What is Renewable Energy

The term "renewable energy" may be defined in several ways, and there is not at present a universally accepted definition. Generally speaking, renewable energy sources are secure and inexhaustible, in the sense that there is no problem of reserves being depleted.

Major types of renewable energy sources (or renewable resources, renewable energies, renewables) include:

  • Solar energy
  • Wind energy
  • Biomass energy
  • Hydro energy
  • Geothermal energy
  • Ocean energy

Other than geothermal and tidal energy (a form of ocean energy), most of the renewable resources are ultimately derived from the enormous power of the sun's radiation. Solar energy is solar radiation by itself. Wind energy and hydro energy are caused by heating of the atmosphere and the oceans by solar radiation. Biomass in the form of plants store energy through the process of photosynthesis. Some forms of ocean energy (such as wave energy) can also be traced back to solar radiation.

This website focuses on "renewable energy technologies" with potential for application in Hong Kong. Relatively less emphasis is placed on those technologies with minimal potential for application in Hong Kong. Renewable energy technologies covered by this website are grouped under the following headings:

  • Solar
    • Solar water heating
    • Solar photovoltaic
    • Other solar technologies

  • Wind
    • Large wind turbine
    • Small wind turbine
    • Offshore wind farm

  • Waste-to-energy
    • Landfill gas
    • Anaerobic digestion
    • Thermal treatment

  • Other RE technologies
    • Biofuel
    • Ocean
    • Hydro power
    • Geothermal
    • Biomass combined-heat-and-power (CHP)

Waste-to-energy, liquid biofuel for transportation, and biomass CHP technologies are all related to biomass energy, even though put under different headings.

A pamphlet titled "Know More About Renewable Energy" is published by EMSD. Click here to download.

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