According to the Boston Globe, the venture capital arm of Royal Dutch Shell PLC is backing Sense, the startup that promises to give consumers detailed information about the power being gobbled up by every light, appliance, and electronic device plugged into their homes.

Sense, which employs about 18 people today, plans to grow to about 30 employees by the end of the year, chief executive Michael Phillips said. The company, which has been testing its device with a small number of early users, begins selling its $299 Internet-connected energy sensor to the general public today. Sense has raised nearly $20 million to date.

Several of Sense's key executives and engineers have rich backgrounds in digital speech processing, including work at Vlingo Corp., the creator of a pioneering virtual assistant for smartphones that was acquired by Burlington-based Nuance Inc. in 2011.

While that experience didn't directly translate into helping Sense analyze electricity use, there are some similarities. Distinguishing among a washing machine, an oven, and a basement light fixture that are all running at the same time is akin to picking out individual voices in a crowded room, Phillips said, because each device uses power in a different way.

'When the motor of your refrigerator turns on, it uses more power at the beginning because it's accelerating -- we call that a startup surge -- whereas a heating element is very constant,' he said. 'Something like a compact fluorescent light has a really short spike of energy that it draws at the beginning when it's charging up. For every single device, for the most part, there's some little signature like this that lets us know what it is, and what it's doing.'

Sense said it can uncover those hidden patterns with its device, which weighs about a half-pound and is roughly the size of two large iPhones on top of one another. The box is attached to the home's main electric panel and measures the electric pulses running through the system, roughly a million times each second. It sends that data over a wireless Internet connection to the company's online software, which performs another level of data analysis. That's where each device's 'fingerprint' is revealed, Phillips said.

Sense said its software will allow consumers to draw some interesting insights from the energy use around their home -- detecting when the kids arrive home from school and start flipping on the lights or monitoring how long the TV has been on during a given week.

Eventually, however, Phillips said the device could be used to connect with 'smart home' devices that let each appliance and light fixture connect to the Internet, possibly serving as a central hub for controlling separate devices.