While most homeowners have a vague idea of how much they pay for utilities each month, few are aware of just how much electricity they use on a daily or weekly basis. Nor do they know which appliances contribute the most to their electricity bill or exactly when most of the electricity in their home is being consumed. Homeowners seeking to fill in this knowledge gap can now turn to home energy monitors, which provide real-time information about their electricity usage.

Becoming more aware of energy usage is the first step consumers need to take if they are to become smarter, greener homeowners, said, Hugh A. Joyce, president, James River Air Conditioning, Richmond, Va. “We believe that what gets measured gets done. If there’s a radar gun on your car all the time, you won’t speed. If you measure the performance of your technicians and post it, they tend to perform better. And if you measure how much juice you’re using in your home, you tend to figure out ways to use less.”

While there are many different types of home energy monitors available, Joyce likes those that can be linked to Google PowerMeter, which is a free energy monitoring tool that enables customers to view their energy consumption online or via a Smartphone. By monitoring electricity use - and modifying their behavior - Joyce noted that most homeowners should be able to recoup the cost of their energy monitor in one or two years.

DRIVING DOWN ENERGY USE

Joyce has offered customers home energy monitors coupled with Google PowerMeter for about six months as a way to encourage customers to become smarter energy users. “What we love about Google PowerMeter is that wherever they are, homeowners can always check their home’s energy usage. It provides hourly, daily, weekly, and monthly energy-efficiency ratings, but even more importantly, Google looks at the house all the time and creates an ‘always-on’ graph.”

The always-on graph reports the phantom load that is always on in a house, such as refrigerators and computers. The always-on load is where the rubber meets the road in energy savings, noted Joyce, as this is an area that can easily be modified by homeowners.

“By monitoring peak loads and the always-on numbers through Google, homeowners can tweak their houses to drive those two numbers lower,” said Joyce. “Google PowerMeter actually walks customers through how to drive their power usage to its lowest level, then it’s possible to share that data with friends and family. The collaborative effect of sharing the data is very powerful because it can incentivize others to be smart about energy use in a non-punitive way.”

On the hardware side, Joyce offers The Energy Detective (TED) home monitor because of its price point, its ease of installation, and its ability to interface with Google PowerMeter. “TED has developed some very good algorithms and approaches to monitoring the watts that a house is pulling at any given time. We are very comfortable with the product, and it’s worked great for us,” he noted.

TED has three main components - the measuring transmitting unit (MTU)/current transformers (CT) set, the gateway, and the optional wireless display. The two CTs clamp around the two main incoming conductors into the breaker panel and are connected to an MTU, which is a small black plastic box that is mounted into the breaker panel. The MTU is wired into both an A and B phase breaker and sends a power line carrier (PLC) signal to the gateway, which is a black box that plugs into any outlet. The gateway picks up the PLC signal from the MTU and can communicate via Zigbee wireless (to the wireless display) or Ethernet (to an existing Internet router or directly to a computer).

Customers can personalize TED by entering in their specific utility rates, and creating load profiles for specific appliances in their home. A load profile works by recognizing the unique start-up signature load of large appliances (such as a HVAC, hot water heater, pool pump, etc.).

“TED users can create a load profile for up to five appliances, including their HVAC, by using the Load Profile Wizard on the Footprints software,” said Melissa Lacas, director of marketing, Energy Inc. (manufacturers of TED), Charleston, S.C. “Many third-party studies have shown that using real-time electricity monitors reduces electricity bills by an average of 10 to 15 percent.”

MAKING SMART DECISIONS

The Envi home energy monitor from PowerSave Inc. also uses Google PowerMeter to help customers drive down energy usage. The basic Envi monitor consists of a screen device that displays real-time energy usage along with a transmitter and clamps that are installed around the electric cables in the breaker panel.

“The clamps sense the magnetic field around the cables that is produced because of the energy going through it. That information is then sent, via the wireless transmitter, directly to the display,” said Robin Pearl, general manager, PowerSave Inc., Fort Lauderdale, Fla.

The Envi monitor is capable of measuring up to 10 devices and provides detailed information about energy patterns. When coupled with Google PowerMeter, homeowners can receive weekly e-mails detailing whether energy use is up or down. This information is critical in allowing homeowners to make smart decisions about their energy use.

“When you go to the supermarket, you don’t just throw stuff in your shopping cart, walk out the door, and expect to get a bill from Wal-Mart at the end of the month,” said Pearl. “Instead, you look at the prices of products and decide which ones you want to buy. We make decisions every single day based on price, and with the energy usage in our home, we do not have a clue.”

A home energy monitor is a tool that can be used by homeowners to make smart decisions about their energy usage. For HVAC contractors, monitors can be a profitable accessory to sell, or they can be included as part of a package. “Many of our contractor customers include one of our energy monitors when they install a new heating or cooling system,” said Pearl. “They install the monitor before the new system goes in, so customers can see how much energy the old system is using compared to the new one. This gives confidence to the customer that the contractor really knows what he’s talking about.”

Joyce currently sells the home energy monitor as a separate accessory, but he is considering offering it as part of a whole-house capacitor/surge protector package. “Customers love the energy monitor - it’s really the ultimate in green. You measure what you’re using, drive it down, and make what you have work better. We’re seeing very positive results.”

Publication date: 12/13/2010