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The work concerns the optimisation of hydrogen production by electrolysis using renewable energy resources. To achieve this aim, the techno-economic analysis was dedicated to a system composed of PV panels and an electrolyser, including all associated technology such as the chopper circuit 1 . The first step was to complete a LabVIEW simulation program which was able to reproduce a photovoltaic (PV) plant connected to the alkaline electrolyser. The virtual instrument was developed on the basis of the models of incident radiation, PV cells and electrolyser. After the indication of PV cell type and number, tilt of all panels, number of strings 2 , latitude and main characteristics of the electrolyser (e.g. nominal power, number of electrolytic cells, working temperature and pressure), the program computes the hydrogen produced, the electrolyser running hours and other data, for a chosen period of the year. Differently tilted photovoltaic panels were considered either directly coupled with the electrolyser or connected via a DC converter between the two systems. The simulation program, called “RenHydrogen”, provides a qualitative calculation of the hydrogen production during the whole year, comparing different technological options and leading to the techno-economic optimisation of the PV-electrolysis system.

The purpose of this study is to evaluate on a real urban driving cycle the performance of a plug-in hybrid-electric vehicle, which is part of a series of pre-marketing vehicles, taking into account the real driving conditions. For this purpose have been considered the driving style influence, the traffic level, the path slope and the comfort level requested inside the vehicle by the driver. In particular the influence of auxiliary systems consumption on the total consumption of the vehicle has been evaluated. Attention has been paid to assess the effect of auxiliary systems consumption on the autonomy of the vehicle on electric mode. The data were collected under real driving cycles in the city of Rome. The importance and innovation of this work consist of two principal concepts: (i) the auxiliary systems consumption and its influences on total consumption and (ii) the acquisition analysis under real driving cycle. Different drivers were involved during the acquisition campaign along several itineraries characterized by the features of a real urban cycle (length, slope, traffic light posts, etc.). The data acquisition was carried out on-board in real time using a measurement chain which included: OBDII (On - Board Diagnostic systems - second version), hardware, laptops and software. Acquired parameters were: traveled distance, speed, air flow, equivalence ratio, RPM, voltage, SOC (State Of Charge) of the batteries. The calculated variables from acquired data were: fuel consumption, consumption and incidence of auxiliaries on the autonomy in electric drive.