Our calculation of the emission factors for power generation is based on information provided by the International Energy Agency IEA (IEA Electricity Information 2009) regarding gross energy generation and net losses, on information from the Intergovernmental Panel on Climate Change (IPCC) regarding fuel-based emission factors, and on our own analyses of efficiency factors in power generation.

Here’s an example of how this calculation is made. New combined cycle power plants, fueled by natural gas, achieve an efficiency rating of about 58 percent. They emit about 345 grams of carbon dioxide per kilowatt hour. This figure is based on the carbon content of natural gas, the conversion of carbon into carbon dioxide during combustion, and the plant’s efficiency rating. As a basis of comparison, we use the average global emission factor (for all energy sources) of 587grams carbon dioxide/kWh for power generation. The total emission reduction equals this difference multiplied by the number of kilowatt hours of electricity that our newly installed power plants generate in a fiscal year.

In calculating emission reductions at our customers, we focus on carbon dioxide reductions during consumption.* For each product and solution installed within a fiscal year, we calculate the emission reduction in a typical application for the entire fiscal year. The carbon dioxide emitted during the manufacture of individual products in our factories is included in our own carbon footprint and is therefore excluded from the calculation presented here.

* For gas-insulated switchgear, we also convert sulfur hexafluoride emissions into carbon dioxide equivalents, enabling us to compare total systems.