Building a foundation
of trust with open source

We believe that open source methodologies, software and collaboration are key to developing the foundational weights and measures required to bring demand flexibility to market.
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Why we believe in open source

Transparent measurement

Transparent measurement builds the trust markets need to facilitate transactions that all parties can agree on.

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Replicable methods

Standard inputs combined with replicable methods provide reproducible results, giving public and private entities confidence that their calculations will be consistent with other third parties.

Explore the methods

Available without restriction

Anyone can download, modify and use open source software. This prevents vendor lock in and enables a transparent and collaborative development process.

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Open stakeholder development

Nearly 100 experts representing utilities, regulators, implementers, evaluators and academic researchers have helped develop the open source methods and code.

Join The Process

Markets Need Transparent Standard Weights and Measures

The OpenEEmeter implements the CalTRACK methods to support transparent market transactions. Both the OpenEEmeter and CalTRACK are supported by the Linux Foundation, one of the largest open source foundations in the world.

CalTRACK specifies a set of empirically tested methods to standardize the way normalized meter-based changes in energy consumption are measured and reported.

  • Standard Measurement and Verification methods.

  • Developed in a public and collaborative empirical process.

  • Detailed documentation of Monthly, Daily, and Hourly approaches.

The OpenEEmeter software calculates changes in energy consumption for building efficiency projects and portfolios by  implementing the CalTRACK methods in a consistent and replicable way.

  • Python Engine to consistently execute CalTRACK methods.

  • Open Source License Apache 2.0.

  • Available without restriction.

  • Innovation through continued collaboration.

Posted on May 15, 2019

Recurve Joins Linux Foundation Energy and Contributes the OpenEEmeter

Read the press release

We are proud to be founding members of LF Energy and to have contributed both the OpenEEmeter and the Energy Market Methods Consortium (EM2) to the organization.

Following CPUC ruling (D.12-05-015) in 2012, energy efficiency industry leader Matt Golden began assembling a team to develop open source methods and software to enable standard measurement of energy savings.

In 2015, Matt founded Recurve (then OpenEE). Recurve has dedicated itself to the development of the open source CalTRACK methods and OpenEEmeter software. See the full history at

The History of OpenEEmeter & CalTRACK

World wide adoption of CalTRACK and the OpenEEmeter

Across the world State agencies, Utilities and Implementers are using CALTRACK and the OpenEEmeter in over 20 commercial implementations.

How the OpenEEmeter works

The OpenEEmeter calculates, in a consistent and replicable way, how an intervention changes a building's metered energy consumption.

CalTRACK 2.0

Hourly Methods

The CalTRACK Hourly method models building energy use as the interaction between the building’s temperature dependence, the occupancy status and the time of week.


Learn how to enable transparency in your savings results

It's time to end black box M&V. Contact us to learn how to enable transparent results for your program.

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