Green & Greener

Digital Monitor Can Help Cut Electric Bill

PowerCost Monitor ™ from Blue Line Innovations of Canada

Photo Credit: Blue Line Innovations

PowerCost Monitor ™ from Blue Line Innovations of Canada


Most of us think of home energy savings in terms of products, prices and percentages.

For instance: A compact fluorescent light bulb costs about five to 10 times as much as a standard incandescent bulb, it uses about 75 percent less energy, and it lasts eight to 10 times longer.

But you can also save energy and money simply by getting the right information.

The right information in this case means determining the amount of electricity used by all the equipment in your house. This can frequently be significantly reduced, saving money as well as energy.

The trick is getting the information. It sounds easy until you start to think about it. If you're like most homeowners, you have no idea how many kilowatt-hours you use a month, let alone which things use how much. Moreover, your electricity bill arrives four to eight weeks after the fact, so by then whatever you did to make those numbers go up or down is history.

In the past, trying to measure the power draw of different appliances was an exercise in frustration. You could get plug loads (the power draw of everything that plugs into an outlet), but you couldn't measure anything hard-wired (things with no outlet, such as ceiling lights) or anything on a 220-volt circuit, such as your water heater.

Digital monitors, which became available a few years ago, overcome those challenges. These handy devices, which receive a signal transmitted from a second piece of equipment attached to your electric meter, provide instant feedback on your electricity use and its cost. The monitors, which can be carried to any room in the house, do not indicate the power draw of a specific item. But you can easily figure it out by watching the numbers go up and down as you turn a light fixture or television on and off or stand by the refrigerator as it automatically switches on or off.

Pilot projects in the United States and Canada have shown that homeowners who used these devices quickly connected the dots between what they were doing or using, how much electricity was being used and how much it cost. Then they started to trim those kilowatt-hours and save money.

The monitors that the Ontario utility Hydro One gave to 400 households in 2004 provided an impressive amount of information. The homeowners could see their total electricity draw and its cost in real time, as well as running totals for the current billing period, and the predicted totals for the period, based on past use.

Homeowners could also see the amount of carbon dioxide they were contributing to the atmosphere in real time, as well as running and predicted totals for the billing period. (Carbon dioxide is the major component of the greenhouse gases that cause global warming. It is produced when fossil fuels are burned to generate electricity.)

The 400 households were followed for 12 to 18 months. Using the monitors, they reduced their electricity use by an average of 6.5 percent, said Dean Mountain, an economist at Ontario's MacMaster University who analyzed the data for Hydro One. Though not huge on a per-household basis, a reduction of this size in every household in Hydro One's Ontario service area would allow the utility to mothball two generating stations, Mountain said.

Which information affected household behavior the most?

Mountain said that the cost figures were the clear winners, although "moral suasion" and knowledge about carbon dioxide emissions influenced some people.

In two subsequent, smaller samples in British Columbia and Newfoundland, Mountain said the cost factor was even more compelling. In Newfoundland, where electricity costs are higher and incomes are lower, the households reduced their electricity use by 18 percent. In British Columbia, where electricity costs are lower, incomes are higher and the climate significantly milder, the reduction in electricity use was only 2.7 percent.

Danny Parker, principal research scientist at the Florida Solar Energy Center, conducted a similar two-year study of 17 households in central Florida for the U.S. Department of Energy’s Building America program. His results were similar to Hydro One's. With the information from wireless monitors, the households reduced their electricity use by an average of 7.7 percent. The motivations were also similar: Most households cared more about saving money than about saving the environment, Parker said.

Although Parker's sample was small, it did have an important advantage over the Canadian ones. He had contact with each household and learned in some detail what each did to reduce energy use.

The two households that saved the most electricity — 14.5 and 17.5 percent — were unusually motivated to make big changes. In one case, the family broke a major Florida habit: They stopped running their pool heater 10 to 12 hours a day and started using it only when they knew they would be swimming, which turned out to be only a few hours a week. They also replaced all their incandescent light bulbs with compact fluorescent ones and beefed up their attic insulation to lower their air-conditioning load.

In the other households, owners focused on smaller gestures such as "turning stuff off," Parker said, adding that although this sounds inconsequential, it does make a difference. "Fifty watts here, 100 watts there — all those little bits can add up quickly," he said.

In every house, Parker found that "turning stuff off" produced some unexpected "crazy thing." One family discovered a long-forgotten, institutional-type chilled water fountain in the far corner of their garage that used "much more electricity than a refrigerator," he said. In his own house, Parker discovered that his wife's pottery wheel motor had accidentally been left on for three months.

Although Parker has been studying household energy use for nearly 30 years, he encountered a few surprises. One was how much electricity is used by gas appliances: Gas dryers have electric starters, and newer gas stoves have electronic ignitions instead of pilot lights. Another discovery was the amount of electricity used in home entertainment areas, home offices and garages by appliances that were already turned off. Some items used nearly as much power in the "off" position as they did "on."

At Parker's suggestion, the homeowners added a power strip in these locations. Although a TiVo must be kept on, Parker pointed out that homeowners can still plug their television, speakers and DVD player into a power strip.

In Parker's house, which he monitored but did not include in his study, he reduced electricity use by 26 percent. Energy savings has become his “professional hobby,” but, he said, most homeowners who get a monitor are not likely to become this enthusiastic.

Katherine’s Experience

A month ago, I had never heard of a wireless digital readout monitor for home electricity use, but now that I have used one for several days, I would recommend it for every household.

These handy devices display the kind of information that makes you pay attention to your electricity consumption and how you can save money by reducing it.

I tested a PowerCost Monitor unit made by Blue Line Innovations of Canada  (www.bluelineinnovations.com). It is battery-powered and about the size of a TV remote. It displays the number of kilowatts our household is using and its cost in real time, the quantity of power in real time and compared with the last 24 hours and the last billing period, and a running total of kilowatt-hours consumed and dollars spent in the current billing period.

Even better, the monitor makes it easy to calculate the power draw for each of the many pieces of equipment we own and how much it is costing us. This has made us more conscientious about turning things off, which should lower our monthly bill. The monitor can display and calculate the figures for the tiered or time-of-use rates that many power utilities now charge.

The PowerCost Monitor unit used in several pilot studies in Canada displayed more information, including the amount of carbon dioxide a household was contributing to the atmosphere by its electricity use. But after the manufacturer found that most people are interested only in the data that will save them money, it no longer included other information.

The Energy Detective monitor, known as TED and made by Energy Inc. of Charleston, S.C., which I did not test, provides the same basic information. TED also displays the amount of power you have used that day, your projected total for the month and the voltage your utility is transmitting. (If this goes too low for too long, it can shorten the life of sensitive equipment such as a home computer.) TED has an alarm to alert you when the voltage has gone down.

TED, which is portable but must be plugged into an outlet, collects additional data that can be downloaded to a computer. This includes the carbon dioxide emissions associated with your electricity use and a breakdown of electricity used by your furnace, air conditioner, pool pump and hot water heater. TED can store 13 months of data. By the end of the year, the PowerCost Monitor will also have additional downloadable data.

TED is $145, and the PowerCost Monitor is $149.

January 2008