Forthbank Wind Energy Development - Partnerships for Renewables

Forthbank Wind Energy Development
4.6 Electrical Connection
Off-Site Grid Connection
4.6.1 The proposed wind energy development will be connected into the local distribution system.
Analysis and discussions with the local distributed network operator (DNO) (SP Energy
Networks) indicate that a viable grid connection can be made to Kelliebank Primary Substation
by underground cable at 11kV. The target date for completion is March 2012.
4.6.2 Details of this connection are currently being confirmed by SP Energy Networks. The grid
connection for the proposed wind energy development will be subject to a separate application
to the Scottish Government Energy Consent Unit (including consideration of the environmental
effects) under the Section 37 of the Electricity Act 1989 and as such is not discussed in detail
in this ES. Figure 4.9 provides the indicative connection route at this stage (approximately
1.955km).
Control Building and Electrical Substation
4.6.3 The proposed wind energy development will be connected through suitable switchgear to be
installed in a small control building on-site. The control building compound will comprise a
hard standing with maximum dimensions of 40m x 30m, and a single storey building
approximately 5m x 15m x 3.81m which will house switchgear and metering, protection and
control equipment and also welfare facilities. The building will be finished in a render which
matches the colour of existing buildings in the area. Figure 4.3 and 4.4 provide an illustration
of a control building plan and elevation respectively. The proposed location of the control
building and compound is shown in Figure 1.2.
4.6.4 The control building will also contain a single toilet and hand wash facility. The water for
flushing the toilet will come from a rainwater collection tank located within the compound. It is
likely that waste materials will be disposed of to a septic tank. The appropriate CAR
registration will be sought from SEPA. This is discussed further in Chapter 13 (Hydrology,
Hydrogeology and Geology).
Electric Connections On-Site
4.6.5 Wind turbines produce electricity at 690v which is typically transformed to 11kV or 33kV via the
turbine transformers located outside the turbine bases.
4.6.6 Underground cables will link the turbines to the on-site control building. Detailed construction
and trenching specifications will depend on the ground conditions encountered at the time, but
typically cables will be laid in a trench 1000mm deep and 400mm to 1200mm wide. To
minimise ground disturbance, cables will be routed alongside the access tracks wherever
practicable and if not, the total footprint of construction activity will be stated. Where the trench
is laid in the landfill cap, construction details will be agreed with SEPA to maintain the cap
integrity and limit surface water ingress into the landfill. Approximately 2.245km of cable
trenches will be required on-site to connect the turbines to the on-site control building. Figure
4.5 shows a typical cable trench detail.
November 2010 Chapter 4 Page 5
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