EN30(1) Sulphur Hexafluoride (SF6) Gas Inventory and Leakage Rate
| Calendar Year | 2003 | 2002 | 2001 | 2000 |
| In use inventory (kilograms) | 112,736 | 111,977 | 111,977 | 111,977 |
| Leakage rate (percentage of total inventory) | 2.1 | 0.7 | 1.4 | 1.1 |
SF 6 is used to cool and insulate electrical equipment to prevent arcing and outages. It is also a powerful greenhouse gas with no viable substitute. In 2003 10 older circuit breakers were replaced with modern equipment containing less than half of the SF 6 of old breakers and with an escape rate of less than 0.5 per cent. As a result of these and other repairs done in 2003, BC Hydro expects leaks to be reduced in 2004 and beyond. The leakage rate shown does not include maintenance or accidental losses. The increase in leakage rate was due to a significant increase in losses from 338 kilograms last year to 1,379 kilograms this year at Mica Generating Station, despite precautions taken to minimize escapes.
Last Modified: Jun 30, 2004
