Conservation Voltage Reduction (CVR) Phillip Anderson P.E. Engineering Project Leader Research, Development & Deployment

Conservation Voltage Reduction (CVR) Phillip Anderson P.E. Engineering Project Leader Research, Development & Deployment

Presentation Outline Background Information on CVR CVR Definition Voltage Control Theory CVR Theory Northwest Energy Efficiency Alliance Distribution Efficiency Initiative (DEI) Pilot Study Idaho Power CVR Implementation to Date

What is Conservation Voltage Reduction? By reducing distribution feeder service voltage, Conservation Voltage Reduction (CVR) promises to reduce energy consumption.

What is Service Voltage? Voltage at point of delivery (at the meter) National Service Voltage Standard (ANSI C84.1) Range A or Normal Conditions: 114 V-126 V Allows ± 5% service voltage bandwidth All electric devices operate properly Typical Urban Feeder operates in upper half (120-126 V) 126 Volts National Standard Typical Urban Feeder +5% 120 Volts 0% 114 Volts -5%

Typical Urban Feeder Voltage Profile 126 124 Volts at Substation Typical Service Voltage Service Volts 124 122 120 118 120 Volts Minimum on Feeder Pre CVR 116 114 0 0.5 1 1.5 2 2.5 3 3.5 4 Miles from Substation

Voltage Drop Along a Feeder example http://wiki.powerdistributionresearch.com/index.php?title=file:voltage_profile_distribution.jpg

Feeder Reality

How do we control Voltage on a Feeder? Substation Transformer Load Tap Changer (LTC) or Station Voltage Regulator settings LTC or Regulator Controller Voltage Band Center or Base Voltage Voltage Bandwidth (deadband) Line Drop Compensation (LDC) End of Line (EOL) Voltage Control Not used by Idaho Power, requires EOL voltmeters, communications and a control system

Why CVR? Lower voltage by 2-4% Lower Voltage by 2-4% 1-3% Reduction in: Energy (kwh) Peak Demand (kw)

Service Voltage National Service Voltage Standard (ANSI C84.1) Range A or Normal Conditions: 114 V-126 V Allows ± 5% service voltage bandwidth All electric devices operate properly Typical Urban Feeder operates in upper half (120-126 V) 126 Volts National Standard Typical Urban Feeder Urban Feeder with CVR +5% CVR Goal: Operate in lower half (114-120 V) 120 Volts 0% 114 Volts -5%

Typical Urban Feeder Voltage Profile with CVR 126 124 Volts at Substation Typical Service Voltage Service Volts 124 122 120 118 116 114 120 Volts at Substation 0 0.5 1 1.5 2 2.5 3 3.5 4 Miles from Substation 120 Volts Minimum on Feeder Pre CVR CVR 116 Volts Minimum on Feeder

What are the challenges of implementing CVR? Voltage drop along a feeder may limit potential CVR feeder candidates Substation and feeder design/configuration may limit potential CVR candidates Ensure the first customer as well as the last customer are within voltage limits (114-126 volts) Complicated feeder layouts make determination of the EOL challenging Lots of modeling and load flow analysis and monitoring are necessary

2007 Pilot Study Northwest Energy Efficiency Alliance Distribution Efficiency Initiative (DEI) Lowered Voltage at one substation (Boise Sub) ~ 3% End of line feedback 24 hrs on, 24 hrs off Results: 1.5% - 2.5% Energy reduction (kwh) 1.8% - 2.6% Demand reduction (kw) NORTHWEST ENERGY EFFICIENCY ALLIANCE DISTRIBUTION EFFICIENCY INITIATIVE PROJECT FINAL REPORT

CVR Data DEI Pilot Study NORTHWEST ENERGY EFFICIENCY ALLIANCE DISTRIBUTION EFFICIENCY INITIATIVE PROJECT FINAL REPORT

BOIS T134 Demand (kw) Reduction NORTHWEST ENERGY EFFICIENCY ALLIANCE DISTRIBUTION EFFICIENCY INITIATIVE PROJECT FINAL REPORT

CVR Energy Reduction Where does the 1.5 to 2.5 % CVR energy reduction come from (for voltage reduction only)? End User: 80% - 90% Power System Efficiency Gains: 10% - 20% Direct benefit for customers: For typical 1000 kwh/month residential customer: Reduce 90-180 kwh/year

2009 CVR at Idaho Power Reviewed over 600 feeder circuits for CVR potential 264 feeder circuits in 81 substations were potential candidates 30 feeder circuits selected based on extensive load flow analysis Implemented CVR at 6 Substations (30 feeder circuits) 4 in Boise area 1 in Nampa area 1 in Pocatello 29,600 customers 160 MW peak demand Modified settings in substation transformer equipment Expenses: Engineering studies Technician time to change substation settings

Load Tap Changer (LTC) Line Drop Compensation settings changes Typical Substation Transformer LTC Settings Base V = 122 volts Bandwidth = 3 volts R = 2 volts New CVR Substation Transformer LTC Settings (9 transformers at 6 substations) Base V = 118.8 to 119.7 volts Bandwidth = 3 volts R = 3 to 6 volts

2010/11 CVR at Idaho Power Re-examined 69 feeder circuits of the 264 candidates using new load data 9 feeder circuits showed promise based on extensive load flow analysis for being potential CVR candidates Reviewed feeder circuits for potential candidates with minimal circuit upgrades 4 potential CVR candidates identified Not yet implemented

Review Distribution feeder voltage CVR DEI study Idaho Power CVR to date

Questions?