Renewable energies can be used to generate electricity and heat, as well as in the mobility sector. While wind and sun produce variable amounts of energy in the electricity sector depending on weather conditions, the availability of bioenergy, hydropower and geothermal power is nearly constant or can be stored and controlled. On the whole, this results in an ongoing energy supply that is reliable and tailored to demand.
Owing to their enormous range, from a few watts up to hundreds of megawatts, renewable energies can also be adapted to any kind of energy service. Closely meshed with modern energy technologies, they can make a considerable contribution to a secure energy supply, even in a modern industrial society.
Not every source of renewable energy can be put to commercial use in every country. Certain regions, for instance, have potentials for using solar power at a very low cost. The best potentials for using solar power are found in the world’s so-called sun belt (between 20 and 40 degrees of latitude in the Northern and Southern Hemispheres). The technical potential for wind energy is in turn dependent on the average wind velocity. This is generally much lower over continental land masses than over the oceans. Practically every country, however, has attractive locations for a wide variety of renewable energies.
The choice of a suitable technology or combination of technologies depends on conditions at the site as well as the respective requirements placed on the type and scope of energy provision. These include, among others:
Examples of criteria for choosing suitable renewable energy technologies.
|Local conditions||User requirements|
|Natural potentials (for example, solar radiation, wind speed, biomass availability)||Form(s) of energy: electricity, heating/ cooling, mobility|
|Political promotion schemes (for example, public investment grants)||Peak demand|
|Infrastructure (for example, grid connection)||Capacity/annual capacity|
|Funding for initial investment (equity or borrowed capital)||Fluctuation of the demand for energy in the course of the day/year|