Hydropower And Wind Potentials In Hong Kong Environmental Sciences Essay

For decades mankind are in search for new energy resources to deal with the depleting fossil fuel. A lot of renewable energy and associated technologies were developed to assist current energy use to mitigate the imperative energy crisis. The current issues of climate change and global warming accelerated the needs into researches on renewable technologies even more.

Hong Kong is a special city with limited energy resources in a densely populated space. Current energy source in Hong Kong mostly rely on imported fossil fuels. The intention of replacing fossil fuel with other alternatives have become clear in both Government and non- Government Organisations.

The Energy Efficiency Office (EEO); Electrical, Mechanical Service Department (EMSD), HKSARG has performed a study on feasibilities of various kinds of renewable energy in Hong Kong in 2001 (EMSD, 2001), the study gave an overview on feasibility of Solar, Wind, Fuel cells, Energy-from-Waste, and some other alternative energy. Every technologies was analysed, giving a conclusion that solar will be the most viable renewable energy source.

The study of Tidal, and Hydroelectricity, however, was loosely studied due to the belief that they are relatively new technologies. However, although they are not being researched until very recent years, they have been used by human long beyond history. Mills that uses tidal energy has been found in the 12th century (Wallechinsky), whereas the hydro-energy was used even further back to Ancient Greek and Roman, where they use hydro-power for grinding mills (The U.S. Department of Energy).

Bagcı carried out a research in 2008 targeted to study the potential of developing a zero energy region in outer Island. Peng Chau was analyzed with different implementations of renewable energy and it is shown that a combination of solar, wind and hydro energy were a possible solution towards an Island that is independent from fossil fuel energy supply (Bagcı, 2009).

Despite the researches above, there is little research on full scale analysis on the feasibility of Hydro and Tidal energy in Hong Kong. Therefore it is of interest to determine whether the advances of technologies have gain points for Tidal and Hydro energy as potential alternative energy sources in Hong Kong.

Tidal Energy

Figure 1. Operating principle of Tidal Barrages (Palmer, 2008)

Tidal Energy is a result from gravitational force between celestial body such as the earth, moon, sun etc., as the moon is the nearest among other celestial body, it is usually considered as the only contributor to the tidal formation. The moon rotates around the earth every 27.3 days and the earth rotates along its axis every 24hr. The net effect is that tidal fluctuation occures twice each 24 hour 50 mins, same as the earth rotation period with respect to the earth-moon system (World Energy Council, 2004). The amplitude from such fluctuation is called the tidal range, and is the energy that can be captured through a turbo-generator in tide barrage to produce electricity (Figure 1). It is suggested that Tidal energy can provides 5 % of the electricity generated worldwide (Palmer, 2008).

According to the meteorological data provided by the Hong Kong Observatory (HKO), Hong Kong displays a gradual change in tidal characteristics, both in tidal range and tidal occurance of high and low tides travelling from southeast to the northwest across the territory. Within a tidal cycle, Waglan Island is the first to experience high tide and low tide whereas Tsim Bei Tsui is the last. Tsim Bei Tsui however, possess the largest mean tidal range of 1.4m, where Waglan Island and Victoria Habour generally possess a tidal range within 1m. (CEDD, 2002; HKO, 2009)

Hydro energy

Hydro energy shares the same energy carrier with Tidal energy, in which energy from water flow is captured with a marine turbine to generate electricity. It can be install anywhere as soon as water flow exists. Scales of Hydropower generator can be as large as constructions of dam to micro scales, usually found in small villages. Large scale generators were not considered to be implemented as no suitable sites were avaliable. In the report by EMSD, Hydro-energy were briefly analysed, and it is shown that potential of hydro-power in Hong Kong is relatively low compared to wind and solar energy (EMSD, 2001).

Despite the feasilbility of Hydroelectricity dam in Hong Kong, there is a debate on the emission of greenhouse gas via this technology. A few studies had suggested that hydroelectric dam will generate three times more than fossil fuel plant to generate the same amount of electricity, in which plants died underneath an operating dam possess anaerobic digestion, generating a significant amount of GHG, especially in south America tropical (e.g. Brazil, Argentina) where hydroelectricity dam is the main source of renewable energy supply. Therefore the “cleanness” of Hydropower is back in a debate (Graham-Rowe, 2005).

Wind energy

Wind energy is so well known and well developed that it is seen as the major potential renewable energy source that are viable in Hong Kong. Turbine were driven by wind to produce energy, scale of wind turbine are ranging from 198m high turbine generating 6 MW of electricity to some 2kW in micro size wind turbine. EMSD also analysed the potential sites for the installation of wind turbine, which a wind map was introduced for references by the public (Figure 2). Local applications include the famous 800kW wind turbine installed in Lamma Island, as well as the proposed wind farm in South-eastern Waters (EPD, 2006).

Project Description

This Project was targeted to review and anaylse the potential of Tidal and Hydro energy, and to compare them to the well developed Wind energy in Hong Kong. Since such energy sources are largely depend on meteorology, it is necessary to analyse as well as meteorological condition to determine which energy source are most suitable in Hong Kong. Moreover it is useful to review on current development of mentioned technologies to provide example for the implementation in Hong Kong.

Objectives

This project aims to:

Give an overview of current energy consumption patterns in Hong Kong

Provide an update on researches on Tidal, Hydro and Wind energy, these include

Technologies involved and their latest development

Overseas examples of application

Potential strategy of implementation in Hong Kong

Compare each of energy source to analyse their potential in Hong Kong, these include

Meteorological assessment and potential energy gain

Environmental Impact Assessment

Cost Effectiveness / Costing

Figure 2. Wind Power Density over the Region of Hong Kong (EMSD, 2001)

Scope of Work

To determine whether the technologies are competent in mitigation energy crisis in Hong Kong, it is always easier to understand how the locals use their energy, as well as the energy consumption in Hong Kong. Therefore it is reasonable to give a brief overview on energy flow pattern in Hong Kong. Energy source distribution, energy usage by different users can be obtained from the EEO, EMSD.

Since Wind energy was well researched and there are a lot of applications in Hong Kong, wind energy will be used as a base for comparison with other technologies encountered in this project. Local and overseas examples will be discussed, as it provides a real life example into the application of such technologies.

As mentioned before this project requires a significant amount of meteorological data, therefore meteorological observations from the Hong Kong Observatory (HKO) will be analysed to review the possibilities of implementing tidal, hydro and wind energy. Despite the HKO, observations from the Environmental Central Facilities can also available to the public for detail analysis of wind and tidal observations. (Environmental Central Facility)

Lastly, if viable, a cost analysis on some of the technologies can be carry out to demonstrate the economy of such renewable technologies and thus cost effectiveness can be use as an indicator to compare the aforementioned technologies.

Time Management

This project is mostly a Literature Research Project with some analysis on meteorological observations. Major milestone includes:

31 January, 2010; submission of inception report

30 September, 2010; submission of preliminary findings

21 April, 2011; submission of project title and draft dissertation (tentative), and expression of intention to complete project

30 June, 2011; Oral Presentation (tentative)

8 August, 2011; submission of final dissertation (tentative)

Appendix A shows a Gantt chart showing tentative schedule of the project, stating the milestones as well as phases of the project.