Elsevier

Renewable Energy

Volume 27, Issue 1, September 2002, Pages 1-12
Renewable Energy

Investigation on wind power potential on Hong Kong islands—an analysis of wind power and wind turbine characteristics

https://doi.org/10.1016/S0960-1481(01)00164-1Get rights and content

Abstract

This paper discusses the potential for electricity generation on Hong Kong islands through an analysis of the local weather data and typical wind turbine characteristics. An optimum wind speed, uop, is proposed to choose an optimal type of wind turbine for different weather conditions. A simulation model has been established to describe the characteristics of a particular wind turbine. A case study investigation allows wind speed and wind power density to be obtained using different hub heights, and the annual power generated by the wind turbine to be simulated. The wind turbine's capacity factor, being the ratio of actual annual power generation to the rated annual power generation, is shown to be 0.353, with the capacity factor in October as high as 0.50. The simulation shows the potential for wind power generation on the islands surrounding Hong Kong.

Introduction

Potential applications of renewable energy have been on the Hong Kong government's working agenda in recent years. Wind power is one of the potential renewable energy resources for this location, due to the strong winds on the islands surrounding Hong Kong Island and the Kowloon Peninsula. Taking Waglan Island as an example, the average annual wind speed is 6.92 m/s at 26.3 m above ground level, 82 m above sea level, as obtained from the weather data recorded by the Hong Kong Observatory. A mean wind speed such as this is very high for wind power applications [1].

As shown in Fig. 1, Hong Kong is characterized by a long coastline and numerous islands for such a relatively small territory, and provides opportunities for wind power applications. However, the potential for wind power has been somewhat neglected and no large-scale wind farms have been built. Research on wind power generation under Hong Kong's weather conditions has been limited. For one site at the Lantau Island, Fung [2] did a preliminary study on wind power using one-year measured data. Li [3] investigated the potential and the feasibility of offshore wind energy for Hong Kong using 1998 wind data. More research work is necessary to investigate the issues related to wind power generation to uniform local policy makers before wind power can be considered for large-scale application. This paper assesses the potential of wind power generation through a case study.

Studies have predicted wind power potential for different regions using the probability distribution method. Mulugetta and Drake [4] assessed the wind energy resources in Ethiopia by calculating the wind energy density. Rosen et al. [5] provided a detailed wind assessment for two sites for the windy southern port city of Aseb, Eritrea. In these studies, the capacity factors were calculated based on the chosen wind turbine. In this paper, not only the yearly but also the monthly wind speed probability density and wind power density (for different ground levels) are calculated to assess the wind power potential for Hong Kong islands. The results of the wind speed distribution and wind power density are related to the preferred heights, so that the height, being one important factor, must be established, but which is neglected in most studies. Here, the power generated by a particular wind turbine and its capacity factors are investigated for different hub heights.

Section snippets

Probability density function

There are several density functions that can be used to describe the wind speed frequency curve. Here, the Weibull distribution is used to describe the wind speed distribution. The wind speed probability density function (pdf) can be described as [6]:f(v)=kcvck−1expvck(k>0,v>0,c>1)where c is the scale parameter, unit of speed; k is the shape parameter; v is wind speed.

Once the mean and variance of the wind speed are known, the following approximation can be used to calculate the Weibull

A case study for wind power potential analysis

Waglan Island is chosen for the case study. As shown in Fig. 1, Waglan Island is located on the southeast of the territory with no surrounding mountains. A meteorological data recording station is located on the island and operated by the Hong Kong Observatory. In this paper the recorded data from 1989 to 1995 is used for analysis.

Analysis of wind turbine characteristics

To analyze the effect of the wind turbine's height on the wind power generation, a wind turbine of 10 kW with a DC generator is chosen for this case study based on the calculated optimum wind speed uop (11.08 m/s from Eq. (7)). The rated electrical power of the turbine is 9.7 kW (at rated wind speed 10.5 m/s), and there are four options for the tower height: 18.3 m, 25 m, 30.5 m, and 37 m. For these heights (additionally, 10 m, 15 m and 26.3 m are chosen for comparison), the wind power density

Conclusions

The proposed simulation model is found applicable for assessing the potential of wind power generation at a location. From the case study, it is found that the hub height of a wind turbine is an important parameter in power generation. When the hub height is 37 m, the wind turbine can operate for 6820 hours (77.85%) in a year, and can generate 32,400 kWh of electrical energy with a capacity factor 0.387 for Waglan Island.

With its above average yearly wind speed and wind speed probability,

References (13)

There are more references available in the full text version of this article.

Cited by (252)

View all citing articles on Scopus
View full text