An application released on Tuesday plugs into the power of Facebook to make saving energy an online community affair.

The social networking colossus worked with the Natural Resources Defense Council and energy information software specialty firm Opower to launch the mini-program with an initial reach of more than 20 million US households.

The application -- available online at social.opower.com -- lets people monitor home energy use by connecting with local power companies using Facebook accounts and then share progress toward conservation goals.

An array of 16 utility companies have signed on for the program, which is intent on expanding.

"The enthusiasm we're seeing from people who are excited about getting better context about their energy use, and share or even brag about their energy efficiency within their social networks is inspiring," said Opower chief executive Dan Yates.

"It demonstrates a shift within the industry for how people expect to interact with their utility."

The application takes advantage of smart grid capabilities at public utility companies and then lets friends at Facebook compare energy frugality and even share tips or challenge one another to power-saving competitions.

"Facebook was designed to enable people to connect, share and multiply their impact," said Marcy Scott Lynn of Facebook's sustainability team.

"This app is a powerful, easily accessible way for people on Facebook to do just that, inspiring conversations about really important topics -- energy and the environment -- that might not otherwise have taken place."

If every US household cut energy use by one percent, it would lop $1.6 billion a year from the country's overall energy bill, according to NRDC attorney Brandi Colander.

The savings was equated to disconnecting 1.2 million US homes from the US power grid.

"This important tool will enhance energy literacy, making our daily energy choices more transparent and empower people to make smarter, more economical decisions," Colander concluded.