Engineering at Nebraska, Spring 2008
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Energy Monitoring on the Home Front

Together with OPPD,Nebraska Engineering studies devices to promote efficiencyX

Energy Monitoring Devices
photo: David Sockrider

Despite increased national attention on energy issues, people do not appear to be making significant strides toward conserving energy. A new initiative to be launched by the Omaha Public Power District (OPPD) and the University of Nebraska at Omaha (UNO) is attempting to change that. The Energy-Saving Potential (ESP) program was created to explore how the science and developed technology of residential and commercial energy conservation may be applied to achieve a substantial reduction in energy demand by individuals and small businesses.

One ESP funded project, "Energy Conservation and Behavior Change through Real-Time Energy Monitoring (RTM)" partners UNO and UNL's architectural engineering and construction programs. The RTM project seeks to determine to what extent displaying electricity use as it is being consumed (in both units of electricity and dollars and cents) influences sustainable behavior change regarding energy consumption and conservation, according to Patrick Wheeler, UNO's environmental advocate and principal investigator of the project.

According to Avery Schwer, associate professor of construction systems in Omaha, there is a great need to change consumers' energy consumption habits and behaviors, as well as to seek efficient energy delivery systems.

Dale Tiller, associate professor of architectural engineering, said the easiest way to monitor energy usage at the consumer level is via the monthly bill. However, he noted, "There isn't much timely information or specific details concerning the most costly times or what uses the most energy."

The study's objective, then, is to compare behavioral change and energy reduction as influenced by several commercial monitors to measure real-time consumption. Their hope: that more timely feedback on electricity usage will reduce residential energy consumption, thus lowering energy bills.

Denise Kuehn, a 1987 electrical engineering graduate from UNL who is overseeing the study at OPPD, said the study "Isn't about technical development of a new monitor, but behavior change for energy users."

For OPPD, which granted approximately $230,000 to the project in its first year, "providing sustainable behavioral change without creating huge inconveniences for our customers"Can not only save customers' money, but enable the company to reallocate its resources in other directions, said Kuehn.

The ESP project is also helping OPPD stay at the forefront of some "Early trending" Involving its customers in the energy consumption reduction process.

"Currently, there are a handful of companies in the U.S. and Canada working on projects similar to ours,"she said," but many are also in the early stages."she noted she had already spoken at several events concerning the university study.

As well as the team of faculty involved-including Moe Alahmad, assistant professor of architectural engineering; Dale Tiller, associate professor of architectural engineering; and two grad students- OPPD has provided staff support in the areas of rates, metering technology, call center training, and meter troubleshooting.

The Process
To begin the study, which kicked off in the spring of 2008, OPPD and the research team chose a geographic area in Omaha already being used for another pilot study. The fixed area network serving this area allows researchers to gather use information in 15-minute intervals, showing not only how much electricity was used, but when.

Approximately 2,000 invitations were sent to OPPD customers, with about 220 positive responses received. Ultimately, 150 households are currently involved in the project. Customers were assured that the study would not be used to raise electric bills and they would not be identified.

According to Alahmad, the research team evaluated seven monitors for such attributes as ease of set-up and operation, usefulness of data presented, aesthetics, accuracy of information, and the interface requirements. After careful review, two monitors - the Aztech In-Home Display and Blue Line Innovations Power Cost Monitor - were chosen.

The monitors were then divided into three groups of 50, with half of the Aztech in-home monitors programmed to display color changes according to times of day and half based on historical use of the home involved, Schwer said.

Approximately a dozen undergraduate and graduate students were hired to install the monitors from May to July, including at the homes of some research team members, OPPD staff and OPPD customers.

All of the monitors are fairly small and unobtrusive, Kuehn said, and are placed in the customers' kitchens or other high visibility areas for easy access.

"Each has its own strengths. There isn't really one that stands out as best, and they all have their own ideas and ways of monitoring information and usage," said Tiller.

"We understood the challenge: it takes a couple of months to really change behavior, but then, can that behavior be sustained?"

For the Aztech display, colors are used to show usage depending either on the time of day - green is off-peak, amber is mid-peak, and red is on-peak time (generally in the afternoon), or based on a percentage of historical summer use, where green represents the first 40%, amber from 40-60% and red anything above 60% (with the device resetting at midnight). The monitors show a numeric graphical display as well, including hourly usage in kilowatt hour (kWh) and dollars. Wireless technology is used to connect the monitors to smart electrical meters at the home sites.

Members of the energy monitor research team include: Josh Eiden, Denise Kuehn, Patrick Wheeler, Moe Alahmad, Avery Schwer, Steve Cross, Andrea WilkersonMembers of the energy monitor research team include: Josh Eiden, Denise Kuehn, Patrick Wheeler, Moe Alahmad, Avery Schwer, Steve Cross, Andrea Wilkerson

The Data While the ESP project initially was scheduled to collect data through the summer of 2008, the project has been extended for an additional calendar year.

"We understood the challenge: it takes a couple of months to really change behavior, but then, can that behavior be sustained? Otherwise, it won't be worth the investment that the customers make," Kuehn said.

Analysis of the study will begin this fall, noted Schwer, with survey instruments developed for gathering customer feedback, and processing usage data gathered from Itron (the smart meter manufacturer).

Kuehn is currently using both monitors in her home and said participating in the study has helped her become even more aware of peak energy times.

"I'm finding that the visual signals are really important. For example, if the same colors regularly appear at the same times of day, then we tend to ignore data."

Kuehn's nine-year-old son is also very interested in the study and has been carefully involved in watching the energy monitors. It's not too early to begin educating the next generation of energy consumers, Kuehn said, and OPPD hopes at some point to extend this information into grade schools through an educational component.