Energy Savings Enabled By Smart Devices

Jessica Xu
November 5, 2015

Submitted as coursework for PH240, Stanford University, Fall 2015


Fig. 1: The "Internet of Things" connects the world. (Source: Wikimedia Commons)

In recent years, the term "Internet of Things" has become the new buzzword. Taking a look at Figure 1, we see that the "Internet of Things" connects the world. As we gather and store more data about individuals and their interactions with the computer and their surroundings, we've come to find a system that enhances our understanding of these relationships. This is the three-way relationship between data, physical objects, and the Internet. As we develop and introduce more complex tools to the world, we are able to solve old problems with new creative solutions.

The Smart Grid

One of the most intriguing aspects that Internet of Things brings is the concept of the smart Grid. The smart grid is composed of many segments of the electric value chain and provides energy-saving and carbon-reduction mechanisms. For example, the smart grid enhances customer service through continuous commissioning/proactive maintenance, improves operational efficiency through reduced line losses and voltage control, enhances demand response and load control by saving energy through peak demand reductions, and transforms customer energy user behavior by providing direct feedback to consumers of energy usage via display devices. These mechanism have become integral to saving energy which as a result reduces carbon emissions. According to the Electric Power Research Institute, efficiencies enabled by smart grid technologies could bring about 56-203 billion KWh of energy savings and reduce 60-211 million metric tons of CO2 emissions per year in 2030. [1] One aspect of the smart grid I will be focusing on is the use of smart devices in smart home. Smart homes are like your average homes but decorated with smart devices. These devices collect user data and provide a personalized experience with the technology. In this paper, I will describe the effects of smart homes and smart energy through such use cases as connected homes and smart metering on energy consumption.

Fig. 2: The Nest Smart Thermostat. (Courtesy of Nest Labs)

The Smart Thermostat

One of the most common devices found in the home is the thermostat so appropriately, the most important device in a smart home is the smart thermostat. See Figure 2 for an example of the Nest Smart Thermostat. In a study on how smart thermostats can save energy in the home, the researchers compared the costs of using traditional thermostats versus the costs of using smart thermostats. In the research, they use cheap and simple sensing technology to detect occupancy and sleep patterns in the home and how to use these patterns to know when to turn on or off the home's heating, ventilation and cooling system. In other words, the researchers created their own version of a smart thermostat. Unsurprisingly, after deploying sensors in 8 homes, the researches found that these smart thermostats achieved a 28% energy saving on average, at a cost of about $25 in sensors. In comparison, the commercially-available thermostats that use similar sensors only saves 6.8% energy on average and actually increases energy consumption in 4 of the 8 households. [2]

The Smart Meter

Fig. 3: An example of a Smart Meter. (Source: Wikimedia Commons)

Another important, smart tool used to optimize energy consumption is the smart meter. See Figure 3 for an example of a smart meter. These smart meters provide not only homeowners but also commercial and industrial firms a synopsis of their energy usage and the real-time costs of providing it. For example, if consumers purchase or are provided with enabling technologies that respond to the smart meter like a smart thermostat, the smart meter can turn off the air conditioner when prices are high in a demand-response program. The smart meter can even have Direct Load Control capabilities which would let the utility exert remote control over energy use by turning on or off certain appliances. This is generally used to reduce peak-time load or disconnect after exceeding a pre-defined or pre-paid budget. [3] According to a study by the Brattle Group which analyzes dynamic pricing programs that shift peak time consumptions of energy to off-peak hours through smart metering across residential, commercial and industrial sectors, metering infrastructure has the potential to reduce peak demand by 5%, assuming 43% of customers are in each sector. Auto-DR programs enable customers to pre-program load reduction strategies into smart devices like the smart thermostat. Once programmed, load is then automatically reduced based on communication signals from the utility without the mandatory need for any further customer intervention. To estimate the potential energy savings associated with decreases in peak-time demand, the 5% Brattle value is multiplied by the peak demand forecast for 2030 of 1.14 billion kW. The results show that the ratio of energy savings to peak demand reduction achieve by these automated demand response programs is 65 kWh per KW, with a total savings of up to 3.7 billion kWh. [1]


The benefits of the smart grid on energy consumption are expansive, but the technicalities may turn the layman away. However, with the simple design and ease-of-use that innovators have imagined for devices today, like the smart thermostat and the smart meter, we, as a society, will no longer have an excuse for wasting energy. Our innovations break down many barriers towards becoming eco-conscious and encourage us as individuals to care about our total energy costs. The smart thermostat and the smart meter are just the tip of the iceberg in terms of the total benefit smart devices can provide us. With more time, even better and even more smart devices can be created, as we tirelessly work towards the goal of both saving money for the household and reducing energy consumption for our planet.

© Jessica Xu. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] O. Siddiqui, "The Green Grid," Electric Power Research Institiute, Technical Update 1016905, June 2008.

[2] J. Lu et al., "The Smart Thermostat: Using Occupancy Sensors to Save Energy in Homes," Association for Computing Machinery, ACM 1870004, Proc. 8th ACM Conference on Embedded Networked Sensor Systems, 3 Nov 10, p. 211.

[3] T. Krishnamurti et al., "Preparing For Smart Grid Technologies: A Behavioral Decision Research Approach to Understanding Consumer Expectations About Smart Meters," Energy Policy 41, 790 (2012).