July 21, 2011 - how the electricity supply mix affects air emissions

The types of generators making up your electricity supply mix vary from region to region and time to time.  How that mix is composed affects the air emissions associated with the electric power sector.

Yesterday, I looked at a mailing I recently received about the resources making up my electricity supply.  Also included in that fact sheet was this chart showing the average air emissions of carbon dioxide (CO2), nitrogen oxide (NOx), and sulfur dioxide (SO2) in pounds of emissions per megawatt-hour of power sold to customers:

The power sold through this standard offer period averaged 605.86 pounds of CO2 per MWh generated -- 34.5% less than the New England system average over the same time.  NOx and SO2 emissions were 0.52 and 0.94 lbs per MWh respectively -- each about half the emissions rate per MWh of the regional average.