If you haven’t already heard, yesterday saw the release of an important new report:

In the most comprehensive environmental assessment of electric transportation to date, the Electric Power Research Institute (EPRI) and the Natural Resources Defense Council (NRDC) are examining the greenhouse gas emissions and air quality impacts of plug-in hybrid electric vehicles (PHEV). The purpose of the program is to evaluate the nationwide environmental impacts of potentially large numbers of PHEVs over a time period of 2000 to 2050. The year 2000 is assumed to be the first year PHEVs would become available in the U.S. market, while 2050 would allow the technology sufficient time to fully penetrate the U.S. vehicle fleet.

Briefly, the study found that no matter what electricity generation profile you assume — i.e., no matter how much coal is involved — a large-scale shift to PHEVs would drastically reduce oil imports and GHG emissions.

The results are written up in, among other places, the L.A. Times and the San Fran Chronicle. Here’s a capsule summary:

Scientists … used computer models to simulate what would happen to emissions. They tested different scenarios based on how quickly Americans embraced the new hybrids and what type of energy — clean or dirty — was used by utilities.

The study found that if 60 percent of Americans shifted to plug-in hybrids by 2050, it would lead to an increase in electricity usage of 7 to 8 percent — a relatively small increase, indicating that hybrids would not necessarily require a surge of new power plant construction. Plug-in hybrids are charged mostly at night, when demand for electricity is low.

At the same time, the report estimates that electric hybrids would displace the need for 3 million to 4 million barrels of oil per day by 2050, more than twice what the United States imports each day from Saudi Arabia.

Researchers also found that plug-in hybrids reduced greenhouse gases no matter what energy source was used to produce the electricity, whether coal, nuclear, hydroelectric, wind or solar. Electric hybrids generated 40 to 65 percent less greenhouse gas than gas-fueled vehicles and 7 to 46 percent less than conventional hybrids.

Plug-in hybrids also would slightly lower air pollutants such as nitrogen oxide, sulfur dioxide and smog-forming ozone in most regions, the study found. But emissions of particulate matter could rise because of the increased burning of coal.

Good to see momentum building behind one of the few climate change solutions that’s an unambiguous positive.