The use of renewable energy sources for distributed power generation is the
most considered alternative to the use of fossil fuels in centralized power
plants. However, due to their discontinuous operation, the availability of
suitable energy storage systems is required. In this field, hydrogen storage
technologies are one of the most interesting options. Hydrogen production,
storage and utilization technologies have a high innovation content even if
several tecnical and economical problems remain to be solved.
In this framework, Sardegna Ricerche has promoted the realization of the
“Concentrating Solar and Hydrogen from Renewable Energy Sources”
Laboratory in collaboration with the University of Cagliari. Main mission of the
laboratory is implementation, testing and demonstration of the technologies
related to the production, storage and use of hydrogen from renewable energy
sources. For this reason, the main research activities are in the field of the
electrochemical characterization of fuel cell stacks and their materials with the
aim to improve performance in terms of durability and efficiency, as well as
the development of hydrogen storage systems. In particular, the laboratory
includes a stand-alone micro-grid powered exclusively by a photovoltaic array
and a wind turbine. The microgrid is also coupled with two different energy
storage systems: a battery bank and a hydrogen storage system. In particular,
the latter is based on two PEM electrolyzers (1 Nm3/h each), four hydrogen
storage tanks (1 m3 each) and a PEMFC fuel cell (5 kW).
The main aim of this paper is to carry out a detailed analysis of the expected
micro-grid performance. In particular, the focus was laid on the
implementation of a novel energy management system (EMS). The proposed
EMS defines the optimal generation scheduling of the two storage devices in
order to minimize operating costs and maximize the efficiency of the system.
The results of a comparative study with more conventional EMS demonstrate
that the proposed EMS leads to a decrease of almost 5-10% of the annual
operating costs and energy losses
