1
INTRODUCTION
The Castle Peak Power Company Limited (CAPCO), a joint venture between
CLP Power Hong Kong Limited (CLP Power) and ExxonMobil Energy Limited (EMEL), recognises
the Government of the Hong Kong Special Administrative Region (HKSARG)’s
efforts in exploring alternative power sources, including renewable energy, and
in promoting public awareness of these alternatives. To this end, CAPCO has launched a commercial
scale wind turbine pilot demonstration (hereafter referred to as wind turbine)
to:
·
collect
engineering and environmental information (including the necessary statutory
permitting requirements) required for potential development of wind power
generation in
·
investigate
the economic, environmental and technical feasibility and practicality of wind
energy application in
·
educate
and raise the
community’s awareness of the issues, costs, constraints, benefits, etc of wind
energy generation in
The project will take a grid-connected commercial scale wind turbine
through the full site selection and regulatory process so that the community
can gain more knowledge and experience about wind energy application in
A rigorous site selection process has been conducted to identify
suitable land based areas which have access to CLP Power’s transmission network
for the development of the wind turbine.
The potential areas were assessed with respect to wind resource, grid
interface; environmental, physical and social constraints. This Environmental Impact Assessment (EIA)
study is for the development of a commercial scale wind turbine pilot demonstration at Hei Ling Chau (hereafter referred to as the Project).
1.2
Objective and
Scope of the EIA
The Project is classified as a Designated Project by virtue of Item D.1
of Part I of Schedule 2 (ie public utility
electricity power plant) under the Environmental
Impact Assessment Ordinance (Cap. 499) (EIAO). The construction and operation of the wind
turbine pilot
demonstration at Hei Ling Chau will therefore
require an Environmental Permit.
The main objective of this EIA Study is to provide a detailed assessment
of the nature and extent of potential environmental impacts arising from the
construction and operation of the Project in relation to the issues specified
in the EIA Study Brief (No. ESB-145/2006),
including noise, ecology, landscape and visual, construction phase water
quality and waste management, and cultural heritage impacts.
The EIA was conducted in accordance with the guideline on assessment
methodologies provided in the Technical Memorandum on Environmental Impact
Assessment Process (EIAO-TM). The general approach for the assessment
included:
·
Description
of the baseline environmental conditions for the impact assessment;
·
Identification
of potential impacts;
·
Evaluation
of potential impacts; and
·
Recommendation
of mitigation measures and environmental and monitoring programme.
The assessments in this EIA Study are conducted using
well-proven and internationally accepted methods based on the worst-case
conditions associated with the construction and operation of the Project.
2
Project Description
The location and site arrangement of the Project are shown in Figures
2.1a and 2.1b, respectively. A brief description of the construction and
operation of the Project is provided in the following sections.
The proposed wind turbine will be a three-bladed horizontal axis machine
(Figure 2.1c illustrates a typical
three-bladed horizontal axis wind turbine).
The main electrical and mechanical parts, including the gearbox, the
generator with a rated capacity of between 800 kW and 1.3 MW and the yaw
mechanism, will be housed in the nacelle, which is located on top of a
tower. The tower will likely be a
tubular steel structure, but may be fabricated from other materials such as
concrete ([1]).
The tower will stand upon a concrete base with approximate dimensions of
9 m x 9 m.
Figure 2.1c A Typical 3-bladed Wind Turbine
The rotor blades capture the wind and transfer its power to the rotor hub,
which is connected to the electrical generator via the gearbox. The electrical power generated is transmitted
via a step-up transformer to a substation, from where the power is fed into the
nearest existing 11 kV power grid through overhead or underground transmission
cables (see Figure 2.1b).
2.2
Construction of
the Project
The major construction activities for the Project will include upgrading
of existing roads and creation of temporary access for the delivery of
construction materials and equipment, formation of the platform for the
erection of the tower, construction of the tower foundation, erection of the
tower, installation of the nacelle and rotor and installation of the control
and transmission systems.
Two access routes have been identified for the delivery of construction
materials and equipment to the Project Site (Figure 2.2a). The first route, the long access route, makes
use of the existing heavy load berthing facilities and road system. The route will take the northern part of the
existing loop route and follow the existing alignment to the Project Site. Minor enabling works will be required at a
few locations to facilitate vehicle passage.
The long access route will be used for the delivery of construction
plant items and materials.
Due to the size and weight of the wind turbine components, their
transportation using the long access route will require significant road
upgrading works (including major slope works) at many locations. An alternative route, the short access route,
will therefore be used to transport these components to the Project Site. The turbine components will be delivered by a
flat bed barge with an attendant crane and moored off-shore, adjacent to the
existing pier at the southern part of the island, within the typhoon
shelter. The barge will require a clear
water depth of 2m. A hydrographical
survey has been carried out in the area and confirmed that there is sufficient
water depth and hence no dredging will be required.
The short access route (see Figure 2.2a) will involve the
construction of a temporary steel platform at the existing jetty in the
south-western part of the island and temporary steel bridge structure. The temporary platform will be constructed
above the high tide level and no marine works will be required. The wind turbine components (including the blades,
nacelle, and steel tower sections) will be lifted from the barge to the
temporary steel platform using a floating crane. The components will be lifted to the deck of
the temporary bridge by the crawler crane and then transported by the
self-propelled transporter to the Project Site along
the existing road. Minor widening or
slope trimming may be required at certain locations of the short access route
to allow the passage of long vehicles (see Figures 2.2a).
The Project Site (see Figure 2.1b) will occupy an approximate
area of 54m x 100m, including the lay down areas for construction materials and
wind turbine components. It is currently
anticipated that only minor site clearance and formation will be required. The engineering design indicates that the
materials underneath the Project Site comprise poor quality fill overlying
rock. A reinforced concrete foundation
with pre-bored H-piles will be required.
The main construction activities at the Project Site are:
·
site
clearance and formation;
·
pre-bored
H-piling and construction of reinforced concrete foundation (about 9m x 9m x
2m) for the wind turbine;
·
erection
of wind turbine tower by assembling pre-fabricated steel tower sections;
·
installation
of nacelle and rotor blades using the cranes;
·
installation
of step up transformer and substation;
·
installation
of transmission cables between the substation and the 11 kV supply grid; and
·
testing
and commissioning of the wind turbine system.
The operation of the wind turbine, including start-up and shut-down,
will be automatic. It will produce
electricity when the wind speeds are in the range of 3 to 25 m s-1. The wind turbine brakes by full feathering of
the blades. The blades of the wind turbine
will be locked automatically when the wind speed is above 25 m s-1
to avoid damage.
The wind turbine will be unmanned and attendance by operational
personnel will only be required during emergencies or routine maintenance. All functions of the wind turbine will be
monitored and controlled remotely at the control room of one of CAPCO’s power stations or CLP Power’s sub-stations. Users with appropriate access rights can send
a Stop, Pause, Start or Reset command to the turbine using the remote control
system.
2.4
Planning and
Implementation Programme
The Project will be planned and implemented by CAPCO together with
consultants and contractors. Subject to
the review of the wind turbine feasibility assessment results and the ongoing
regulatory discussions with the HKSAR government
(**), the current envisaged key stages of Project are presented in Table 2.4a.
Table 2.4a Proposed
Project Programme
|
Key
Stage of the Project |
Indicative
Date |
|
EIA and Permitting |
Q2-Q4, 2006 |
|
Project construction ** |
2007 |
|
Operation of the wind turbine ** |
2008 |
3
Environmental Impacts
The environmental impacts associated with the construction and operation
of the Project are summarised in the following sections.
3.1.1
Construction Phase
The construction noise assessment indicates that the
predicted day-time noise levels at the NSR N1 (Hei
Ling Chau Correctional Institution) and NSR N2 (Hei Ling Chau Addition Treatment
Centre (Annex)) range from 36 to 75 dB(A) and comply
with the day-time construction noise criteria of 75 dB(A) (see Figure
3.1a).
Due to the close proximity of Correctional Services Department (CSD)’s
Staff Quarters (NSR N3) to the enabling work areas, the predicted day-time
noise level at this Noise Sensitive Receiver (NSR) will exceed the day-time
construction noise criterion by about 4 to 8 dB(A)
after implementation of the recommended mitigation measures. The duration of impact will be about one
week. As the affected dwellings will be
informed prior to the commencement of the construction and due to the
comparatively short exceedance period, the residual
construction noise impacts can be kept at reasonable levels. After consultation with CSD, the agreed
mitigation measures will be implemented (eg the use
of air-conditioners and avoidance of use of the affected staff quarter during
the period when works are being undertaken in the area). The contractor will closely liaise with the
CSD to programme the noisy construction works such that the noise impact to the
CSD staff will be avoided or reduced.
Noise monitoring will be carried out at NSRs
N2 and N3 during the construction phase.
It is not anticipated that construction work will be
undertaken at night-time and hence night-time construction noise impact is not
anticipated.
3.1.2
Operational Phase
The noise assessment indicates that under the worst-case scenario (covering
a full range of operation including start-up, shut-down, cut-in, cut-out,
braking and yawing; and the full range of wind speeds), with a wind turbine of typical sound power level of
104 dB(A) and with no tone, impulse and intermittence characteristics, the
predicted facade noise levels at the identified NSRs
will comply with the day-time and night-time noise limits at all NSRs.
Noise monitoring will be carried out at N2 for a period of 12 months
during the operation phase.
3.2.1
Construction Phase
The ecological impact assessment concluded that the ecological value of
the affected habitat ranged from low to moderate. The direct ecological impact due to the
construction of the wind turbine is expected to be low, and will not contribute
to any potential cumulative impact. In
view of the generally poor vegetation cover, it is anticipated that the Project
Site does not provide an optimal habitat for the Common Rat Snake and Bogadek’s Burrowing
Lizard and the impacts on these species are expected to be low. It is recommended that a search of the Common
Rat Snake and Bodagek’s Burrowing Lizard within the
Project Site and the impacted area of the access routes be undertaken
immediately prior to the commencement of the construction works. If these reptiles are identified, they will
be translocated to the adjacent shrubland
by a qualified person.
3.2.2
Operational Phase
Bird
collisions are perceived as an ecological concern during the operation of the
wind turbine. The results of the
literature review and baseline surveys indicate that the Project Site and the
areas in the vicinity are not important bird habitats as there is no wetland
habitat within or in the vicinity of the Project Site to attract water birds
and the Project Site is not within the travelling path
of the migratory birds. The potential risk of bird collision will
be low. It is therefore
considered that the operation of a single wind turbine will not cause adverse
impact to birds. Nevertheless, monthly
bird collision survey will be carried out during the first 12 months of
operation to confirm the findings of this EIA Study.
3.3
Landscape
and Visual Impact
3.3.1
Landscape Impact
Of the eight
Landscape Resources (including Shrubland,
The impacts on the
Landscape Character Areas of Hei Ling Chau will vary from slight for LCAs
2 to 5 (including Institutional
Landscape, Reservoir, Typhoon Shelter and Coastal Waters, respectively) to moderate for LCA1 (Island Landscape)
during construction and operation. The
impacts on the Landscape Character Area are acceptable as the assessment
indicates that there will be no significant impacts caused by the construction
and operation of the wind turbine.
3.3.2
Visual Impact
The potential
visual impacts due to the construction and operation of the wind turbine on
visual sensitive receivers within 10km radius of the Project Site have been
assessed. The wind turbine with the
proposed aviation warning marking scheme (ie
alternative orange and white bands) is in contrast to the surrounding natural
landscape. For Disneyland Hong Kong, the
visual impact will be negligible. VSRs from
3.4
Construction Phase Water Quality Impact
No marine works are associated with the construction and operation of
the Project. Due to the small scale of
the land-based construction works and the short duration of construction
period, the potential water quality impacts are negligible with the
implementation of general good construction site management practices. However, it is recommended that monthly site
audits be conducted to confirm no prohibited or polluted flows be discharged
from the works areas as described in the EIA Report.
3.5
Construction Waste Management Implications
The anticipated quantities of construction waste (400 m3),
chemical wastes (a few hundred litres, mainly consist of used lube oils),
sewage (1 m3 per day) and general refuse (26 kg per day) to be
generated during the construction phase of the Project will be small. With the implementation of general good
construction site practices, the construction of the Project will not cause
adverse waste management or environmental impacts with respect to the criteria
specified in the Technical Memorandum on Environmental Impact Assessment
Process (EIAO-TM).
It is recommended that monthly audits of the waste management practices
be carried out during the construction phase to determine if wastes are being
managed in accordance with the good construction site practices described in
the EIA Report. The audits should examine all aspects of
waste management, including waste generation, storage, recycling, transport and
disposal.
The literature review and field surveys confirmed the absence of any
3.7
Environmental Monitoring and Audit
3.7.1
Construction Phase
Noise monitoring and monthly construction site
audits will be carried out during the construction phase to check for
compliance with the relevant criteria.
3.7.2
Operation Phase
It is recommended to monitor noise levels at monthly intervals for first
12 months of the operation of the wind turbine. The monitoring frequency will increase to
biweekly intervals for the higher wind speed months (ie
winter months - from December to January, and storm season -July) within this
12-month monitoring period.
A bird collision survey (for a period of 12
months) will be carried out during the operation phase.
The environmental impact assessment has concluded that
no unacceptable environmental impacts are envisaged due to the construction and
operation of the Project.
Residual impacts associated with construction noise
have been evaluated and considered as low/negligible and acceptable in terms of the magnitude
and effects on health. No long term unacceptable impact on the
environment is anticipated.