Can A Smart Home Save Energy?

This article first appeared on Efficiency Vermont's blog on October 26. 

The home automation market has taken off in recent years. Whether it’s smart thermostats, voice-activated assistants like Siri or Alexa, or smart lighting, new technologies are being developed quickly by both big industry players and small innovators. Home Energy Management System (HEMS) hubs, sometimes referred to as smart hubs, were among the first technologies to create an interconnected home ecosystem. HEMS hubs allow a variety of home automation devices, such as lighting and temperature control systems, to work together. A HEMS hub essentially serves as “mission control” for an entire home. At Efficiency Vermont, we’ve been actively exploring these technological advances as they evolve, recognizing that they may represent the next big step toward achieving major energy savings in homes and businesses, thus benefiting more Vermonters.

A pilot study for energy saving potential

In order to determine just how much energy these systems can save, we designed a pilot program to map, define, and measure the interactions of HEMS hubs and their connected devices. Efficiency Vermont staff selected a representative sample of homes to participate in the pilot study. Each participating home received five smart lightbulbs and a smart outlet, which were all certified to work together on the provided HEMS hub. With a few taps on a smartphone, users could remotely turn on or off whatever was plugged into the smart outlet (such as a fan), or remotely turn on or off, or dim, their smart lightbulbs. The participants were asked to install the devices on their own so we could assess the “out of the box” experience Vermonters would have if they bought the devices on a retail shelf. Throughout the duration of the study, we collected data on how much energy could be saved by smart lighting controlled with HEMS hubs, and which devices people were choosing to plug into smart outlets.

Some surprising results

We found that homeowners used the devices in ways that we hadn’t anticipated. For instance, smart lightbulbs allow homeowners to dim the bulb through their phone’s app, without a wall dimmer switch, and our research showed that this dimming happened a lot. In an average home, only about 10 percent of lamps are on dimmer switches; however, homeowners in this study chose to dim their bulbs 38 percent of the time, to varying light levels. Smart lightbulbs allow every connected bulb to be dimmed, and this new option may result in even more energy savings potential through reduced light levels. This represents a big opportunity for both the lighting market and energy efficiency programs. Our study did not provide any education, guidance, or suggestions for minimizing light use or scheduling lighting for maximum efficiency. If such guidance were provided, the energy savings may be even greater.

This study also monitored and catalogued what devices participants plugged into their smart outlets. At one point in the study, at least 67 percent of participants recorded having some sort of lighting device plugged in, such as a lamp or string lights. However, smart outlets allow plugged-in devices, like lamps, only to be turned on and off remotely, whereas smart lightbulbs enable users to dim the bulbs in addition to turning them on and off remotely. For that reason, our participants preferred to use the smart bulbs to control their lighting. Additional study is needed to determine the biggest energy savings opportunity provided by smart outlets.

We were pleased to see how enthusiastic and engaged the participants in this study were throughout the entire process. This showed us that Vermonters are motivated to achieve energy and cost savings with HEMS technology. Our findings indicate that smart homes represent a major opportunity for efficiency programs to engage with customers and potentially reduce energy use, benefiting both individual homeowners and ultimately the entire state.

What’s next for HEMS in Vermont

At Efficiency Vermont, we are keenly attentive to innovative products. We take an interactive, close look at new energy-related technologies, and pursue those that show the most promise for the state’s residents. This is one of the first studies to assess smart lighting and HEMS devices in real-world settings with a universal product, lightbulbs. I believe that this study has provided us with valuable insights into the future state of the smart home industry and the energy savings opportunities that exist there. We now also understand the moderate challenges homeowners may have in installing and using these devices. This knowledge can help Efficiency Vermont and other efficiency programs partner with manufacturers to improve the performance and functionality of HEMS devices. Our hope is that by engaging early, we can influence the optimization of smart home devices for energy efficiency.

Read the full report of this study to learn more about our findings, the savings potential, and where this research is leading us.

Lara Bonn is the Efficient Products Strategic Planning Manager at Efficiency Vermont. She is a regular contributor to their blog on topics relating to high efficiency products.