February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 1 /29 Temperature Effects on Residential Electric Price Response Karen Herter February 23, 2006

Karen Herter, LBL/CEC/UCB-ERG 2 /29 Overview Questions to Answer  Do critical peak pricing (CPP) tariffs reduce peak demand?  How does local climate affect residential customer response to CPP events? Motivation – why CPP?  Economics: better link wholesale and retail markets  Reliability: respond to local or system emergencies  Customer service: the California Statewide Pricing Pilot (SPP) participants liked the experimental CPP rates

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 3 /29 Economics: California Power Costs, 2000 Avg.

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 4 /29 Reliability: still working on response time & technology issues

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 5 /29 Customer Service: SPP Post-pilot Survey (N=196) Why? Save money 58% Control/save energy 17% I like it 12% Why Not? Need more time to decide 58% Too much hassle 22% 23% 77% New Rate Old Rate 25% 62% Should it be offered to other customers? Definitely Probably 13% Definitely/ probably not Why? Save energy 19% Save money 17% It’s good/we like it 15% Conservation awareness 13% Chance to participate 12% Control/manage energy use 5% Would you stay on the new rate? Source: Momentum 2004 (only about 50% actually did stay on the CPP rate once the pilot participation incentive was removed)

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 6 /29 I. Background

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 7 /29 CA Statewide Pricing Pilot, Cooperative effort  CEC, CPUC joint proceeding  PG&E, SCE and SDG&E joint pilot Pilot design  ~2000 residential customers  3 new revenue-neutral rates  15-minute load data Data stratification  By climate zone (4)  By building/usage type (3)  Bayesian sampling determined sample sizes for each of 12 strata

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 8 /29 Experimental CPP Tariff (approximate average values) $ Hour of the day $0.10 $0.20 $0.60 critical peak price peak price off-peak price

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 9 /29 CA System Loads as a function of Temperature

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 10 /29 Two Groups Considered in this Analysis Manual Group  CPP rate  Information on how to respond PCT Group  CPP rate  Information on how to respond  Programmable communicating thermostat (PCT) programmed to automatically respond to CPP signals

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 11 /29 II. Manual Response (no automated controls)

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 12 /29 Data Analysis for Manual Group Divide hourly data (24-hour load shapes)  5°F peak temperature bins  Normal/critical days Average daily load shapes across days, by customer   2 load shapes per customer - one normal and one critical Average customer load shapes across customers, by stratum   2 load shapes per stratum - one normal and one critical Average stratum load shapes across strata, weighted by population and sample share   2 final load shapes - one normal and one critical - representing the average response of SPP participants exposed to the given temperature and weighted to reflect the CA population

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 13 /29 For those who had coffee this morning… Response ij = (Hourly Usage on Critical Days) - (Hourly Usage on Normal Days) =

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 14 /29 Manual Response, by 5°F Temperature Bin

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 15 /29 Manual Group: Diurnal Load Shapes, °F (Hot) Average Response = -13%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 16 /29 Manual Group: Diurnal Load Shapes, 60-95°F (Mild) Average Response = -4%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 17 /29 Manual Group: Diurnal Load Shapes, 50-60°F (Cold) Average Response = -9%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 18 /29 Manual Response as a Fraction of Normal Load

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 19 /29 III. Response with PCTs (Programmable Communicating Thermostats)

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 20 /29 Data Analysis for PCT Group Divide hourly data (24-hour load shapes)  5°F peak temperature bins  Normal/critical days Average load shapes across days for each customer Average load shapes across customers  PCT sample not stratified

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 21 /29 PCT Response, by 5°F Temperature Bin

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 22 /29 5-hour PCT Response, 90-95°F Average Response = -25%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 23 /29 2-hour PCT Response, 90-95°F Average Response = -41%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 24 /29 2-hour PCT Response, 80-85°F Average Response = -16%

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 25 /29 Average Normal Load Shapes: Manual and PCT Groups, 70-95°F

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 26 /29 Manual vs. PCT Response, by 5°F Temperature Bin

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 27 /29 California System Response Potential under Mandatory CPP: Recent ISO Emergencies A. Date B. Peak Load C. Temperature Exposure D. All Manual Response E. Manual and PCT Response Res. (GW) System (GW) >90°F (%) >95°F (%) Res. (%) Res. (GW) System (%) Res. (%) Res. (GW) System (%) 7/10/ /22/ /21/ /9/ /28/ /29/

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 28 /29 Conclusions In hot weather, households on CPP tariffs alone (without technology) reduced peak load by 13% over a 5-hour critical event period In hot weather, households on CPP tariffs coupled with programmable communicating thermostats reduced peak load by 25% over a 5-hour critical event period and 41% over a 2-hour critical peak period Comparable groups with and without PCTs responded similarly in mild weather, but PCT customers outperformed manual customers in hot weather Assuming similar response by all California customers, residential CPP tariffs could have reduced system load by 1- 4% during recent California ISO events

February 23, 2006Karen Herter, LBL/CEC/UCB-ERG 29 /29 The End Full report available at: (or just search the LBL library for LBNL-58956)