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PlotWatt Web app spots home energy hogs

Start-up can track big power-consuming appliances in the home, a feature that could make energy monitors better at pinpointing energy savings.

Martin LaMonica Former Staff writer, CNET News
Martin LaMonica is a senior writer covering green tech and cutting-edge technologies. He joined CNET in 2002 to cover enterprise IT and Web development and was previously executive editor of IT publication InfoWorld.
Martin LaMonica
3 min read

PlotWatt's software doesn't just read electricity meter information and post it online. It takes a building's energy pulse to find out what's going on inside.

Like many other building energy start-ups, the North Carolina-based company is developing a system to provide recommendations on how to improve efficiency based on meter information. To build a profile of a building's energy use, PlotWatt's cloud-based software parses a home's power signal to tell consumers where most of their energy goes.

The software detects differences in power consumption patterns to isolate large appliances, such as air conditioners and freezers. Once consumers get a good read on those big energy consumers, they can make adjustments, such as changing the schedule on the pool pump or programmable thermostat.

"You can imagine the energy trace from your refrigerator is distinct from your dryer. We capitalize on those differences," said Luke Fishback, the CEO and company founder. "It's a fun pattern-recognition problem."

Recognizing the electronic signature of different appliances may become a more common feature for energy monitors, as smart-grid companies try to develop products which appeal to consumer and business customers.

Intel's home energy management research group earlier this year said it is working on a wireless plug which monitors and identifies big energy consumers in a home. Another popular home energy-monitoring device maker is expected to introduce a similar feature this year, according to an industry executive.

Knowing only the top energy producers in a home or office building doesn't provide the level of detail high-end home energy management systems offer already. But isolating energy hogs with a relatively simple and cheap approach is effective for saving energy, says Fishback.

Where did your energy go last week? Recognizing the electronic signature of large appliances, the PlotWatt application can identify large energy consumers.
Where did your energy go last week? Recognizing the electronic signature of large appliances, the PlotWatt application can identify large energy consumers. PlotWatt

"We just focus on remediable waste. We look at where there are levers for measurably impacting people's energy bills," he said. "We can't disaggregate things like cell phones, but that's not an interesting problem--you unplug them and you save $2 a year."

Right now, PlotWatt's free online application requires either a smart meter or a whole-home energy monitor which uses a home broadband connection to send data online. Although the product is available to consumers, the company is initially targeting small businesses, such as retail stores and restaurants, for a paid service.

Hardware gateways
There are already a handful of whole-house energy monitors, such as the PowerCost Monitor, the Energy Detective, and Wattvision. These products, which can feed information to PlotWatt, focus mostly on displaying real-time electricity use and historical usage data.

At PlotWatt, Fishback is seeking to create a user interface that makes energy information interesting to more than just "energy geeks." Part of that is translating kilowatts and kilowatt-hours into dollars and cents. For instance, the application will project how much a consumer will spend on air conditioning for a month.

To make the software compelling to a broader audience, the small start-up, which received a $100,000 grant from General Electric and $1 million in funding earlier this year, is working on a recommendation system.

By analyzing data specific to a home, PlotWatt expects it can create targeted recommendations and alert customers to faulty equipment. For instance, it could project savings of changing the thermostat setting or tell a consumer that an air conditioner likely has a mechanical problem based on usage patterns.

There are a few other companies creating cloud-based services around building energy, including EnergyHub and EcoFactor. The goal is to provide recommendations that go beyond generic home efficiency tips.

Related links
EnergyHub makes beeline to consumer smart grid
Microsoft kills Hohm Energy app
Smart thermostat links to cloud for energy savings

For now, though, Fishback thinks the most promising route to making money is the small business market. In his own home, PlotWatt software allowed him to dramatically cut monthly electricity bills though he admits that he's an "early adopter" type.

It's beta testing the service with business customers now. "One of the reasons we like small business with multiple locations is that it's really easy to justify the fairly small cost of hardware when the savings are so big," Fishback said. "Whereas in residential sometimes it takes months for the hardware to pay for itself."