The Environmental Protection Agency is eager to see some utility data on the positive environmental impacts of smart grid deployments around the country. Just what it wants to do with the data is still up in the air.

That's the gist of comments EPA representative Stacy Angel made in a Thursday conference call hosted by the Electric Power Research Institute.

"What I would like is to see results from the deployments of where environmental benefits have been achieved," Angel said. Perhaps the utility industry could create a clearinghouse for such data, she suggested.

Estimates of the smart grid's impact on reduced greenhouse gas emissions, pollution from fossil fuel-fired power plants, and overall energy efficiency gains are all over the place.

A big one, EPRI's Green Grid study from last year, put the potential energy savings at 56 to 203 billion kilowatt-hours across the country. That could equal a carbon emission cut of 60 to 211 million metric tons, depending on factors such as how dirty the energy of a particular utility was to begin with, before it started using less of it through smart grid systems.

A more recent one from the Utility Telecom Council (see Smart Grid News) says a generic one-million smart meter deployment with distribution automation and some distributed power generation sources could cut about 300,000 tons of carbon emissions from a utility's footprint (see Smart Grid's Low-Tech Savings: Fewer Truck Rolls).

But Angel noted that emissions reductions claims and methodologies to calculate them differ. "What's the common – or any – approach to what we can attribute to smart grid?" she asked the 140 or so participants on the call.

The EPA would also like to see a distinction between direct improvements from smart grid systems – say, efficiencies from utility-controlled distribution grid automation systems – and the indirect impacts of enabling more energy-saving technology in utility customer's homes and businesses, she said.

A measure of the direct impacts comes from EPRI, which says that hooking up distribution and transmission grids with smart control systems could save the country about 300 billion kilowatt-hours, or a little less than 10 percent of the country's generating capacity.

The indirect impacts of things like home energy management systems, on the other hand, are harder to preduct, since they deal with the complexities of how customers will react (see Utilities Mull Price Points, Policies for Home Energy Management).

Angel was quick to point out that EPA wasn't demanding such data, nor was it actively engaged in measuring the environmental impacts of smart grid systems at present.

Rather, she said, "I hope that that clearinghouse is something useful for all parties."