Electric cars produce no tailpipe emissions, but their low overall carbon footprint can still be reduced even further.

The cleaner the power source used to charge an electric car, the cleaner the car becomes to operate.

However, for most owners, determining where the electricity used to charge their cars is coming from can be difficult.

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Cars charged off home circuits connected to the grid can end up drawing electricity from a variety of sources.

Now, charging equipment company eMotorWerks and nonprofit software developer WattTime believe they have a solution.

Working together, the two partners added software to a version of eMotorWerks' JuiceBox 240-volt Level 2 charging station that can prioritize the greenest power.

Juicebox Green mobile app

Juicebox Green mobile app

WattTime's software analyzes the grid in real time to identify when the cleanest possible sources are available to provide power for charging.

That includes renewable sources like wind and solar, or more-efficient conventional power plants.

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The JuiceBox Green 40 charging station can then schedule charging sessions to take advantage of these cleaner sources.

Many electric-car owners already use control software to delay charging in order to take advantage of off-peak rates, but apparently it can be as useful for cutting carbon emissions as it is for cutting costs.

Juicebox electric-car charging station

Juicebox electric-car charging station

The new green feature joins eMotorWerks' existing JuiceNet, which can manage charging times and rate of charge in correspondence with a specific user profile.

Systems like this give owners more flexibility--something that goes well beyond pulling up to a gas station and selecting "regular" or "premium."

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And by prioritizing green energy sources, owners can continue to lower the environmental impact of their cars.

That should become easier over the next few years.

Coal currently makes about 40 percent of the U.S. generation mix, but that's expected to decrease as utilities switch to cheaper natural gas, and increase the use of renewable sources.


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