Users of Microsoft's Hohm online energy management service will be able to keep tabs on their household electricity usage in real time, on their computers and mobile phones, under a new partnership between the company and San Francisco-based Blue Line Innovations, which specializes in wireless devices for monitoring energy consumption.

Launching today, it's do-it-yourself meter reading, using technologies never imagined by those poor suckers forced to traipse into our backyards when we were kids. Microsoft describes the Blue Line partnership as part of its vision of a future in which every component of household energy consumption -- including appliances, electrical outlets, and even cars -- will connect to the Hohm system.

The underlying Hohm service remains free to use. But the additional Blue Line setup will require some upfront costs -- about $250 for a package that includes a sensor that attaches to the meter (pictured above), a wireless in-home energy monitoring device and a preconfigured WiFi gateway. The sensor works with about 90 percent of meters, digital and mechanical, Blue Line CEO Peter Porteous says.

Automatic real-time energy monitoring has been the top-requested feature from Hohm users, said Troy Batterberry, a Microsoft general manager. The idea is to give people the ability to watch trends in their energy usage and make adjustments on the fly -- such as turning off unneeded lights or electronics -- to reduce consumption.

Microsoft cites studies showing that people using monitoring devices save up to 15 percent in energy bills. "Real-time feedback makes it much easier to reduce your overall energy costs," Batterberry says.

Since the launch of the service last year, people have been able to enter information from their energy bills manually, or access data from selected utilities, including Seattle City Light, to analyze consumption.

The companies are hoping that the promise of energy cost savings will persuade consumers to make the initial investment.

Microsoft Hohm can be accessed as an online service on a variety of browsers and operating systems, but the Blue Line setup program requires a Windows machine.

What about privacy issues? Microsoft says it won't disclose any personally identifiable information that the Hohm system collects. Long term, the business model includes providing anonymous, aggregated data to utilities.

An energy consumption chart in Microsoft Hohm showing data pulled from a Blue Line PowerCost Monitor Sensor.