Your neighbor used how much electricity?

Peco Energy Co. has stepped up a program comparing individual customers' energy usage with their neighbors', a social experiment aimed at nudging consumers to keep up with the Joneses and cut their power use.

This summer, the Philadelphia utility issued home energy reports to 400,000 of its 1.6 million customers, individually charting their electricity consumption compared with the average of similar households nearby. Peco says it will send the reports every two months for two years.

It plans to observe the behavior of customers who receive the reports to see whether they reduce usage or enroll in the utility's efficiency programs, which offer energy audits and rebates for new high-efficiency appliances and lighting.

"We want to understand whether this type of program can drive customers to take energy-efficiency measures, and if it does, whether to expand it to our other customers," said Ben Armstrong, a Peco spokesman.

Studies of similar behavior-modification programs have shown that customers reduced power usage about 2 percent in response to the mailings. Two percent may not sound like much, but in an industry that has historically focused only on growth, any reduction is significant.

Peco began providing the reports to a small number of customers in 2013, and added 260,000 this year, including 60,000 customers enrolled in a program that allows Peco to curtail their air conditioners during peak hours. Other than enrollees in the Smart AC Saver effort, the customers are randomly selected, Armstrong said.

The program is part of Peco's five-year, $427 million energy-efficiency and conservation plan, approved by the Pennsylvania Public Utility Commission this year.

The PUC says Peco needs to cut about two million megawatt hours and to reduce its peak demand by 161 megawatts by 2021. The measures are required to comply with a 2008 state law known as Act 129, which imposes energy-reduction targets on all large state utilities.

Behavioral economists know that humans are more likely to modify their practices when they are held up to a "social norm." Peco, in its PUC filing, said it was "offering to leverage the power of social norming to drive persistent energy savings through smart energy practices."

Not everyone has welcomed Peco's information.

Daniel Katzenberg, an Elkins Park resident who takes pride in his stingy energy habits, said he was irked when Peco's report indicated that his household's consumption trended above average in June.

"I'm one of those people who focus on not consuming too much, to the point of annoying people," he said. "So this was surprising.

"I don't have confidence in the data," said Katzenberg, who works in the University of Pennsylvania's budget office and says he has "a born skepticism" of numbers. "Does that mean it's not a good cause? I definitely support energy conservation."

Katzenberg says he knows his household consumes less than the 700-kilowatt-hour monthly average for all Peco residential customers. But Peco's home energy report compares his usage with a smaller subset, about 100 similar dwellings less than a quarter-mile from his home.

Peco's report also cites the usage of the top 20 percent of Katzenberg's neighbors, saying he used about 65 percent more power than his most efficient neighbors, costing him about $454 more a year.

"These efficient neighbors, I want to meet them," he said. "Maybe they're vacant homes."

Peco's Armstrong says the household information is derived from public databases, supplemented by personal data customers have entered into the utility's system if they took an online audit. He said the leaner households may have more efficient heating or air-conditioning systems, or more energy-efficient appliances.

The data comparisons are done by Opower Inc., a company that works with about 100 utility companies, including Peco's parent company, Exelon. Opower says that its "big data platform stores and analyzes over 600 billion meter reads from 60 million utility end customers." It was acquired this year by the software giant Oracle Corp.

Armstrong said the data Peco collects are secure and not resold. Customers can opt out if they don't want to receive the reports.

The comparative-usage data are available online for all customers, regardless of whether they receive the mailed reports.

Customers can log in to their accounts at Peco.com and access the information under "View My Usage."

amaykuth@phillynews.com

215-854-2947 @maykuth