Distribution Measures: Voltage Reduction and Optimization Josh Rushton CVR/VO Subcommittee May 8, 2015

Today’s objective RTF request (from January): Estimate lift needed to resolve major concerns with existing protocols:January Balance flexibility, reliability, ease-of-use – Performance thresholds – General approach Miscellaneous – Clarify terms (e.g., “mostly residential”) – Measure life issues – Narrow technical questions Lift-size estimate should reflect particular goal(s) Today’s objective: Recommendation on how major concerns should be addressed in CVR/VO protocols 2 Especially this

Outline Overview – Background – The big issues – Reminder on scope and objectives (Simplified) Voltage Optimization Protocol – How it works – Performance thresholds – Discussion (Automated) CVR Standard Protocol #1 – How it works – Performance thresholds – Discussion 3

Overview 4 – Overview

Where do CVR savings come from? Basic idea: Some things use less energy at lower voltages Complication 1: Average ΔV can be hard to estimate Complication 2: 5 – Overview Savings factor (%ΔKWh per %ΔV) depends on mix of end uses. See (PNNL, 2010) for some lab results ΔVΔV Artist’s rendering (fake data)

Two standard protocols… (Simplified) VO Protocol (Latest draft (under review) November, 2012)Latest draft (under review) November, 2012 “Canned” savings factors (%ΔKWh/%ΔV) derived from NEEA’s DEI research Factors vary by climate, AC saturation, and ER heat saturation Factors based on data collected at residential end-user meters – Capture savings on customer side of meter (separate calculations needed for distribution savings) – Apply to mostly-residential feeders (Automated) CVR Protocol #1 (Latest draft (under review) May 15, 2012)Latest draft (under review) May 15, 2012 Uses alternating CVR-on/CVR-off data to estimate savings factor (%ΔKWh/%ΔV) Directly measures switchable savings (models bring in other components) Factors based on feeder-level data (captures savings on both sides of meter) 6 – Overview

Big issue 1: Performance thresholds Performance thresholds enable deeper savings (greater ΔV) in many cases – Good reason for recommendation but not for requirement – Shouldn’t include in our test Question for today: When are performance thresholds needed… – For reliable savings estimates? – For defining obsolete equipment? 7 – Overview

Big issue 2: General approach BPA suggests some form of “custom guidance” Advantage over using existing protocols: flexibility Advantages over deactivating existing protocols: – Could preserve simplified option, give VO tables a home – RTF can draw some boundaries for M&V Disadvantages (other than having to come up with “custom guidance”): – Savings calculations could be complicated, diverse Would need careful documentation and expert review BPA custom project process includes review by ESUE engineer What kind of RTF document would this be? – RTF does not approve “methods” for custom protocols (Roadmap, p.7) – An uncommonly flexible Standard Protocol might fit with Guidelines Wouldn’t attempt to spell out all calculations Would probably rely on practitioner credentials (how to specify?) – Don’t have a detailed proposal for this. Question for today: Can something like this achieve reliable savings estimates? 8 – Overview

Reminder: Scope and Objectives Protocol savings estimates should be “right on average” RTF exists to support use of EE as a resource. Protocols reflect trade-offs between reliability and research expense that are appropriate for that role. May have insufficient rigor for other purposes (such as capital improvement decisions) Bundling, when a group of related measures is cost- effective even though some individual components are not RTF tries to avoid policies that require or ban bundling. 9 – Overview

(Simplified) Voltage Optimization Protocol 10 – Simplified VO Protocol

Two standard protocols… (Simplified) VO Protocol (Latest draft (under review) November, 2012)Latest draft (under review) November, 2012 “Canned” savings factors (%ΔKWh/%ΔV) derived from NEEA’s DEI research Factors vary by climate, AC saturation, and ER heat saturation Factors based on data collected at residential end-user meters – Capture savings on customer side of meter (models needed for distribution savings) – Apply to mostly-residential feeders (Automated) CVR Protocol #1 (Latest draft (under review) May 15, 2012) Uses alternating CVR-on/CVR-off data to estimate savings factor (%ΔKWh/%ΔV) Directly measures switchable savings (models bring in other components) Factors based on feeder-level data (captures savings on both sides of meter) 11 – Simplified VO Protocol

Primary electrical systems serving mostly residential and light commercial loads For each affected feeder, must be able to record hourly averages for a week pre- and a week post: – voltage (source and EOL, by phase), – ambient temperature (source), – KW and Kvar (source) Minimum performance thresholds – Based on 7-days of hour-level data for reflecting normal operation pre and post-VO… 12 – Simplified VO Protocol Eligibility

Step 1. (Identify Savings Factor) Look up VOf (%ΔkWh / %ΔV) in table Table based on NEEA Load Research Project Values vary by climate, saturation of AC and ER heat VOf only counts end-user energy savings (distribution losses calculated separately ) Step 2. (Estimate Energy Savings) ΔkWh (savings) = kWh ANNUAL * VOf * %ΔV kWh ANNUAL based on historical data ΔV is estimated average voltage difference between CVR- on and CVR-off cases 13 – Simplified VO Protocol Steps to estimating savings Big question #1: Are the performance thresholds needed for ∆V?

14 – Simplified VO Protocol Simple ΔV Formula

Power factor (3-phase total, at source): – Minimum (hourly) greater than 0.96 – Average (for week) greater than 0.98 Phase load balance (3-phase lines, at source) – Per-unit unbalance < 0.15 – Neutral < 40 amps Max-adjusted voltage drop (3-phase mean) – Max-adjusted drop is mean meter-period drop, times (annual peak kW) / (mean meter-period kW) – Primary max-adjusted drop < 3.3% – Secondary max-adjusted drop < 4.0% 15 – Simplified VO Protocol Performance Thresholds (1)

Variation between feeder max voltage drops – Compare feeders within substation control zone – Must not differ by more than 2 Volts (on 120 V base) Primary line minimum hourly voltage – Measured near expected low voltage point – At least 114 V + (1/2) Voltage regulation bandwidth + secondary max allowed voltage drop Primary line maximum hourly voltage – Measured near expected high voltage point – Less than 126 V - (1/2) Voltage regulation bandwidth Conductor loading – Source hourly loading (amps) less than design normal spec 16 – Simplified VO Protocol Performance Thresholds (2)

Are the thresholds needed to get “reliable” average ΔV from the Simple Formula? Is a system obsolete (inevitable near-term improvements) if thresholds aren’t met? Conclusions/recommendations related to general approach? 17 – Simplified VO Protocol Discussion

(Automated) CVR Standard Protocol #1 18 – CVR Protocol #1

Two standard protocols… (Simplified) VO Protocol (Latest draft (under review) November, 2012) “Canned” savings factors (%ΔKWh/%ΔV) derived from NEEA’s DEI research Factors vary by climate, AC saturation, and ER heat saturation Factors based on data collected at residential end-user meters – Capture savings on customer side of meter (models needed for distribution savings) – Apply to mostly-residential feeders (Automated) CVR Protocol #1 (Latest draft (under review) May 15, 2012)Latest draft (under review) May 15, 2012 Uses alternating CVR-on/CVR-off data to estimate savings factor (%ΔKWh/%ΔV) Directly measures switchable savings (models bring in other components) Factors based on feeder-level data (captures savings on both sides of meter) 19 – CVR Protocol #1

System type. Primary electric distribution systems serving any combination of res., comm., and industrial loads, operated radially, primary voltage ≥ kV CVR control. CVR system can be switched on and off on a daily basis (voltage set points can be changed daily) System model. Protocol relies on load flow simulation model. Data collection. For each affected feeder, must be able to record hourly average… – voltage (source and EOL, by phase), – ambient temperature (source), – KW and Kvar (source) Performance thresholds… 20 – CVR Protocol #1 Eligibility

Step 1. (Data collection) Metering at feeder source: – Hourly average kW, kvar, voltage (each phase), temperature Metering at “EOL” locations: – Select low-voltage points based on load flow simulation – Collect voltage (hour-level averages for each phase and low-voltage point) Select 90 days for on/off CVR operation with data collection – Spread over the year, 30-day groups (get range of conditions) 21 – CVR Protocol #1 Steps to estimating savings

Step 2. (Regression) Estimate CVRf (%ΔkWh / %ΔV) via regression model fit with hour-level data. Dependent variable is: kWh Explanatory variables are: CDD, HDD, “zone-average” V CVRf estimate is the coefficient of voltage variable. Step 3. (Estimate Energy Savings) ΔkWh (savings) = kWh ANNUAL * CVRf * %ΔV kWh ANNUAL based on historical data ΔV is difference between estimated control-zone-average voltage levels in CVR-on and CVR-off cases 22 – CVR Protocol #1 Steps to estimating savings Does this ∆V need to be right, or just consistent with regression?

Prior to CVR installation, do separately for each voltage control zone: 1.Collect historical data – Load shape, total energy, kvar data, customer mix, ER heat and AC kWh estimates 2.Run load flow simulation model for Pre- and Post-CVR cases – Base on physical configuration, historical data, and proposed upgrades. 3.Use simulation model to test whether Pre- and Post-CVR systems meet performance thresholds: – Max. phase load imbalance < 20% (check peak/min kW) – Min. hourly power factor > 95% (check peak/min kW, peak/min kVA) – Voltage complies with ANSI C84.1 (check at EOL for peak/min kW ) 23 – CVR Protocol #1 Performance assessment

Are the thresholds needed to get “reliable” average ΔV from the Simple Formula? Is a system obsolete (inevitable near-term improvements) if thresholds aren’t met? Conclusions/recommendations related to general approach? What about other statistical approaches? 24 – Simplified VO Protocol Discussion

Additional Slides 25 – Additional slides

Measure is operational, so persistence is tricky Protocol specifies “post-period re-verification trigger” Annual persistence review for three years after installation. Check for changes in standard operation – Source voltage (min, max, average), – Weather-adjusted annual energy – Average primary voltage – kW, kvar demand Any change ≥ 15% triggers full protocol do-over Is this how we want to treat persistence? Relevant to Simplified VO too, but not as much work to redo there 26 – Additional slides Additional Slide: CVR #1 Persistence

References NEEA DEI Project Final Report (NEEA, 2008) – Load Research Project ( ) – Pilot Demonstration Project (c ) Distribution Efficiency Guidebook (NEEA, 2008) Long-Term Monitoring and Tracking DE (NEEA, 2014) Energy Smart Utility Efficiency (ESUE) Program (BPA, ongoing) PacifiCorp’s DE Pilot Study Avista CVR Program Impact Evaluation (Avista, 2014) Evaluation of CVR on a National Level (PNNL, 2010) M&V research by PNNL and WSU researchers (2014) Green Circuits DE Case Studies (EPRI, 2011) 27 – Additional slides