Christophe Darras

Investigation on photovoltaic/hydrogen hybrid system for an isolated electrical grid

The object of the study is to reduce the daily load peaks on an insular electric network (corsica island, france) using with help to renewable energy systems. the methodology is based on an energy balance between a pv array, an electrolyzer and fuel cells (50 kw) supplying a seasonal load profile built from electrical network load peaks. this load is supplied firstly by the pv array and the fuel cell produces complementary power when the pv system is deficient. an electrolyzer, using unconsumed pv energy produces hydrogen for the fuel cell. in the present work, at the beginning of the operation, the hydrogen stock is sufficient to satisfy a given number of days corresponding to the system autonomy (loss of load probability = 0). solar and ambient temperature data were measured at our laboratory weather station in ajaccio (41°55′ n, 8°48′ e, 70 m altitude). hourly data are available for the years 1998 to 2004. the originality of this approach was to determine a whole methodology allowing to obtain quickly sizing curves for a pv/h2 hybrid system supplying a given load (remote sites and/or grid connection).

Modeling and Simulating of an Energetic Complex System Constituted by a Photovoltaic Array, a Wind Turbine, an Electrolyzer and Fuel Cells

This paper models an hybrid system for providing a typical electrical load for a family. The system consists of a photovoltaic (PV) array, a wind turbine (WT), and a fuel cell. The fuel cell produces complementary power and is able to satisfy the load. An electrolyzer, using PV or WT energy not consumed by the load, produces hydrogen for the fuel cell. At the beginning of operation, the hydrogen stock is sufficient to satisfy a given number of days of autonomous operation. The data used are the typical hourly load, the hourly solar radiation in the plane of the PV array, and a local meteorological station estimate of the hourly wind speed averaged over 18 years. The objective was to optimize the system, in terms of power for each component.