Voltage Optimization

At a Glance

Status

active

Fuel type

electric

Sector

utility system efficiency

Applications

utility distribution system

Sunset date

Jul 31, 2027

This protocol supports estimating end-user and utility kWh savings caused by lowering distribution voltage, which can reduce consumption for some devices. The protocol provides a simplified method for estimating savings based on tabulated VO factors, and it provides research and evaluation guidance. An eligible project is any reduction in distribution voltage that satisfies these requirements: (a) the project applies to a predominantly residential voltage control zone for the purpose of conserving energy, and (b) the practitioner is able to reliably estimate average annual change in voltage experience by end users. The protocol includes Benchmark Performance Thresholds and a Benchmark Method for estimating annual weighted-average change in voltage. When the Benchmark Performance Thresholds are met, the Benchmark Method provides adequate reliability for RTF-approve kWh savings. For all other cases, the protocol requires that certain validity threats are addressed so that the estimated change in annual weighted-average voltage has reliability similar to what is typically achieved by the Benchmark Method when the Benchmark Thresholds are met.

Standard Protocols

Latest Version

Voltage Optimization Standard Protocol v3.0.1

Voltage Optimization Standard Protocol v3.0.1

Approved at July 2025 RTF meeting. Undergoing QA

Date

Jul 30, 2025

Version number

3.0.1

Past Versions

version	date	document
2.1	Jul 21, 2020	Voltage Optimization Standard Protocol v2.1 Approved at the July 2020 RTF meeting.
2.0	Nov 23, 2015	VoltageOptimzationProtocol_v2_0.pdf
1.0	May 04, 2010	VoltageOptimization_Protocol_v1.pdf

Calculator

Latest Version

Voltage Optimization Savings Calculator v3.0.1

Approved at July 2025 RTF meeting. Undergoing QA

Date

Jul 30, 2025

Version number

3.0.1

Past Versions

version	date	document
2.1	Jul 31, 2021	Voltage Optimization Savings Calculator v2.1 Corresponds to version 2.1 of the protocol. Updated with minor changes for clarity.
1.2	Oct 04, 2016	Voltage Optimization Savings Calculator v1.2 Calculator corresponds with v2.1 of the protocol.

Decisions

Expand All Decisions

Latest decision

Decision details

Decided

July 22, 2025

Approve Standard Protocol Updates

Decision Details

Approve updates ot the Voltage Optimization Standard Protocol as presented, and:
Keep the Status at Active
Modify the customer-side CVR-f by a factor of 0.86
Add default savings values for utility-side savings, 10% of customer side savings
Set the sunset date to July 31, 2027

Decided

July 21, 2020

Approved Measure Updates

Decision Details

Updated the Voltage Optimization Standard Protocol as presented:

Keep the Status at Active
Set the Sunset Date to July 2025

Decided

July 21, 2015

Approve measure update

Decision Details

Approve the Standard Protocol for Voltage Optimization as presented: Set the status to 'Active'; Set the category to 'Proven'; Set the sunset date to July 31, 2020.

Decided

May 04, 2010

Approve Standard Protocol

Decision Details

RTF adopted the simplified voltage optimization protocol as proposed.

Voltage Optimization

About the RTF

Work Products

Subcommittees

Voltage Optimization Standard Protocol v3.0.1

Voltage Optimization Savings Calculator v3.0.1

Approve Standard Protocol Updates

Approved Measure Updates

Approve measure update

Approve Standard Protocol