NEWBURYPORT - The new electric car charging station is right out front at Massachusetts Audubon’s Joppa Flats Education Center. But on this sunny March afternoon, sanctuary director Bill Gette asked a visitor to follow him around back to a spot people don’t ordinarily go, to see the center’s electric meters.

“This is the meter for the photovoltaic cells on the roof. You see it’s turning really fast? This is recording the kilowatt hours that are being generated right now,’’ Gette said. “Now this meter over here, this is the meter from the grid. If we were using electricity from the grid, this meter would be turning that way. But it’s not; it’s turning backwards. So for right now, on this day, we are a net producer of electricity.’’

Not entirely coincidentally, users of the car charging station won’t pay anything for powering up the batteries of their Chevy Volts, Nissan Leafs (Leaves?), and other electric cars. Gette says Audubon has decided to make charge-ups free for at least a year, to encourage use.

Having your own power source helps. With those solar cells on the roof, the center generates an average of 40 percent of its electricity annually, Gette says. Both the charging station and the solar array are part of a larger initiative by the organization.

“Mass. Audubon has been making a major push to reduce its use of fossil fuels,’’ said Gette.

“One, it’s a very practical thing. It saves money, and we need to be good stewards of the money people donate,’’ he said. “And two, we’re concerned about, when you’re producing electricity by burning fossil fuels … it releases carbon into the atmosphere, and we believe that is having a detrimental impact on the environment.’’