Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

Plug-in hybrids may one day constitute a majority of the cars on U.S. roads. Like today’s hybrids, they have both a gasoline engine and an electric-drive motor whose batteries can be recharged by the engine. But they can also be recharged at a standard wall socket. Given that they’ll raise electricity demand and increase power-plant emissions, will they really reduce overall ­greenhouse-gas production? It turns out that plug-ins always result in lower emissions than conventional cars do, and they beat regular hybrids handily–except when the electricity comes from coal (the source of 43 percent of U.S. electricity), according to a study. But as gasoline comes from dirtier oil sources, such as tar sands, plug-ins may win even when powered indirectly by coal, one study author says.

6 comments. Share your thoughts »

Credit: Car Culture/Corbis

Tagged: Energy

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me
×

A Place of Inspiration

Understand the technologies that are changing business and driving the new global economy.

September 23-25, 2014
Register »