Google announced a new service on Tuesday that helps consumers track their personal electricity usage, and could help lower a household's electricity bill as much as $180 a year.

PowerMeter -- a free Web service that's available as a widget on iGoogle -- will be offered by Google Inc.'s philanthropic arm to let consumers see in real time how much energy is being used in their house or business as it is consumed.

We believe that detailed data on your personal energy use belongs to you, and should be available in an open standard, non-proprietary format, Ed Lu of Google's engineering team, wrote in a blog post.

You should control who gets to see your data, and you should be free to choose from a wide range of services to help you understand it and benefit from it, he added.

Based on studies that show that home-energy-use information changes behavior and saves 5 to 15 percent of electricity, Google said it estimates a typical household's $1,200-a-year electricity bill could be cut by $60 to $180.

The smart meters differ from regular meters in the sense that they can provide detailed information about usage rates in real time, allowing consumers to make smarter decisions about when to leave the lights on, when to do their laundry or when to switch off a heavy energy-consuming product.

The application is currently being beta tested internally by Googlers and will stay that way as Google tries to build partnerships with utilities and independent device manufacturers.