"Renewable Energy Sources and Hydrogen" (Section I - Chapter 4).

This volume is aimed at providing a general overview on the current status of the research activities and their future trends, opening this work with scenarios focused on the main scientific areas of the CNR-DET. As it is well-known, the energy and transport sectors play a crucial role in the development of our civilization. They impact decisively both on economic development and on problems involving the whole planet, such as climate changes and the pollution of large urban conglomerates, in which more than 60% of the world population will be living by the end of the present century. Estimates on the evolution of world energy consumption (conform to the peak oil theory) forecast that hydrocarbon consumption will reach a maximum level over the next ten years and, then, it will decrease. The analysts agree in predicting an increase in the use of coal, to meet the demand of emerging economies (in particular China and India). However, as fossil fuels start declining, it is expected a lack in energy production capacity that probably will be possible to fill with nuclear fusion. The lesson to be drawn from these scenarios is that it is necessary to slow down the demand for energy as much as possible, through the massive use of energy-saving technologies, in order to gain time to find solutions that are not available today.