Transmission System

BC Hydro’s transmission system moves electricity from generating stations to distribution substations, where it is transformed to lower voltages for distribution to customers. The BC Hydro high-voltage transmission system consists of 18,286 kilometres of transmission lines, operating at voltages from 60 kV to 500 kV.

The 500 kV bulk transmission network connects the major generators in the northern and southern Interior regions of the province, with the major load centres in heavily populated southwest B.C.

Electricity is supplied to the Lower Mainland and Vancouver Island from the Peace River hydroelectric system through Kelly Lake Substation, and from the Columbia River system through Nicola Substation. The relationship between installed generation capacity and electrical demand around the province drives the development and operation of BC Hydro’s bulk transmission system.

In May 2003, a new Crown company—British Columbia Transmission Corporation—was incorporated to maintain, operate and plan BC Hydro’s transmission assets. The core transmission assets are still owned by BC Hydro.

BCTC is completely independent of BC Hydro, with a separate and independent Board of Directors. Part of BCTC’s role is to ensure open and non-discriminatory access to the B.C. transmission system for all electricity producers.

The 500 kV bulk transmission system is planned and operated so that at any time, even during peak load periods, the system can withstand an outage of any single transmission line without loss of electrical load. There are exceptions to this rule, such as areas served by single radial lines. The bulk transmission system complies with industry planning and operating standards to ensure a high level of reliability.