Imagine a device that, when plugged into the wall, could read the power usage of every appliance, television, computer, air conditioning unit and light bulb in the home. Two separate contenders — electronics giant Belkin and stealthy Rutgers spinout PowerMap (pdf) — say they have the technologies to make that scenario a reality. And while there are differences between the two, the important thing to note is that this “one plug to read the rest” approach could disrupt the existing field of home energy management.
Most existing home energy management systems fall into two broad categories. Cheap ones — or free, in the case of Google PowerMeter or Microsoft Hohm — use electrical meters to gather their power information. Those give only entire-household energy usage, not reads on individual appliances. Systems that can actually do the latter need dozens of smart plugs for each individual appliance, or a circuit-panel reader installed by an electrician — and those can cost hundreds of dollars.
A single power socket-mounted device that could read multiple devices, on the other hand, could be a lot cheaper, better meeting expectations that consumers don’t want to pay much more than $50 to $100 for technology to manage their own energy.
So how can such a device yield enough information to measure specific appliances? In PowerMap’s case, it’s by reading the sine wave signature of the alternating current that zings around a home. Power Map CEO and co-founder Rick Mammone’s background is in speech recognition technology. In an interview last week, he told me that compared to differentiating people’s voices by the slight variations in sound waves, telling your washing machine from your dishwasher is much simpler.
Unlike decades-old, low-frequency powerline sensing technology, Power Map uses higher frequencies like those used by the HomePlug power line carrier specification. That allows Power Map to measure the complex impedance of a device, which can tell when an appliance needs to be repaired and replaced, as well as how much power it’s using. Once Power Map’s meter is plugged in, it spends about 20 hours listening to a household’s current and to hear how appliances and devices “sound” when they turn on and off. That’s enough to give an identity to everything that’s plugged in at the time — and from that point on, it can measure how much power each appliance or system is using, all for the cost of a single plug-in meter.
Belkin’s technology differs from Power Map’s in that it measures the voltage of the household electricity, rather than the frequency. Belkin got the technology from Zensi, a tiny startup it acquired in April. Ashton, co-founder and CEO of Zensi and general manager of Belkin’s Conserve line of energy efficiency gear, told me this week that it makes sense of the noise on a household current via cloud-based algorithms originally developed for facial recognition software. With the algorithms it can individuate each load, down to each single light bulb. It also tracks performance and efficiency of appliances to see if they’re starting to malfunction.
The one thing both Belkin and Power Map’s systems lack is any way to control devices’ power use — but both companies say they’re looking at ways to do that as well. Belkin hasn’t said how it plans to bring its “one plug reads all” technology to market, but it has a huge line of energy conservation products and utility industry inroads. PowerMap has yet to disclose how much money it’s raised or how much it’s seeking to bring its product to market. But it has set a $50 price tag for its plug-in meter.
It will be interesting to see how these cheap-and-smart offerings compete in the already crowded home energy management landscape. It will also be interesting to see if competitors emerge, either from garages or the labs of Intel, which has been working on a one-plug measurement device for some years.