In May 2007, after careful consideration of the alternatives, including feedback received over the year, an environmental review, and engineering and costing analyses, BCTC decided that it would seek the necessary approvals to construct a new 500 kV alternating current (AC) transmission line, mostly along the existing right-of-way from the Nicola Substation near Merritt to the Meridian Substation in Coquitlam - the largest expansion to B.C.'s transmission system in 30 years.
New 500 kV Transmission Line
To ensure that we can continue to meet the electricity needs of growing communities in BC's Lower Mainland, BCTC has studied alternatives to reinforce the capacity of the transmission system between the BC Interior and the Lower Mainland by 2014.
BCTC is proposing to build a new 500 kV transmission line mostly along an existing right-of-way between the Nicola Substation (NIC) near Merritt and the Meridian Substation (MDN) in the Westwood Plateau area in Coquitlam.
The proposed new transmission line will parallel an existing 500 kV transmission line for most of its approximately 240 km length. When the existing line was installed in the early 1970s, sufficient right-of-way was acquired at that time in anticipation of future growth and the possible need for an additional line.
The new line will require a Certificate of Public Convenience and Necessity (CPCN) from the British Columbia Utilities Commission (BCUC) and environmental certification from the BC Environmental Assessment Office (BCEAO).
Other Transmission Alternatives Studied
Before deciding upon a new 500 kV transmission line, BCTC studied several other options. Some of the alternatives studied included:
- An additional 500 kilovolt (kV) transmission line proposed mostly along an existing right-of-way between Nicola Substation near Merritt and Meridian Substation in Coquitlam
- A package of upgrades to existing transmission lines and station facilities located between the Interior and the Lower Mainland.
Deciding on a Preferred Alternative
BCTC used a number of criteria to evaluate the alternatives, including:
- Technical
- Financial
- Environmental
- Property/ROW
- First Nations Considerations
- Stakeholder Considerations
In deciding to pursue the new transmission line alternative, BCTC believes that it has selected the alternative that is the most effective and energy-efficient solution to increase the province's transmission capacity.
Evaluating the Alternatives - Key Findings
- The New Line alternative performed better on the key technical performance criteria and reduces line losses. Line losses is the amount of power lost as the electricity flows through the wires; the higher the losses, the more generation must run to compensate.
- The New Line and Upgrade alternatives ranked similarly on First Nations and stakeholder considerations.
- Environmental impacts associated with all alternatives can be managed by proper planning and design and implementation of best practices.
- The Upgrade alternative has lower property and right-of-way (ROW) considerations.
- The New Line alternative is less expensive on a net present value (NPV) basis than the Upgrade Option. Net present value (NPV) is a standard method for the financial appraisal of long-term projects. Used for capital budgeting, and widely throughout economics, it measures the excess or shortfall of cash flows, in present value terms, once financing charges are met.
BCTC will be required to present its assessment of alternatives in its application for approval of the ILM Project to the British Columbia Utilities Commission (BCUC). Ultimately, the BCUC has the final decision-making authority on whether to approve BCTC's recommended solution and may choose an alternative solution, or combination of solutions.
Upgrades to Existing Transmission Lines and Station Facilities
One of the alternatives studied was a package of upgrades to four existing transmission lines and station facilities between the Interior and the Lower Mainland. These upgrades would allow more electricity to travel through these already existing circuits.
See the Alternatives Map for the location of circuits that were proposed to be upgraded.
These upgrades would have involved replacing some of the existing wires with higher capacity conductors. When more electricity moves through the wires, the wires heat up causing the wires to sag more. In order to maintain the required distance between the wires and the ground for the circuit to operate safely, it may have been necessary in some locations to add some new towers, raise some existing towers, or recontour the ground under the wires by removing a half metre to one metre of ground.
This alternative would also require a CPCN from the BCUC. All work associated with the upgrades would take place within existing rights-of-way and substation boundaries and would be carried out under BCTC's environmental management policies and practices.