One way to save energy is to be fully aware of how much you're using. That's the mission of The Energy Detective 5000, otherwise known as TED 5000. Connect a couple of sensors to your main power switch box, plug the powerline gateway into an electrical outlet, connect it to your network, and suddenly you can access a graphical interface showing you exactly how many kilowatts you're using over days, weeks and months. We hooked up the TED 5000 in our Midwest Test Facility, and it turns out we're not using as much energy as we thought.

We're not comfortable working around lethal voltages, so we hired an electrician to install the two sensors (called current transformers, or CTs) into our main power box. Just like the instructions predicted, it took barely 15 minutes to accomplish this easy task, and then all we had to do was plug the gateway receiver into an outlet, and we were good to go. That gateway was finicky about which outlet we plugged it into — it wasn't able to receive TED's signals from many of the outlets in our facility — but we found one that was near an Ethernet port that was suitable, with the gateway telling us all was well by blinking a green light on its side. We contacted the gateway to our gigabit Ethernet network, and all was ready.

Navigating to TED's website, we next experienced the minor thrill of "Footprints," a Java-based web app. Compatible with Windows, Mac and Linux, it shows exactly how much power you're using in real time. It gathers this information and accumulates it, and even lets you specify your power company's electricity rates so it can notify of how much you're spending, right down to the minute.

Google has also gotten into the act with its Google PowerMeter, a web-based widget that interfaces with the Ted 5000 and shows you pretty graphs that also spell out exactly how much power you're using. None of these graphics can show you exactly which devices are using all the power in your house — but you can unplug your gadgets one at a time and instantly see the result. This is especially easy when you carry around the optional ($40) rechargeable remote display, giving you real-time readings of your power usage.

TED 5000 is not perfect. Its gateway lost its signal a couple of times while we were testing it, probably the fault of the location we picked to plug it in. But that location was the only place we have that's near an Ethernet port and worked at all. Perhaps because of that, it gave us readings that seemed a bit low. Or maybe we're just saving a lot of energy lately. However, our power bills around here are regularly $150 or higher, and TED predicts this month's bill will be $88. We wish. We'll continue to tweak it, hoping for better accuracy. However, if this system is intended for consumers, it should be completely fail-safe out of the box.

Summing up, we like the TED 5000, despite its slight drawbacks. It's useful — just like when you're trying to lose weight, it helps to know exactly how much energy you're using. The idea is that you might not be such an energy hog if you know how much you are consuming. However, we think it would take a long time and a lot of energy savings for TED 5000 to pay back its $240 price. Never mind that, though, the Ted 5000 works as advertised, and we had a great time playing with it.

The Energy Detective 5000