Frequency Asked Questions

  1. What is the difference between renewable energy and sustainable energy?
  2. What is the difference between renewable energy and clean energy?
  3. Which renewable energy resources have potentials for exploitation in Hong Kong?
  4. What is the target for the use of renewable energy in Hong Kong?
  5. Can renewable energy replace a major portion of conventional power generation in Hong Kong?
  6. Is the cost of electricity of renewable energy power generation comparable to conventional power generation?
  7. Renewable energy resources such as solar energy and wind energy are often fluctuating and intermittent. Are they unreliable sources of energy?
  8. The manufacturing of renewable energy equipment consumes energy. Can renewable energy equipment produce enough energy to cover the energy used for its production?
1) What is the difference between renewable energy and sustainable energy?
Ans: Sustainable energy sources are energy sources which are not expected to be depleted in a timeframe relevant to the human race. Sustainable energy sources therefore include renewable energy sources and nuclear power, even though there is controversy over whether or not the latter should be regarded as sustainable for social and political reasons.
   
2) What is the difference between renewable energy and clean energy?
Ans: Renewable energy also falls into the category of clean energy. Although there is no universal definition of clean energy, clean energy may include natural gas and other clean energy supply options like highly efficient combined heat and power, and energy efficiency. Green energy, on the other hand, often means the same as renewable energy.
   
3) Which renewable energy resources have potentials for exploitation in Hong Kong?
Ans: According to EMSD's Study on the Potential Applications of Renewable Energy in Hong Kong, solar energy, wind energy, and energy-from-waste have potentials for exploitation in Hong Kong. It should be noted that there are constraints on the exploitation of these renewable energy resources, such as land constraints as well as cost and public acceptance issues.
   
4) What is the target for the use of renewable energy in Hong Kong?
Ans: The target for the use of renewable energy for Hong Kong is to have between 1 and 2% of Hong Kong's total electricity supply met by power generated from renewable sources by the year 2012, with this target being subject to regular review in the light of advances in technological solutions and emerging sustainability considerations.
   
5) Can renewable energy replace a major portion of conventional power generation in Hong Kong?
Ans: Due to the lack of large-scale renewable resources like hydro and geothermal, and due to land constraints for the exploitation of solar energy and wind energy, there are limitations to the large-scale exploitation of renewable energy in Hong Kong.
   
6) Is the cost of electricity of renewable energy power generation comparable to conventional power generation?
Ans: For places with good renewable energy resources, the cost of electricity of hydro, geothermal and wind power generation are comparable to conventional power generation. At the present moment, the cost of electricity from solar photovoltaic power generation is still higher than that of conventional power generation. However, such kind of comparison is not altogether fair to solar energy, because the "environmental externality costs" of conventional power generation has not been taken into account.
   
7) Renewable energy resources such as solar energy and wind energy are often fluctuating and intermittent. Are they unreliable sources of energy?
Ans: Solar energy and wind energy are intermittent in nature. However, solar energy and wind energy can serve as a reliable source of power when energy storage devices such as batteries are used to store up the energy. Alternatively, solar or wind energy systems can operate in a grid-connected manner, with the grid serving to supplement the fluctuations in the output of such systems.
   
8) The manufacturing of renewable energy equipment consumes energy. Can renewable energy equipment produce enough energy to cover the energy used for its production?
Ans: Renewable energy equipment like photovoltaic panels and wind turbines usually has a service life of over 20 years. During their lifetime, they can produce an amount of energy much greater than that needed to cover the energy used for their production. Take polycrystalline PV module as an example, according to a report (This web page has hyperlinks which may transfer you to third-party website.http://www.pvresources.com/PVSystems/Trackers.aspx) by the Department of Science, Technology and Society of the Utrecht University in the Netherlands, the energy pay-back period of a frameless module is estimated to be between 1.3 years to 4.6 years under normal Dutch insolation conditions.
   
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