These are energies obtained from natural sources that are continually renewed and are inexhaustible, although intermittent. Technological development (production and storage technologies) will contribute to their competitiveness and, mainly, will provide greater efficiency and production capacity. These factors will be decisive for renewable energies to replace fossil-based energies.
Renewables, being clean and inexhaustible, have considerable limitation in terms of production to be able to satisfy all our energy needs, even more so in a highly industrialised society. Except for geothermal energy, they depend on the weather: wind power if the wind is blowing, solar power during the day when the sun is shining, and not at night, and sometimes the times of greater demand do not coincide with the most intensive production periods. Some technologies like wind power have achieved considerable technological maturity, and the installed capacity of renewable energy is increasing worldwide thanks to this factor. Even so, several projects for the installation of wind farms in Euskadi have been put on hold as a result of protests from citizens.
All these difficulties will be overcome as time goes by, thanks to research and technological development, but they are setbacks that we need to be aware of if we really want to know where the limits of renewable energies lie.