As global natural resources depletion and concern on emission of greenhouse gases intensify, the interest for low emission technologies and the use of renewable energy increased in the world. In this context, this paper aims to present an hybrid energy system for on-grid micro residential and industrial applications. The system is composed of a micro combined heat and power (CHP) unit, including a natural gas (NG) reformer coupled with proton-exchange membrane fuel cell (PEMFC), solar photovoltaic modules (PV) and a bank of batteries (B), connected to the grid through a bidirectional inverter. Different system configurations (PEMFC + PV + B, PEMFC + B, PEMFC + PV), with or without cogeneration of the heat from the CHP system, were investigated to calculate the required NG and electricity flows and assess the economic cost during 10 years of operation in an 2020–2040 horizon. The impact of fuel cell sizing and two electricity tariffs was also assessed for both applications. Afterwards, the cash flow in terms of net present value of a 20 years operation period was simulated within the Brazilian context, yielding estimated paybacks between 7 and 19 years for the simulated cases. Finally, an environmental impact analysis was carried out to investigate the total GHG emissions for some cases of interest in this work. The proposed system could reduce total emissions up to 31% when compared to the complete power and thermal supply by the Brazilian Electricity grid and natural gas heater The results showed that the proposed system were economically viable, relatively low-polluting and more efficient than traditional PV systems.
