Renewable energy techniques

There are a number of renewable energy sources:

- Wave Power
- Solar Power
- Hydro Power
- Wind Power

Wave Power

Wave power is generated from ocean waves or tides. Waves are formed when wind blows across a large body of water. The potential for waves to supply energy is enormous. The amount of power a wave can produce is related to its height and average speed. The distribution of wave energy around the world is closely linked to wind strength - where winds are strongest the wave potential is greatest. Wave power as a commercial energy source is still very much in the experimental stages. However, tide powered paddle wheels were used in Egypt as far back as 1100 AD, and in 1909, the California Wave Power Company used wave energy to produce electricity to power light lamps on wharves.

Solar Power

The rays emitted by the sun sustain life itself, and provide not only sunlight, warmth and allow plants to grow, but is already widely used for heating of water, heating and cooling of buildings, some low temperature industrial applications and solar thermal power systems.

Solar cells (Photovoltaic cells or P.V.'s) convert sunlight directly into electricity. They were developed in the 1880's but efficiency was poor. It was not until the 1950's that the efficiency was improved to a point where they became a viable source of energy. Now, Solar cells have become a popular way to generate electricity, particularly in remote areas.

Hydro Power

The use of water to produce power goes back as early as 300 BC when water wheels were used in Greece. Hydro electricity was first produced in 1882 and by the turn of the century the technology was being used all over the world. Hydroelectric power is based on the simple principle of using falling water to spin a shaft connected to an electric generator. The greater the fall of water, the greater the power to spin the shaft. The greater the quantity of water, the greater the number of shafts that can be used to drive generators.

Hydro electricity uses no fossil fuels in the generation process and no chemical, air or water pollution is formed. However, it usually requires a dam to be built. The production of electricity using water is clean and efficient.

Wind Power

Wind power has been used for over 5000 years as an energy source for sailing ships, pumping water and grinding grain. In more recent times it has become a commercially viable method of producing electricity, with wind farms throughout Europe and the USA.