Electricity and Carbon Footprint

A common misconception is that because BC's electricity supply is primarily from renewable sources like large hydro that saving electricity does not really have much effect on greenhouse gas emissions. Perhaps this is why there has not been a strong enough push for electricity energy efficiency projects in BC as part of meeting climate goals.

The reality is quite different than this misconception. BC Hydro's electricity grid is connected to other grids in western Canada and the western US. Savings in electricity use in one area therefore have the effect of avoiding electricity generation in another area. This effect is dynamic and complex. But the key point point is that the effect on greenhouse gas emissions of saving electricity in Vancouver, or BC at large, is not just confined to BC Hydro's resources.  

BC Hydro set this out in its Environmental Impact Statement of its Site C dam project when describing the carbon footprint effect the Site C dam would have - in this case of the added electrical supply of a hydro dam:

"...BC Hydro’s trading region for electricity is the Western Electricity Coordinating Council (WECC), which includes Alberta and all of or parts of 14 western US states. The energy that is exported to external markets would avoid GHG emissions based on the GHG intensity of the generation in these other markets. The Western Climate Initiative 2008 Default Emissions calculator estimates the marginal GHG emissions from the WECC grid (which BC is a part of) to be 0.443 tonnes of CO2 equivalent per MWh...."

Greenlight Canada uses this emissions factor in its estimate of the long term carbon savings from its LED retrofit projects.