for renewable
energy. Issues relating to the operation
of Helipad CC03 have been resolved in consultation with the Government Flying
Services (GFS) and Civil Aviation Department (CAD). It is therefore recommended that Hei Ling
Chau be included in the short list of potential areas for further evaluation.
Summary of the Screening of the 59
Potential Areas with the Third Highest Wind Resource
The screening process was repeated for the 59 potential areas with the 3rd
highest wind resource in order to identify another site for further
consideration. Using the same screening
procedures, 7 interim short-listed areas (including South of Tung Chung, Lo Fu
Tau, Ha Shan Tuk, East of Sha Lo Wan, Black Point, Hei Ling Chau and Shan Mei)
were identified.
The potential area at Black Point (see Figure
2.2y) encroaches on the proposed WENT Landfill Extension
which is an important component of future waste management strategy for
Site visits were
undertaken to the other 5 potential areas.
The entire areas of the South of Tung Chung and Lo Fu Tau sites are
within a gazetted proposed
The Ha Shan Tuk
site lies within a “CA” zone (see Figure 2.2ac), and therefore
is subject to the rezoning application process under the Town Planning
Ordinance and the statutory Environmental Impact Assessment (EIA) process
even for the installation of a wind monitoring station. The requirements for the above statutory
processes introduce additional uncertainties into the project programme. It is therefore not recommended for further
evaluation.
The Shan Mei site
(see Figure 2.2ad) is small and
is relatively close to overhead power transmission lines and inhabited
buildings in
Access to Hei Ling Chau site (see Figure 2.2ae) is not a concern since regular
educational visits to the island are currently organised and supported by
Correctional Services Department (CSD) using an established system managed by
CSD. CSD is also implementing an
Environmental Management System at these correctional institutions and the
department has expressed its initial support Site Screening Process
Table 2.2c summarises the site screening exercise
and outlines how the short-listed sites are identified.
Table 2.2c Summary
of the Site Screening Exercise
|
Step |
Potential
Areas Reviewed |
Screening
Method |
Result |
|
1 |
Entire CLP Power supply area (on land only) |
Constraints mapping and wind energy
resource mapping. Checking of compliance with aviation height restriction |
73 potential areas (14 areas with the 1st
and 2nd highest wind energy resource and 59 areas with the 3rd
highest wind energy resource) 2 Stakeholder (NGOs) consultation
workshops to discuss the site screening exercise and findings. Relevant Government Departments have also
been engaged. |
|
2 |
A long list of 14 potential areas with
the 1st and 2nd highest wind energy resource |
Comparative assessment using ranking
criteria and eliminates areas with low score |
An interim short-list of 8 potential
areas for further consideration |
|
3 |
An interim short-list of 8 potential
areas |
Observations from site visits |
A short-listed of 2 potential areas for
further consideration |
|
4 |
A long list of 59 potential areas with
the 3rd highest wind energy resource aiming to identify another
potential area to achieve a total of 3 potential areas |
Comparative assessment using ranking
criteria and eliminates areas with low score |
An interim short list of 7 potential
areas for further consideration |
|
5 |
An interim short list of 7 potential
areas |
Observations from site visits |
Identified 4 potential areas at Hei Ling Chau,
Shan Mei, South of Tung Chung and Lo Fu Tau for further consideration |
|
6 |
6 potential areas (including 2 identified
from Step 3 and 4 identified from Step 5) |
Stakeholders consultation and further
assessment taking account of stakeholders’ feedbacks |
A short list of 3 potential areas
including Robin’s Nest, Kau Sai Chau and Hei Ling Chau was recommended for
further consideration. Relevant
Government Departments have been engaged and updated the findings of the site
selection processes. |
|
Note: (a) Twenty-five
stakeholder consultation or liaison meetings (including NGOs, ACE, CAD, GFS,
CSD, PlanD, EPD, EMSD, LandsD) were held.
A list of the stakeholder meetings held is presented in Annex E. |
|||
Further Review of the Robin’s Nest Site
The
existing vehicular access from Wo Keng Shan Road to the peak of the Robin’s
Nest is via a very steep (some sections with a gradient greater than 20%), long
(about 3km) and narrow single-track access road. Concerns were raised regarding vehicular access to the Robin’s Nest
site. A more detailed review of the
engineering constraints associated with the delivery of the wind turbine to the
site was undertaken and concluded that the risk posed to the safety of the construction
workforce and the integrity of the equipment was excessive. The ascent of the delivery vehicles would be
difficult and dangerous, particularly at certain bends where there is limited
space for a vehicle to turn, even if the roads were upgraded. This site was therefore eliminated from
further consideration.
Alternative
Sites for Development of the Wind Turbine
The site selection process has identified that Kau Sai Chau and Hei Ling
Chau be selected for further consideration.
In a comparative assessment of the two sites, the relative merits of the
sites were evaluated with respect to wind resource, engineering, environmental ([5]), planning and economic
considerations. For the wind resource
consideration, wind monitoring stations were constructed at these sites to
collect site specific data. The wind
monitoring programme indicates that the wind resources at Kau Sai Chau and Hei
Ling Chau are substantially the same.
Due to the topography of the Kau Site Chau
site, the construction of the access road for the Kau Sai Chau site is expected
to be much more complex (in terms of length of the access road, vegetation
clearance, extent of slope works, steep gradient, etc) than that for Hei Ling
Chau site. The water depth at the Kau
Sai Chau pier is shallow and will only be accessible to construction barges
during high tide. It may therefore
require delivery of the plant and equipment at restricted hours. From an engineering perspective, it is
considered that Hei Ling Chau site is preferred to the Kau Sai Chau site.
An initial assessment of the potential environmental impacts associated
with the construction and operation of the wind turbine at each of the sites
revealed that there are no insurmountable environmental impacts for both
sites. However, the construction of
the access road at the Kau Sai Chau site will require clearance of a larger
area of vegetation and will entail a relatively larger environmental impact
overall. Therefore, the Hei Ling Chau
site is preferred to Kau Sai Chau site in terms of environmental consideration.
Due to the close proximity of the existing pier at Kau Sai Chau (which
will be used to deliver the construction plant and equipment) to the fish
culture zone, there may be concerns from the fishermen. This will increase the degree of uncertainty
in the development programme and may delay the Project. The Kau Sai Chau site also requires a longer
construction period and higher capital cost.
Taking into consideration the overall merits of the two sites with
respect to wind resource, engineering, environmental, planning and economic
considerations, the Hei Ling Chau site demonstrated advantages over the Kau Sai
Chau site. Therefore, although both the
Hei Ling Chau site and Kau Sai Chau site are both feasible sites for the wind
turbine pilot demonstration, the Hei Ling Chau site is selected as the
preferred site.
2.3
Consideration of
Alternative Locations for the Project Site
Figure 2.2ae shows the potential area on Hei Ling Chau
for development of the wind turbine.
The area is at the southern end of the island and is away from any
inhabited facilities.
At the northern end of the potential area is a helicopter landing pad
that is used by the Government Flying Services (GFS), mostly as a landing point
in the event of an emergency on the island.
The approach and exit paths to the helipad are shown as the area between
the two red lines. The wind turbine
must not intrude into this zone. Pursuant to consultations with GFS, a
separation distance of at least 150m between the centre of the wind turbine
tower and the helipad should be provided.
Hei Ling Chau falls within the Hong Kong Airport Height Restriction
Zone. At the northern end of the
potential area, the level of the zone is at 169 mPD, while at the southern end
the level is 164 mPD. CAD has advised
that they have no adverse comment on the proposed location, provided the wind
turbine overall height is in compliance with the airport height restriction and
suitable lighting and markings on the turbine are adopted.
2.3.1
Potential Locations for the Project Site
The majority of the potential area is vegetated and hilly with little or
no established means of access. The
tallest peak is on the western side of the area, while to the east the land
falls away to the sea. At the north end
there is a contractor’s storage area, which has been subject to re-grading and
is relatively flat.
The ‘peak’ area is not preferred due to:
·
potential
wind shear effects;
·
the
need for large amounts of earthworks that would be necessary to form an access
to the site and a working platform for construction; and
·
the
higher ground level (about 120 mPD) and lower airport height restriction zone
(about 164 mPD) which would limit the height available for the turbine to
around 44m, which is not acceptable.
The ‘valley’ area is not preferred due to:
·
the
need for large amounts of earthworks that would be necessary to form an access
to the site and a working platform for construction; and
·
the
shielding effects of the higher ground to the north, when the wind is from that
direction.
The ‘ridge’ area is not preferred due to:
·
the
need for earthworks that would be necessary to form a working platform for
construction; and
·
the
higher ground level and lower airport height restriction zone which would limit
the height available for the turbine.
The preferred location is the Contractor’s Storage Area as:
·
it is
directly accessible from existing, paved access roads;
·
it is
relative flat and minimal earthworks would be required to form a working
platform;
·
its
level at about 70mPD together with the airport height restriction at about 169
mPD allows a turbine height of approximately 100m;
·
it is
not shielded from prevailing winds and would be unlikely to be subject to wind
shear or other turbulence; and
·
it is
noted that the wind monitoring mast was located in the contractor’s storage
area and therefore no extrapolation of wind data will be necessary if the
turbine is also located there.
2.3.2
Alternative Site Layout and Size
Although the turbine, when
erected, will occupy relatively little land, the area needed during
construction and erection will be larger in order to accommodate cranes and
provide space to place the turbine components prior to their being lifted into
place. The basic size requirement (about
90m x 50m (4,500m2) and generic site layout are shown in Figure 2.3a. It need
not necessarily be of this shape and could be reconfigured to suit a site’s
particular constraints, but the overall area required would remain essentially
the same.
It is also important that to allow the turbine
components to be safely off-loaded and stored and to enable safe and secure
handling and lifting of the components, the site area should be relatively
flat.
During
the development of the erection scheme, the site layout requirements were
developed based on the likely size of wind turbine to be adopted. This indicates that a slightly large area is
required for the crane assembly. The
minimum length of crane jib to be fabricated on the ground is around 90m
long. This length together with the
storage space and site width of about 50m determined the size of temporary
works site area that is required.
Figure
2.3a Basic Size Requirement and
Generic Layout of Wind Turbine
The
actual area indicated in Figure 3.1b is 100m x 54m to allow for a slight variation in
typical plant employed locally from
As can be seen from Figures 2.4d and Figure 3.1b, any existing flat land adjacent to the access
roads has already been occupied by CSD facilities. The existing CSD’s contractor storage area
satisfies the basic size requirement and is relatively flat which minimises the
site formation works and direct impact on the adjacent habitats. The proposed layout ensures that the wind
turbine is at least 150m away from the 220o or 100o
flight sector of the helipad (see Figure 2.2ae). If the
orientation of the site is rotated about 90o anti-clockwise (ie
Option 1 in Figure 2.3b), the site layout could still fit within the
contractor storage area without significant vegetation clearance. However, the wind turbine will be too close
(ie <150m) to the approach and exit sectors of the helipad. It will not be acceptable to GFS and
CAD. If the proposed site layout is
rotated about 45o (ie Option 2 in Figure 2.3b), the wind turbine tower will be 150m away from
the 220o line of the GFS helicopter approach sector. However, it will require significant earthworks
and clearance of vegetations which are not preferred.
The environmental benefits associated with this
proposed site layout include:
·
minimising
the potential impacts on existing flora and fauna as the area is currently used
as a contractor storage area; and
·
minimising
site formation works and hence potential surplus of excavated material
requiring off -site disposal;
Figure
3.1b is
considered as the preferred layout and adopted in this EIA Study.
2.4
Consideration of
Alternative Delivery Modes and Routes
2.4.1
Marine Access
There are two existing jetties on the Hei Ling Chau Island. One is located at the northern part of the
island near the Hei Ling Chau Refuse Transfer Station. The other is at the southern side of the
island near the Hei Ling Chau Addiction Treatment Centre (Annex). A hydrographical survey has been carried out
at the existing berthing facilities (see Figures 2.4a to
2.4c) confirmed that there are sufficient water
depth at both jetties and hence no dredging of the approach channel and/or the
berthing area will be required.
2.4.2
Air Lifting
Airlifting of the key wind turbine components (blades (up to 5 tonnes
each), tower sections (up to 42 tonnes each) and nacelle (up to 43 tonnes)) to
the Project Site has also been considered.
If this is possible, it will avoid or reduce the enabling works for the
existing roads or avoid building a new access road. The largest, commercially available, heavy
lift helicopter in this region has a maximum lift capacity of about 20
tonnes. Therefore this method is not
feasible for the lifting of the tower section and nacelle.
The commercially available helicopters in Hong Kong have a maximum lift
capacity of about 1 tonne and therefore will not be able to lift the blades to
the Project Site. There will be considerable logistical problems
in getting a suitable size helicopter to Hong Kong at the time of the blade
erection and some considerable advance planning will be required. Even if the blades can be airlifted to the
Project Site, it cannot avoid the need for enabling works for the existing
roads or building a new access road for the transportation of the tower
sections and nacelle. It is therefore
considered that airlifting of the nacelle and tower sections is not
feasible.
2.4.3
Road Access
Existing Road Network on Hei Ling Chau
The road infrastructure is
well-established and the potential area can be easily reached by road. However, the size and weight of the of the
wind turbine components (nacelle, blades and steel tower sections) to be
transported and the necessary crane for erection of the wind turbine will have
a significant impact on the existing or proposed transport routes.
An initial transportation study has been carried out to determine the
feasibility and impact of the transportation of the larger components to the
island sites by marine and overland transport.
Further study, in conjunction with a transportation contractor, has also
been undertaken to allow the impacts of such transport to be minimised.
Items to be Transported
Turbine
Components: The turbine components adopted for the
purposes of the transportation assessment will be those as described in Section 3. In particular, the critical sections are as
follows:
·
Blades
at up to 30m long and 5 tonnes in weight;
·
Tower
sections, up to 4m in diameter, up to 23m long and up to 42 tonnes;
·
Nacelle
at up to 12m (L), 4.5m (H), 3.6m (W) and 43 tonnes.
Construction
Plant and Equipment: In addition to the wind turbine components,
construction plant and equipment will need to be transported to the Project
Site. The critical item is the crane for
the erection of the wind turbine. A
CKE2500 crawler or similar crawler crane will be required to lift the nacelle
(up to about 43 tonnes) to the top of the tower (at a height of 60m above
ground level).
Assessment of Options
It is preferred to use the existing access road for the transportation of
all the plant and equipment, as far as practicable. The island currently uses an informal one
way system on the existing road network.
To reduce the disturbance to the CSD’s operation on the island, it is
preferred to follow the one way system.
Two alternative routes (see Figure 2.4d) were considered:
·
Long
access route where large components are delivered to the existing berthing
facility at the north of the island, then transported along the existing road
network;
·
Short
access route which includes constructing a temporary platform at the existing
jetty at the south of the island, and a temporary steel bridge next to the
platform. The plant and equipment will
be unloaded from the barge to the temporary platform and then lifted to the
deck of the bridge by a mobile crane.
The equipment will then be transported to the Project Site using the
existing road.
Assessment of Alternative Routes
The
transport of the large components that make up the wind turbine requires heavy
duty transport vehicles and roads that are wide and straight with bends of
large radii. The road along the long
route is typically 3m wide and less at some sections with tight bends which
cannot accommodate the heavy duty transport without significant impact to
slopes, structures and trees. The width
of the transport vehicle itself is 3m and the lower tower sections are even
wider than the transport vehicle at up to 4.1m in diameter. Similarly, the nacelle diameter is up to 4.5m
wide and would also be wider than the road and transport vehicle. The narrow road and tight bends also
restricts the length of the vehicle. The
towers sections are up to 23m long and the blades are 30m long and hence would
require an extra long heavy transport vehicle and straight roads and
bends. To provide for this the roads
have to be widened to provide extra width and to straighten the bends.
To
accommodate the transport of the large turbine components, widening and
clearance of trees and structures will generally be required for the whole
length of the long access route (about 2.5km).
Therefore the level of impact to environment of slopes, trees and
structures is significant. In addition,
the long access route is the main access road to a number of facilities on the
island. Any major road upgrading works
will have significant impacts on the CSD’s operation on the island.
Transporting wind turbine components, especially the tower sections by the
long access route, is not preferred as this option will have a significant
impact on the existing road network, local environment and CSD’s
operation.
The short access route is the preferred route for transporting the wind
turbine components (ie nacelle, blades and steel tower sections) as it will
only involve construction of a temporary platform, a bridge and minor road
upgrading works. The impacted areas
due to construction of the footings of the temporary bridge (about 5m x 5m
each) are small. However, in order to
construct the short access route and lift the wind turbine components from the
temporary platform to the deck of the bridge, it is necessary to deliver a
mobile crane and a self-propelled transporter using the existing long access route. It is therefore still required to upgrade
the some sections of the existing long access route for the transportation of
these equipments.
The degree of enabling works (in terms of the number and extent of slope
works) along the long access route will be significantly reduced if a
combination of the long and short access routes are adopted.
Taking account of the engineering feasibility and the need to minimise
the potential environmental impacts associated with the road upgrading works,
the best access option will therefore be the use of:
(a)
the
long access route to deliver the general construction plant and equipment, and
construction workers; and
(b) the short access route to unload and
transport the wind turbine components.
2.5
Consideration of
Alternative Aviation Warning Marking Schemes
As discussed in Section 2.3, there is a helicopter landing site
“CC03” that is used by the GFS at the north of the Project Site. Although the Project Site location is
outside the approach and exit zones of the helicopter flight path for this
landing site, the Project site is located in proximity to the helicopter
landing site “CC03” and the Hong Kong - Macau helicopter route A (see Figure 2.2ae),
thus, CAD requires that the wind turbine be provided with suitable lighting and
markings (alternative orange and white bands). The marking will alert the helicopter pilot
the presence of the wind turbine but will also increase its visual intrusion.
A number of marking schemes (see Figure
2.5a) were developed which aim to provide the necessary
warning to the pilot but also to make it less visual intrusive. A number of Government departments were
consulted, including EPD, Planning Department and CAD to assess the
alternatives.
When analysing the visibility of the marking schemes, it is clear that
Option 1 would have the highest visibility, with Option 6 and 8 having the
lowest visibility. Consultations with
CAD indicated that only Options 1 to 3 would be acceptable. As the hub and nacelle represents the largest
visible elements from a distance, no marking on these elements is desirable.
Therefore in order to reduce the impact of the markings, Option 3 was chosen
as there are no markings on the nacelle, as shown in Option 2, and the hub of
the blades is also unmarked, as shown in Option 1. The consultation resolved that Option 3 is
the least visually intrusive marking scheme while satisfying the aviation safety
requirements of CAD.