EN30(1) Sulphur Hexafluoride Gas Inventory and Emission Rate

Calendar Year	2000	2001	2002	2003	2004
In-use Inventory (kg)	111,977	111,977	111,977	112,736	110,677
Emission Rate (% of in-use inventory)	3.01	2.96	2.42	2.88	2.55

Sulphur Hexafluoride (SF ₆) is used to cool and insulate electrical equipment to prevent arcing and outages. It is also a powerful greenhouse gas, with a global warming potential 23,900 times that of carbon dioxide. To date, no commercially-viable substitute has been found. The emission rate shown includes all known losses, whether due to slow leaks, maintenance or accidents. Overall, the emission rate is improving due to enhanced materials handling training, better records, and replacement of older equipment.