Smart Thermostat Study
The purpose of the Study is to understand the effect of this emerging technology in residential homes within certain hot and cold climate zones in PG&E’s service territory. The two focus areas for the study are an estimation of the energy savings for participating households, and an assessment of the participants’ experience while taking part in the study. The Study used a randomized encouragement design (RED) approach in which several thousand homes were randomly assigned to the encouraged group, all of whom were offered a free, directly-installed smart thermostat, and two thousand similar homes were randomly assigned to a control group, none of whom were offered a thermostat. Three different brands of thermostats were tested in the study; the goal was to install 1,000 of each type of thermostat in participants’ homes. A total of 2,207 thermostats were installed. The first year results include analysis of a winter heating season and a summer cooling seaon. All three thermostats achieved annual electric savings ranging from 4-5%. One of the thermostats tested also achieved annual gas savings.
In Q1 2017 PG&E plans to update the report with the results of an analysis of operational data gathered from the thermostats during the first year, such as runtime and setpoints, and again in Q4 of 2017 with analysis of both energy usage and operational data gathered during the 2nd year, and additionally the results of a customer survey that will be performed in the same period.