NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Renewable Energy 

Certificate (REC) Tracking 

Systems: Costs & 

Verification Issues

Jenny Heeter, Renewable Energy 

Analyst

National Renewable Energy 

Laboratory

October 11, 2013

NREL/PR-6A20-60640
2

Purpose of this Document

This document provides information on REC tracking 

systems: how they are used in the voluntary REC 

market, a comparison of REC systems’ fees and 

information regarding how they treat environmental 

attributes. 
3

What are REC Tracking Systems?

• Renewable energy certificate “REC” tracking systems are electronic 

tracking systems that ensure that RECs are only “retired” once. 

“Retirement” of a REC means that the REC has been used by the owner; it 

can no longer be sold. 

• Tracking systems work by assigning a unique serial number to each 

megawatt-hour of renewable energy generation, which constitutes a REC. 

• Tracking systems were originally created to facilitate renewable portfolio 

standard (RPS) compliance, but increasingly, voluntary RECs are also 

utilizing REC tracking systems.

• Renewable generator participation in REC tracking systems is fairly high 

due to state RPS requirements that generators participate in REC tracking 

systems. So, if a generator wants to sell RECs to meet RPS compliance, it 

will in most states will be required to use a REC tracking system. 
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Tracking Systems are Regionally Based; 

Cover the Entire U.S.

Source: Updated from ETNNA 2011

Note: NAR covers states not covered by a APX, Inc. tracking system

Note: Nevada uses both NVTREC and WREGIS
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Tracking Systems Simplify Green-e Audit

• The Center for Resource Solutions (CRS) 

administers Green-e programs. 

• Participants in the Green-e program are 

audited annually to substantiate product 

purchases, sales, and claims. The audit is 

performed by an independent certified public 

accountant or certified internal auditor in 

accordance with a protocol established by 

Green-e. 

• The auditor may utilize retirement reports 

available through REC tracking systems, 

which simplifies the audit process since it 

streamlines chain-of-custody tracking. 

• More than 50% of 2012 Green-e Energy 

certified retail sales used a tracking system.
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EPA Green Power Partnership Strongly Encourages ThirdParty Certification

• EPA’s Green Power Partnership encourages 

organizations to purchase renewable energy. The 

GPP has more than 1,400 Partners, ranging from 

Fortune 500 companies to local, state, and federal 

governments, to colleges and universities. The GPP 

has minimum requirements to participate, such as 

the level of renewable energy purchasing.

• The GPP does not require the use of tracking 

systems or a third-party audit, but “...strongly 

encourages Partners to buy green power products 

that are certified by an independent third-party as 

a matter of best practice.”

http://www.epa.gov/greenpower/buygp/certified.htm
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Double Counting

• Third-party verification can provide assurance that RECs were not double 

counted and that non-energy benefits are included. Double counting occurs if 

RECs are used in both the voluntary market and to meet a renewable portfolio 

standard (RPS), or by two parties in the voluntary market. 

• Double counting is a concern because if two parties each claim to be using the 

same renewable energy represented by a REC it undermines the credibility of 

RECs as a certification of renewable energy use – just as two people owning 

the exact same stock certificate would undermine the credibility of stocks as a 

certification that the bearer owns a share of a company.

• Tracking systems, through their governing documents, help address double 

counting by ensuring that RECs are not double counted within the REC tracking 

systems.
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Environmental Attributes and RECs

• Most tracking systems provide means to ensure that the right to claim 

“environmental attributes” of a renewable energy generator are conveyed 

with the REC. Environmental attributes are the non-energy characteristics 

of a generator, including, for example, the direct emissions from the 

generator.

• If a generator is covered by a cap-and-trade system for a pollutant (criteria 

pollutants or carbon dioxide), that pollutant might not be included as an 

avoided emissions benefit in the associated REC. 

• Worldwide, in most regions with a cap-and-trade system, a REC would not 

include the capped environmental attribute, because the cap does not 

adjust for REC purchases. Because overall emissions in the region are 

capped, purchasing a REC will not reduce GHG emissions because other 

sources make up for any change from renewable energy.

• However, California’s AB32/Cap-and-Trade program and New England’s 

Regional Greenhouse Gas Initiative do contain provisions to ensure that 

carbon benefits are retained by voluntary purchasers by adjusting the cap 

downward to account for the carbon impacts associated with RECs – 

buying a REC does lower GHG emissions via the cap adjustment.
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REC Definitions Provide Clarity

• REC definitions that explain the treatment of 

environmental attributes have been developed by 

Green-e and REC tracking systems.

o For the purposes of Green-e Energy, a REC must contain all 

of the environmental attributes associated with a unit of 

renewable generation, with the exception of cap and trade 

pollutants. See the Green-E Energy National Standard: 

http://www.green-e.org/getcert_re_stan.shtml#standard. 

o North American Renewables Registry (NAR) Whole 

Certificate: A Whole Certificate is one where none of the 

Environmental Attributes have been separately sold, given, 

or otherwise transferred to another party by a deliberate 

act of the Certificate owner. See the NAR Operating 

Procedures: http://narecs.com/resources/index.htm.
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All Tracking Systems Address Double-Counting; All Except NCRETS Ensure that Non-Energy Benefits are Not Sold Separately 

Tracking 

System Ensures against double-counting

Ensures non-energy 

benefits are not sold 

separately

WREGIS 

Written into operating procedures: To ensure that double-counting does not 

occur, generating units participating in WREGIS must report 100% of their 

generation output from that generating unit in WREGIS. In order to register a 

generating unit in WREGIS, the account holder must attest that this unit is not 

registered in any other registry.

Yes

M-RETS 

Written into operating procedures: To ensure that double-counting does not 

occur, generating units participating in M-RETS must report 100% of their 

generation output from that generating unit in M-RETS. In order to register a 

generating unit in M-RETS, the account holder must attest that this unit is not 

registered in any other registry. 

Yes

NAR

Written into operating procedures: To ensure that double-counting does not 

occur, generating units participating in NAR must report 100% of their 

generation output from that generating unit in NAR. In order to register a 

generating unit in NAR, the account holder must attest that this unit is not 

registered in any other registry. 

Yes

MIRECS

In operating procedures: To ensure that double-counting does not occur, 

Generating Units being registered in MIRECS must have 100% of their output 

tracked by MIRECS.

Yes

NC-RETS In terms of use. Cannot register with another tracking system. No

ERCOT Only systems in ERCOT footprint can participate Yes, but vague

NEPOOL-GIS 

GIS creates a certificate for every MWh of renewable, non-renewable and 

import from an adjacent control area generation, every MWh of conserved 

energy and MA alternative credits which are derived from MWh and thermal 

output. For imports, defined in operating rules.

Yes

PJM-GATS In terms of use, and check with NARR and other tracking systems, since some 

generators outside PJM are eligible in PJM. Yes
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Funding Mechanisms Differ 

• REC tracking systems have different ways to recover their operational 

costs.

• Account holders and generators may pay fees, depending on the REC 

tracking system. 

• However, some tracking systems are set up so that generators and/or 

purchasers pay nothing; fees are paid by utilities to cover the costs (see 

following two slides for details).
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Fees for Account Holders and Retirements

Tracking 

System

Annual fee for account holders Fees for REC retirement

WREGIS $1,500 $0.005/REC to issue or transfer, $0.01/REC to retire, 

reserve, or export voluntary REC

M-RETS General account ($2000 annually), Retail Purchaser account 

($1000 annually) $0.005/REC to issue, $0.015/REC to retire

NAR

Project account ($250 one-time registration), general account 

($750 one-time registration, $2,000 annual subscription), retail 

purchaser account ($1,000 annual subscription)

$0.05/REC to issue

$0.01/REC to transfer

$0.10/REC to retire

$0.05/REC to export

MIRECS

Project account ($250 one-time registration), general account 

($750 one-time registration, $3,000 annual subscription), retail 

purchaser account ($1,000 annual subscription), Non-profit 

wholesale power provider account ($500 one-time registration, 

$1000 annual subscription ), additional fees for electric service 

providers.

None 

NC-RETS Fees paid by electric power suppliers based on retail sales $0.01/REC to export

$0.01/REC to retire voluntary REC

ERCOT No fees None 

NEPOOL-GIS Fees paid by electric power suppliers based on retail sales None

PJM-GATS Fees paid by electric power suppliers based on retail sales $0.01/REC to retire voluntary REC

$0.10/REC to retire for RPS compliance

WREGIS Fee Matrix and Definitions, under Join WREGIS: http://www.wecc.biz/WREGIS/Documents/Forms/AllItems.aspx

M-RETS http://m-rets.org/resources/TOU-Appx-A-edited-for-2013-fee-reduction.pdf

NAR: http://narecs.com/resources/downloads/NAR-Fee-Schedule_October2012.pdf

MIRECS: http://www.mirecs.org/resources/MIRECS-Fee-Schedule.pdf

NC-RETS: http://www.ncrets.org/resources/downloads/NCRETS-Fee-Schedule.pdf

PJM-GATS: http://pjm-eis.com/~/media/pjm-eis/documents/appendix-a-gats-fees.ashx
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Fees for Generating Units Vary

Tracking 

System Fees for generating units

WREGIS $200 (Micro), $250 (Small), $850 (Medium), $1,500 (Large)

M-RETS Micro-generator project account ($100 annually), Small generator project account ($250 annually), Project 

account ($500 annually)

NAR

$50 annually (Micro - <40kW), $500 annually and $250 one-time registration (Small – 40kW-<1MW), $1000 

annually and $500 one-time registration (Medium – 1 MW-<10MW), $2,000 annually and $1,000 one-time 

registration (Large - ≥10 MW)

MIRECS

$100 annually and $50 registration (Micro - <40kW), $250 annually and $100 one-time registration (Small –

40kW-<1MW), $750 annually and $350 one-time registration (Medium – 1 MW-<10MW), $1500 annually and 

$750 one-time registration (Large - ≥10 MW)

NC-RETS None

ERCOT None

NEPOOL-GIS None

PJM-GATS Annual fees: $1,000 large brokers/traders/RE generators (>10MW); no fee for residential homeowners and 

aggregators with nameplate <10MW)
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Generator Size or Type Restrictions

• There are no restrictions on the size of 

generators eligible to participate in a REC 

tracking system.

• Third-party “aggregators” can handle REC 

tracking system registration and data inputs 

for multiple small renewables systems

• If a renewable electricity technology is not 

currently being tracked, it can easily be 

added to a REC tracking system.
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Use of Thermal RECs

• Some state renewable portfolio standards (RPSs) allow for 

the use of thermal resources.

• Standards for measuring thermal output are in 

development. Once the thermal output is measured, it 

can be converted to an electric (MWh) equivalent.

• REC tracking systems are beginning to include thermal 

RECs. For example, PJM-GATS tracks solar thermal RECs 

used in Maryland and New Hampshire is developing a 

thermal REC program.

o In Maryland, solar thermal systems must be certified by the SRCC OG-300 reporting 

protocol or have an International Organization of Metrology compliant meter. For more 

information, see http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=MD55F.

o New Hampshire legislation (SB 218) created a new renewable energy Class I subclass for 

thermal renewable energy under the New Hampshire RPS and the NH PUC is currently 

developing rules for accepting thermal RECs used to comply with the new subclass 

requirement. For more information see 

http://www.puc.state.nh.us/sustainable%20Energy/Class%20I%20Thermal%20Renewable%20Energy

.html.
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Contact information:

Jenny Heeter

Renewable Energy Analyst

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, Colorado 80401

jenny.heeter@nrel.gov

303-275-4366