The increasing interest in renewable energy sources originates from the negative impacts of overexploitation and the use of fossil fuels with their damaging influence on climate change. Besides, the continuous population growth requires higher energy provision or related energy services (e.g., heated living spaces, electricity, information, mobility) with increasing environmental impacts. Consequently, the “energy supply problem” in conjunction with the underlying “environmental problem” is a major topic in resource assessment, technology development, as well as in the energy and environmental worldwide policies.
Renewable energies originate in the movement and gravitation of the planet (i.e., tidal energy, wind energy), heat stored and released by the Earth (i.e., geothermal energy), and in particular energy radiated by the Sun (i.e., solar radiation). The main renewable energy sources, without the consideration of heating systems, are presented in this chapter. The resource estimation available from different sources as well as the measurement and resource assessment techniques is illustrated.
The main renewable sources are classified and characterized in a particular location, describing the renewable energy flows and considering the spatial and time variations. The focus is on the principal variables that need to be known for the hybrid renewable energy systems design and project development.