At present, Hong Kong's electrical power, and our gas supplies, come from fossil fuels which have to be imported such as coal and oil. Fossil fuels are nonrenewable, that is, they are gone forever and can never be replaced after burning. Besides, burning fossil fuels creates pollution, and this in turn has adverse effect in the complex control mechanisms which regulate the earth's climate. In contrast, renewable energy resources - such as solar, wind, geothermal, biomass and ocean energy - are constantly replenished and will never run out. They are regarded as the everlasting utilizing energy resources. Most renewable energy comes either directly or indirectly from the sun. Renewable energy is a clean source of energy which will avoid damage to global environment due to the use of fossil fuels.