms of power, reliability, back-up time, etc., by changing the power devices. A detailed experimental analysis has been carried out on a passive stand-by UPS integrated with a FCB; experimental results can be easily extended to the other possible system architectures.