|● Wastes and energy crops|
Natural energy flows and sources such as sunlight, the winds, waves and tides, offer a relatively clean, safe and above all sustainable source of power. This chapter explores the renewable energy options, looking at the basic technology and at some current developments, and then reviews the overall global resource potential of renewable energy. In the following chapter we review renewable energy developments around the world.
Renewable energy technology
Renewable energy is so called because it relies on natural energy flows and sources in the environment, which, since they are continuously replenished, will never be exhausted. So they meet our first criteria for sustainability. In what follows, to provide a context, we first look at the basic technology before moving on in the next chapter to look at developments around the world.
The basic technology is very varied, reflecting the variety of natural energy sources. As has been indicated, most sources of renewable energy are the result, directly or indirectly, of the impact of solar radiation on the planetary ecosystem - the exceptions being tidal energy flows and geothermal heat. Incoming solar radiation provides energy for plant and animal life and drives the hydrological weather cycle - evaporating sea water and creating rain, which feeds into rivers and streams. Local