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

2

Today’s objective

• • RTF request (from January ): Estimate lift needed to resolve major concerns with existing protocols: Balance flexibility, reliability, ease-of-use – Performance thresholds – General approach Miscellaneous – Clarify terms (e.g., “mostly residential”) – Measure life issues – Narrow technical questions

Especially this

Lift-size estimate should reflect particular goal(s)

Today’s objective: Recommendation on how major concerns should be addressed in CVR/VO protocols

3

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

4 – Overview

Overview

5 – Overview

Where do CVR savings come from?

Basic idea: 126 124 Some things use less energy at lower voltages 122 120 ΔV 118 Complication 1: 116 114 Average ΔV can be hard to estimate Complication 2: 112 0 2 4 Miles from substation 6 Savings factor (%ΔKWh per %ΔV) depends

Artist’s rendering (fake data)

8 on mix of end uses. See (PNNL, 2010) for some lab results

6 – Overview

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 (separate calculations 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)

7 – 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?

8 – 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?

9 – 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.

10 – Simplified VO Protocol

(Simplified) Voltage Optimization Protocol

11 – Simplified VO Protocol

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) • • 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)

12 – Simplified VO Protocol

Eligibility

• • • 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…

13 – Simplified VO Protocol

Steps to estimating savings

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 kWh ANNUAL * VOf * %ΔV based on historical data

Big question #1: Are the performance thresholds needed for ∆V?

ΔV is estimated average voltage difference between CVR on and CVR-off cases

14 – Simplified VO Protocol

Simple ΔV Formula

For fixed voltage reduction, VO Protocol estimates average voltage as follows, pre and post, and takes the difference: 𝑉 = 𝑉 𝑆𝑒𝑡 − 1 2 ∗ 𝐴𝑣𝑒 𝑉 𝑂𝑢𝑡,𝑖 − 𝑉 𝐸𝑂𝐿,𝑖 ∗ 𝐷 𝑎𝑛𝑛𝑢𝑎𝑙 𝐷 𝑚𝑒𝑡𝑒𝑟 𝑉 𝑆𝑒𝑡 𝑉 𝑂𝑢𝑡, 𝑖 𝑉 𝐸𝑂𝐿, 𝑖 = Regulator set point voltage setting = Hour-i metered regulator output voltage on 120 V base = Hour-i metered EOL primary voltage on 120 V base 𝐷 𝑎𝑛𝑛𝑢𝑎𝑙 = Average annual kW demand (from measured historical data) 𝐷 𝑚𝑒𝑡𝑒𝑟 = Average kW demand, metered at source (Formula for line drop compensation and automated voltage feedback control adds correction for volt rise.)

15 – Simplified VO Protocol • • •

Performance Thresholds (1)

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%

16 – Simplified VO Protocol • • • •

Performance Thresholds (2)

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

17 – Simplified VO Protocol

Discussion

• 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?

18 – CVR Protocol #1

(Automated) CVR Standard Protocol #1

19 – 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 ) • • 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)

20 – CVR Protocol #1 • • • • •

Eligibility

System type. Primary electric distribution systems serving any combination of res., comm., and industrial loads, operated radially, primary voltage ≥ 12.47 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…

21 – CVR Protocol #1

Steps to estimating savings

• • •

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)

22 – 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 kWh ANNUAL * CVRf * %ΔV based on historical data

Does this ∆V need to be right, or just consistent with regression?

ΔV is difference between estimated control-zone-average voltage levels in CVR-on and CVR-off cases

23 – CVR Protocol #1

Performance assessment

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 )

24 – Simplified VO Protocol

Discussion

• 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?

25 – Additional slides

Additional Slides

26 – Additional slides

Additional Slide: CVR #1 Persistence

• • • • • • • 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

27 – Additional slides

References

• • • • • • • • • NEEA DEI Project Final Report (NEEA, 2008) – Load Research Project (2005-2007) – Pilot Demonstration Project (c. 2005-2007) 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)