Greenhouse Gas Emissions
The northeast region is unique in many ways. We have our own set of energy challenges. Our geography ranges from remote, mountainous terrain to dense, urban environments. We experience a wide variety of weather extremes from ice storms to heat waves. Our renewable resources are plentiful but unevenly distributed.
As the leading supplier of energy in the northeast, Northeast Utilities (NU) brings more than 100 years of experience and an in-depth knowledge of our region and its energy needs. We welcome the opportunity to be part of the energy transformation currently under way.
The carbon intensity of the electrical grid in New England is among the lowest in the country, yet we continuously strive for improvement. NU will drive decarbonization of the regional grid through reduction of greenhouse gases (GHG) in three broad areas:
(1) Reducing traditional, end-use energy consumption
This includes expanding energy efficiency, appropriate deployment of smart grid and related infrastructure; and providing customers with information, management tools and pricing options to reduce end-use consumption.
(2) Adding renewables to the energy mix either through generation or transmission expansion
This includes expanding renewable and low-carbon generation through direct investment as well as developing infrastructure to bring renewable and low-carbon resources to market and offering clean energy options to our electricity customers at CL&P, NStar, PSNH and WMECo.
(3) Using electricity or natural gas for non-traditional end uses, such as transportation
Non-traditional end uses for electricity and natural gas include transportation alternatives and deployment of associated infrastructure to support electric vehicle charging and natural gas vehicle fueling. Other non-traditional end uses also include promoting conversion from fuel oil to natural gas, geothermal heat pumps and solar thermal for home heating.
NU’s GHG emission inventory accounts for and reports all direct carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and sulfur hexaflouride (SF6) emissions for operations of NU and its subsidiaries. The general emission source categories included in NU’s GHG inventory are stationary combustion sources; mobile combustion sources; indirect emissions from purchased electricity, transmission and distribution losses; fugitive CH4 emissions from process equipment including pipelines for natural gas transmission and distribution; and fugitive SF6 emissions from equipment related to electrical transmission and distribution.
Direct or "Scope 1" GHG emissions are those from sources owned or operated by NU. For example, direct emissions include exhaust stacks and emissions from process vents. Indirect or "Scope 2" GHG emissions are those that are a consequence of NU’s activities, but occur from sources owned or controlled by others. For NU’s operations, indirect emissions refer to emissions from purchased electricity and line loss during the transmission and distribution of electricity. NU's company-wide SF6 emission rate is estimated to be 1.4% (63% below the industry average of 3.8%).
"Scope 1," or direct emissions, account for most of our CO2 emissions. The following table summarizes NU’s "Scope 1" CO2 - equivalent (CO2-e) emissions for 2012. NU reports GHG emissions to the Carbon Disclosure Project (CDP) .
| Source1 | Metric Tonnes of Emissions in 2012 | ||
|---|---|---|---|
| NStar | NU Other | Combined | |
| Generation Stationary Combustion2 | NA | 1,460,058.2 (PSNH) | 1,460,058.2 |
| Non-Generation Stationary Combustion | 2,456 | 10,544 | 13,000 |
| Mobile Sources | 14,141 | 29,628 | 43,769 |
| Gas Distribution Leakage3 | 80,840 | 67,656.6 (Yankee Gas) | 148,496.6 |
| Sulfur Hexafluoride (SF6) Leakage4 | 14,739.1 | 30,970.82 | 45,709.92 |
1NStar uses the Climate Registry methodology to calculate emissions, while the other NU operating companies use the WRI model to calculate the emissions. This may result in some differences in the results that will be seen when the companies merge their GHG inventories using 2013 data.
2Generation emissions are summed from USEPA reporting for Subparts C and D.
3Gas Distribution emissions are from USEPA reporting for Subpart W.
4SF6 emissions are from USEPA reporting for Subpart DD.
Greenhouse Gas Emissions Archive
Climate Change
We are continually evaluating the risks presented by climate change. Connecticut, New Hampshire and Massachusetts are each members of the Regional Greenhouse Gas Initiative (RGGI), a cooperative effort by ten northeastern and mid-Atlantic states to develop a regional program for stabilizing and reducing CO2 emissions from fossil fuel-fired electric generating plants. NU participated in a two year RGGI program review that resulted in an updated RGGI Model Rule released in February 2013 that will guide future updates to state CO2 Budget Trading Programs.
Global climate change could potentially impact weather patterns such as by causing an increase in the frequency and severity of storms or altering temperatures. These changes could affect our facilities and infrastructure and could also impact energy usage by our customers. Natural disasters happen regularly in all parts of the world, including the northeast. Anticipation and planning are keys to being able to respond quickly and NU and its subsidiaries are constantly working to be adequately prepared.
"Although the carbon intensity of the New England electrical grid is among the lowest in the country, we continuously strive for improvement."