1. What's an EAC?

    An EAC is an Energy Attribute Certificate, which represents a unique claim to the environmental benefits of energy decarbonization projects. EACs are watt-hour tracking instruments that specify all attributes of clean energy, including resource type, production time and location, local grid carbon emissions intensity, resource operation start date, and related market and contract information.

    For more information on EACs see:

  2. What’s the difference between an EAC and a REC?

    An Energy Attribute Certificate (EAC) is a more inclusive certificate that includes other attributes beyond a volumetric amount of generated renewable energy. EACs can specify multiple attributes including the specific time of day in which the energy value was generated, the type of resource, the precise location of the resource, and the carbon intensity of the grid at the time of day in which the energy value was generated.

    As such, EACs enable transparency and procurement based on the exact impacts of each watt-hour of clean energy.

  3. What are the units of measurement in an EAC?

    All EACs are tracked in units of watt-hours, following established industry methodologies. Every watt-hour is time stamped and tied to a particular asset location. EACs also quantify carbon reductions to the gram. The average consumed emissions intensity, as measured by the United States Energy Information Agency for the local balancing authority for the hour of the day, is used to calculate the carbon load of each watt-hour of electricity.


  1. What can I buy from WattCarbon’s open EAC market?

    WattCarbon’s open market sells listings of aggregated EACs for energy decarbonization projects across the U.S. Projects include renewable energy generation as well as distributed energy resources, like demand response, energy efficiency, battery storage and electrification.

    EACs are generated by the watt-hour, and are aggregated by specific attributes, such as by balancing authority, time of day, or date range. EACs include all energy attributes so you can know the exact impact of your purchase.

    WattCarbon EACs all include the Operation start date for their registered unit, so buyers may assess if EACs meet specific incrementality requirements.

  2. What is an EAC subscription?

    EAC subscriptions offer multi-year fixed-price procurement based on desired attributes. Subscriptions are pay-as-you-go and offer a flexible solution for long term procurement. EACs delivered through subscriptions are all additional from new projects, which were enabled due to EAC subscription funding.

    Contact us to learn more about enrolling in an EAC subscription.

  3. What is a vPPA for distributed energy resources?

    vPPAs for DERs enable any organization to scale the deployment of new clean energy projects that meet their unique climate goals. Organizations commit to buying the total aggregated EACs for the resource lifespans. The EAC capital is used to lower consumer costs, reducing barriers and accelerating deployment. New projects are developed & clean energy goes online within months.

    When contracting a vPPA for DERs, an organization may focus on specific attributes that are important to their goals, including targeting any US market, optimizing for grid carbon intensity, or expanding access to the social & equity benefits of distributed clean energy.

  4. How does WattCarbon aggregate distributed energy projects?

    WattCarbon unifies distributed energy resource suppliers across the United States with organizations looking to procure EACs to meet their clean energy goals. When contracting vPPAs, WattCarbon works with organizations to understand their procurement volume and attribute preferences, and facilitates fulfillment of that procurement by working with one or several DER supplier partners to aggregate new clean energy projects. All projects are registered in The WattCarbon Energy Attribute Tracking System (WEATS), and EACs for every watt-hour of clean energy are delivered to the procuring organization.

Carbon Accounting

  1. How do I retire my EACs?

    Once your EACs have been delivered to your account, you will have the option of holding on to them, retiring them, or making them available for resale. WattCarbon provides full functionality for hourly EAC and REC management.

  2. If I want to retire some of my EACs but not all of them, can I do that?

    Yes. EACs in your account are grouped in hourly increments. You may retire any hourly combination of EACs.

  3. How do you calculate the carbon emissions associated with renewable energy and demand response?

    WattCarbon uses publicly available data provided by the United States Energy Information Agency sourced from daily reports provided by the 65 balancing authorities that manage grids across the United States. The EIA calculates a consumed carbon intensity for each grid for each hour of the day using open source methods for estimating the carbon intensity of imported and exported energy alongside energy produced and consumed within a grid. The consumed carbon emissions divides total emissions by total electric consumption for each hour of the day and is reported in grams/kWh.

  4. How does WattCarbon ensure that EACs are not counted twice?

    WattCarbon’s registry prevents double counting by assigning a unique ID for every watt-hour for each EAC, and co-registering & retiring the certificates across other registries. The unique identifier enables WattCarbon to identify the specific source and timing of the Environmental Attribute Right and allows for complete auditability for all transactions. The registry is designed to maintain compliance with the requirements of existing standards, such as the GHG Protocol.