Shared Guidelines

Last updated: January 29th, 2026

1 Overview

1.1 Introduction.

1.1.1 This document describes the methods used by WattCarbon for estimating hourly impacts from electricity consumption or production, where a power grid connects multiple end users and where production resources are shared amongst all interconnected Assets. These methods yield hourly Asset-level Energy Attribute Certificates.

1.1.2 This methodological specification is intended to provide transparency and auditability. There are a significant number of choices that are made when conducting measurement and verification of Assets, the results of which can significantly change the results. By illuminating these choices, this document provides an opportunity to create standards for certain choices, and to allow flexibility for others, so long as each choice is documented.

1.1.3 As a rule, these methods are written for a technical audience of practitioners, however, where useful, a pragmatic effort is made to provide interpretation and context for use cases.

1.1.4 This is a “living” document, in the sense that we continue to work to change or update existing guidance as additional evidence arises supporting new approaches or challenging current approaches. These methods are version controlled to allow users to pin their programs, policies, or analysis to a particular instantiation of the methods. The latest version will always reflect what we believe to be the most complete and well-tested approach.

1.1.5 To further assist with referenceability and versioning, this document provides a numbering scheme to facilitate referencing the methods. As the numbering scheme may change as the methods are tested and refined, it should be used in combination with a document version to prevent ambiguity.

1.1.6 These methods are designed to be general enough to implement using any general-purpose programming language and are not required to be deployed with any particular software implementation.

1.2 Participation in methods development.

1.2.1 WattCarbon has organized the OpenEAC Alliance to encourage industry participation in the development of decarbonization accounting methodologies. Learn more at www.openeac.org.

1.3 Scope.

1.3.1 Some items have been considered to be generally in-scope for improvements to these methods.

1.3.1.1 Technical clarifications or improvements to existing methods.

1.3.1.2 Methods for calculating uncertainty or establishing criteria for use cases.

1.3.1.3 Empirical tests to evaluate methodological choices and assumptions.

1.3.2 Some items have, to date, been considered out-of-scope:

1.3.2.1 Analysis or evidence based in datasets which cannot be otherwise replicated

1.3.2.2 Non-energy emissions accounting

1.3.2.3 Programming language or implementation-specific constraints.

1.3.2.4 Proprietary, closed-source, or restrictively-licensed algorithms, procedures, or content.

1.4 What is an EAC?

1.4.1 An EAC captures the externality value of energy or carbon savings. When a project or Asset is deployed and results in energy or carbon savings, the benefit is shared collectively. The EAC is a way to assign responsibility for the collective good to an individual party. One EAC is generated per Asset per hour.

1.4.2 Some attributes include:

1.4.2.1 Energy Impact

1.4.2.2 Capacity Impact

1.4.2.3 Carbon Impact

1.4.2.4 Cost Impact

2 Data Management

2.1 Data Inputs.

2.1.1 Asset Location Information.

2.1.1.1 Address. Primary street address where the Asset is located

2.1.1.2 Address 2. Secondary address line for the Asset location

2.1.1.3 City. City where the Asset is located

2.1.1.4 State. State where the Asset is located

2.1.1.5 Zip Code. ZIP code where the Asset is located

2.1.1.6 Latitude. Geographic latitude coordinate of the Asset location

2.1.1.7 Longitude. Geographic longitude coordinate of the Asset location

2.1.2 Additional required inputs are specified in each individual methodology document

2.2 Guidelines for handling data quality issues

2.2.1 In many cases, data quality issues can be resolved by going back to the source to resolve issues in export or transfer. This guidance is a second line of defense for handling or correcting for common data issues, and is provided in the hope of mitigating the myriad issues and discrepancies which arise using different methods for data cleaning.

2.2.2 Individual methodologies and implementations will have more specific audits, but in general the following are considered good practice:

2.2.2.1 Extreme values: Usage values that are more than three interquartile ranges larger than the median usage should be flagged as outliers and manually reviewed.

2.2.2.2 Generally recommend an audit for dataset completeness using expected counts of Assets, meters, and carbon emissions totals.

2.2.2.3 Roll up data if not given with expected frequency.

3 Information content of the digital certificate

3.1 The digital certificates resulting from a verification methodology shall contain the following information:

3.1.1 Asset information:

3.1.1.1 Name of the Asset

3.1.1.2 A unique identifier for the certificate

3.1.1.3 Date when the Asset began making an impact

3.1.2 Location information for the Asset

3.1.2.1 Longitude

3.1.2.2 Latitude

3.1.2.3 Address

3.1.3 Time information about the period:

3.1.3.1 Start timestamp

3.1.3.2 End timestamp

3.1.4 . Energy content:

3.1.4.1 Net energy impact for the time period

3.1.5 Emissions content:

3.1.5.1 Average emission intensity of the grid over the period

3.1.5.2 Source of the average emission intensity data

3.1.5.3 Identifier of the grid region corresponding to the emission intensity data

3.1.5.4 If emitted or avoided emissions are based on the carbon intensity of a fixed fuel source, the intensity as well as related provenance must be included

3.1.6 Details about certificate issuance:

3.1.6.1 Timestamp when the certificate was generated

3.1.6.2 Country for which the certificate is issued

3.1.6.3 A link to the verification methodology (where the URL points to the specific version used to generate the certificate)

3.1.7 Legal information:

3.1.7.1 Name of certificate owner

3.1.7.2 Name of the Asset owner

4 M&V Plan

4.1 The M&V Plan shall be a document that outlines the agreement between the registry and supplier of the project that states how methodologies were implemented and outlines the role and responsibility of each party. Key considerations shall be outlined in the M&V Plan. They should at minimum include:

4.1.1 The breadth of projects that the M&V Plan will cover.

4.1.2 Selection of the source for carbon intensity data.

4.1.3 The time period a project will be available to certify EACs.

4.1.4 How the data will be exchanged between the supplier and registry and the agreement for the timeliness of this exchange.

4.1.5 Who is responsible for the Measurement & Verification.

4.1.6 Who is responsible for the reproduction of data, savings results, and methodological adherence to this method.

4.1.7 Definition of Ownership for the claims to the credit.

4.1.8 Monitoring of Trigger Events / non-routine adjustments: Examples include significant operational changes or new regulatory requirements that may require an adjustment to the analysis.