Other Renewable Energy Sources

Wave power, tidal power, municipal solid waste, gas from animal wastes (biogas), landfill, peat energy and ocean thermal energy conversion (OTEC) are the other renewable energy sources (RES). Water energy sources are hydropower, tidal and wave technologies. 

The ocean thermal energy conversion (OTEC) is an energy technology that converts solar radiation to electric power. OTEC systems use the ocean s natural thermal gradient to drive a power-prodncing cycle. As long as the temperature between the warm strrface water and the cold deep water differs by about 20 K, an OTEC system can produce a significant amormt of power. The oceans are thus a vast renewable resomce, with the potential to help tts produce billions of watts of electric power. 

Biogas can be obtained from digesting the organic material of municipal solid wastes (MSW). The composition of MSW varies by the somce of waste however, in all cases the major constituents of MSW are organic in nature and the organics accoimts for more than 50% of MSW. The economic exploitation of methane is worthwhile after one year from the start of the landfill operation. 

Methods developed for treatment of landfill leachates can be classified as physical, chemical and biological, which are usually used in combinations in order to improve the treatment efficiency. Biological treatment methods used for the leachate treatment can be classified as aerobic, anaerobic and anoxic processes which are 

---

Biomass-derived energy, together with other renewable energy sources, is expected to cover an increasing amount of our energy consumption. 

However, we must remember that solar, wind, and most other renewable energy sources are intermittent and regional. They can only become major power sources if we find a way to store and transport their energy efficiently. 

Hydrogen is universally available in the form of water from which it may be extracted electrochemically using electricity derived from nuclear, hydro or other renewable energy sources. 

---