Fuel cells - the future of electricity generation for portable applications

Fossil fuels, including crude oil, coal and natural gas are currently the key resources for world energy supply. Hence, the majority of electrical energy production is realized via combustion of conventional fuels, such as: coal, methane and petroleum. However, increasing emissions of pollutants and greenhouse gases from fossil fuel-based electricity production (especially withrespect to SO2, NOx and CO2 discharge) bring about major environmental concerns. In addition, the status of conventional (fossil) fuel reserves is still uncertain. Thus, production of "clean" electrical energy, especially from renewable resources, such as: biomass, solar, photovoltaic, geothermal, hydro and wind energy sources becomes of significant importance to the world's economy. Fuel cells (FCs) are electrochemical cells, which convert a source fuel (e.g. H2, CH4, alcohols, etc.) into an electric current. They generate electricity inside a cell via electrochemical reactions between a fuel and an oxidant, in the presence of an electrolyte. In general, most of fuel cells can be operated as emission-free devices, based on fuels produced fromrenewable resources. With a variety of possible FC types, fuel cells could potentially serve in stationary, transportation or portable applications. This work is a review of the state-of-the-art in fuel cell technology, with respect to FC employment in portable applications.