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 * || ** The Use of Renewable Energy in Hong Kong (2003/09/15) **|| What is renewable energy and why use it ?

Most energy resources in the world are derived from fossil fuels (coal, oil, and natural gas) which lead to Greenhouse Gas (GHG) emissions (including carbon dioxide, methane, nitrous oxide) and other air pollutants, resulting in global climate change (Fig.1) as well as local or regional air pollution. Fossil energy is not renewable, drawing on finite resources that will eventually dwindle. In contrast, renewable energy resources- such as solar and wind energy- are clean sources of energy with much lower environmental impacts, and they are constantly replenished and will never run out. Hydro, biomass, geothermal and ocean energy are other forms of renewable energy.

A rise in energy demand has exacerbated the global warming and pollution impacts. Global actions are being taken to limit carbon dioxide and other pollutant emissions. In view of the threat to the well being of humans, it is apparent that renewable energy should be widely encouraged through appropriate technologies, at the same time drawing attention to social responsibility of all.

The world trend.

The U.S. Department of Energy projects moderate growth in the world’s consumption of hydroelectricity and other renewable energy resources over the next 24 years (Fig.2). The consumption of renewable energy worldwide is projected to grow by 56 percent, from 2001 to 2025. Much of the projected growth is expected to result from the completion of large hydroelectric facilities in developing countries, particularly in developing Asia, and with regard to China’s Three Gorges Dam hydropower project. Among the other (nonhydroelectric) renewable energy sources, wind power has been the fastest growing in recent years. In Western Europe, Germany, Denmark and other nations have installed a significant amount of new wind power capacity. However, it is recognized that in the absence of significant government policies aimed at reducing the impacts of fossil fuel energy sources on the environment, it will be difficult to extend the use of renewables on a large scale.

Use of renewable energy in Hong Kong

Hydropower, traditional biomass energy and geothermal energy are obviously not feasible in Hong Kong. The renewable energy identified as having the potential of wide application in Hong Kong are:

· Solar Energy: Hong Kong has abundant sunlight. Solar panels collect sufficient energy from the sun and transform it into electrical power. The systems can be:

o Solar thermal systems (solar water heating and absorption air-conditioning). It has been estimated that some 2,500 square metres of solar collector panels are in use for water heating in government properties and new projects, OR

o Photovoltaic systems to generate electricity.

· Wind Energy

Solar energy

The use of solar energy, though still limited, has been providing hot water for a number of types of premises while some small scale photovoltaic systems have been installed in remote areas to generate electrical power to operate lighting and on-site data recording equipment.

An early project in Hong Kong was a Solar Hot Water Plant (Fig.3) completed in 1978 in a hotel complex in Tsim Sha Tsui, where solar energy was used to supplment the heating requirement of the domestic hot water system(3). In the 1980s, the government had started installing solar panels in various projects. Installations were completed in 1983 in a drug addiction treatment centre on the remote island of Hei Ling Chau, and in the Shek Pik prison on the Lantau Island.

In 1994 a solar water plant (Fig.4) was completed to serve the hydrotherapy pool in the Tuen Mun Hospital. The plant also acts as a supplement to the steam heating system(3).

Solar panels is one of the three sources for pool heating in the Shing Mun Valley Swimming Pool Complex(3). It was completed in 1998. In another project completed in 1999, 450 solar panels were installed to provide hot water for processes in the new slaughterhouse in Sheung Shui.

In Hong Kong waters the Marine Department has used solar energy to power about 90% of the major battery-operated navigation aids(4) of lighted buoys and lighted beacons. Refuelling costs are reduced as a result.

In the Victoria Park Improvement Project under phased construction, pole-top lantern and ventilation fan, driven by the electricity generated from solar panels, were installed in 2001.

Hong Kong's largest solar electricity generation system which is a Building Integrated Photovoltaic (BIPV) system(5), was installed in January 2003 atop the Wan Chai Tower as a 12-month pilot project. The electricity from the panels will meet part of the electrical energy demands of the building. The BIPV panel is an innovative concept that integrates the solar panel system within the building fabrics such as façades or sunshades. Recent examples include the Hong Kong Science Park Building and the Primary School in Ma Wan. Besides the application of the BIPV system, the Science Park Building also has the first "fuel cell" scheme implemented in Hong Kong.

The Hong Kong Observatory has been involved in renewable energy for nearly 20 years. Since the 1980s the Observatory has employed solar cells to power some automatic weather stations. Up to now, there are over 20 stations equipped with solar cells.

The private sector was also taking up the challenge with an increasing number of studies on the application of photovoltaic and wind generation technologies. Examples of application include the use of photovoltaic cells to power mechanical parts of buildings, like louvres of facades. Similar photovoltaic cells in the Breakthrough Youth Village are used for a water heating system.

Wind energy

Hong Kong's first wind/solar hybrid system was installed at the Shek Kwu Chau Drug Rehabilitation Centre.

Starting from 2000, wind power is also utilized at some Hong Kong Observatory automatic weather stations in remote areas or islands which have hitherto been relying on solar power as a source of energy. However, inadequate sunshine means that occasionally there may be insufficient power to keep the stations running. To provide an alternative energy source, wind-powered generators have been deployed at some stations since 2000. As of today, such generators have been deployed at eight automatic stations at Lantau and in islands near the Chek Lap Kok airport.

Friends of the Earth (Hong Kong) has performed a wind resource assessment project on both Lamma and Po Toi Islands and has suggested that importing wind energy from Guangdong is commercially and technically viable.

Problems and development

As the demand for heating energy is relatively low in local buildings, the economic advantage of using solar heat is undermined. On the other hand, the high-rise and high-density urban environment of Hong Kong create difficulties to solar energy applications as it may be difficult to find suitable open space for solar collectors and equipment, except for rural areas. Solar Equipment also have to be firmly anchored on the roof to withstand high winds which sometimes prevail in Hong Kong. This adds costs to solar installations.

The proposed targets for local renewable energy sources, as contained in the government consultancy report (Potential Application of Renewable Energy in Hong Kong, commissioned in 2000) are less than 2% by 2012, to 4.32% by 2022. These figures are considered too modest by environmental groups as compared with developments in Asian countries, the European Union or China. A minimum of 5% renewable energy has been suggested to be mandated in Hong Kong's energy mix as soon as market barriers are removed. Such internal market impediments are believed to have held back development of wind and other forms of renewable energy. __________________________________________________________________________________ (1) http://www.giss.nasa.gov/research/observe/surftemp/ (2) http://www.eia.doe.gov/oiaf/ieo/hydro.html (3) http://arch.hku.hk/teaching/cases/regent/regent.html (4) http://www.mardep.gov.hk/en/pub_services/ocean/atn.html (5) http://www.archsd.gov.hk/english/reports/ envreport_2002/eng/14.html || || []