Powerhouse Dynamics has released a free iPhone app for its eMonitor circuit-level energy monitoring system. The iPhone app gives you a quick look at what electricity your house is using now, the top circuits using electricity, and how many watts they’re using—as well as overall usage that day, week and month—and costs in the last month per circuit. It’s a pretty basic rendition of the eMonitor’s web-based interface, and could be helpful to check while you’re on the road or when the kids come home and fire up the Xbox instead of doing their homework.

The app also updates your current energy use in a timely fashion—as the eMonitor updates about every minute. My own iPhone app was a bit behind the web site, but that’s no biggie.

Of course, you need the eMonitor ($700 for 24 circuits plus a $249 two-year subscription) to enjoy the iPhone app.

My feeling is that both the apps and the web-based eMonitor interface will keep improving over time, by offering more and more features.

From the time I have been using an eMonitor since mid-August, Powerhouse Dynamics has added a Phantom Power widget to the web interface. That tells you how much electricity is being used by those circuits that are always drawing some power. There’s also a “Is Solar Right for Me?” calculator that estimates the cost of a solar photovoltaic (PV) system, depending on where you are located, your electricity use, and what rebates or incentives are available to you. (The eMonitor can also monitor solar electricity production.) The solar checker has a slider so you can determine the costs of a PV system producing different percentages of your power.

You can also use Google’s PowerMeter with the eMonitor. Google’s online energy monitoring software reports on your home’s total electricity usage, by day, week, or month, and will tell you how efficient you are compared to other homes of your size. It’s a pretty basic interface, though I prefer the eMonitor’s more graphical and circuit-level interface to dig deeper into my electricity use.

You can see my initial review of the eMonitor for Electronic House here, or check out my four-month review here, which also features an audio interview with Powerhouse Dynamics’ CEO Martin Flusberg.

Steven Castle - Contributing Writer

Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates.