Communicating Thermostats for Residential Time-of-Use Rates: They Do Make a Difference

Panel: Human and Social Dimensions of Energy Use: Trends and their Implications

Authors:
Mary Klos, Summit Blue Consulting, LLC
Jeff Erickson, Summit Blue Consulting, LLC
Elaine Bryant, Public Service Electric and Gas Company
Susan Lacey Ringhof, Public Service Electric and Gas Company

Abstract

Public Service Electric and Gas Company (PSE&G) recently completed a residential demand response pilot program to understand how customers react to price signals, and to test customer reaction to the opportunity to conserve when power is in peak demand. The pilot utilized two-way communications to transfer energy pricing and interval consumption data to and from the customer meter and allowed PSE&G to test and measure customer response to various pricing signals under various weather and price conditions. They provided communicating thermostats to one-half of the participants in their pilot to test the influence of technology enabled response. The pilot tested Time of Use (TOU) rates and Critical Peak Pricing (CPP) rates.

Customers with the enabling technology showed greater reductions in summer peak day demand, both in response to the daily TOU rates and the special CPP events. Technology enhanced customers reduced their average hourly demand during the 1:00 p.m. to 6:00 p.m. period by 21% (0.59 kW) in response to the TOU on-peak rate, and they reduced their demand by an additional 26% (0.74 kW) if a CPP event was called. This is a total reduction of 47% (1.33 kW). Compare this to impacts achieved by customers with central air-conditioning that were on the same rates but only received informational materials. They reduced their average hourly demand during the 1:00 p.m. to 6:00 p.m. period by 3% (0.07 kW) in response to the TOU onpeak rate, and then they reduced their demand by an additional 14% (0.36 kW) if a CPP event was called. This showed that the enabling technology helped customers double their CPP response and increase their daily on-peak TOU response seven-fold.

While the major finding of this study is that technology enabled customers are able to create substantially greater load reductions during peak hours for both TOU on-peak periods and CPP events, a look at energy savings throughout the year brings a secondary finding to light. Customers who only received information created greater year-round energy savings on a percentage basis. It is hypothesized that their need to change behavioral energy use patterns during the summer to benefit from the TOU and CPP rates raised their energy consciousness. That new energy consciousness became a habit that they continued throughout the year. Technology enabled customers did not create similar behavioral habits.