Green Power Purchasing Frequently Asked Questions (FAQ)

Clean Energy Purchasing FAQ

This clean energy purchasing Frequently Asked Questions (FAQ) guide addresses complicated issues in greenhouse gas (GHG) emissions accounting and reporting with respect to green power purchasing claims by electricity end-use consumers.

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Many companies make green power purchasing claims with the expectation of reporting lower GHG emissions in their corporate GHG emissions inventories (i.e., their corporate “carbon footprints”).1 While accelerated policy and financial support for renewable energy deployment is urgently needed to help address climate change, it is also critical to the legitimacy of greenhouse gas (GHG) disclosures that emissions be calculated and reported on the basis of credible assumptions and methods that are a true accounting of environmental outcomes.

This FAQ resource uses an evidence-based approach. It especially focuses on Renewable Energy Certificate (REC) and Guarantee of Origin (GO) and their application to corporate (organizational) GHG accounting. These certificates are the dominant instrument used by consumers to make green power purchasing claims and associated zero GHG emission reporting claims (associated with Scope 2 or indirect GHG emissions from the consumption of grid-supplied electricity). The question of the role of Power Purchase Agreements (PPAs) in GHG accounting is, unfortunately, lacking in evidence-based research. Once such research is completed, it will be subject of future updates to this FAQ.

This FAQ addresses voluntary clean energy purchasing claims.2 It does not address compliance tracking and reporting by electric utilities (i.e., Load Serving Entities) that employ certificates under a regulatory mandated clean energy or renewable portfolio standard policy.

  1. U.S. EPA. The Benefits and Costs of Green Power. Guide to Purchasing Green Power.   ↩︎
  2. The fundamentals of GHG accounting discussed in this FAQ applies to other types of voluntary certificates such those for “green gas” or “renewable gas”. Additional commentary here. ↩︎

What is a green power purchase?

What is a REC or a GO?

What am I receiving if I buy a voluntary REC or GO?

Does buying a REC or GO mean I am using renewable energy?

Should RECs or GOs be used for GHG emissions accounting?

Should RECs or GOs be used in carbon footprinting?

Should RECs or GOs be used to support “carbon neutrality” or “net zero” claims?

Further questions related to attributional claims

Should the “location-based” or “market-based” method be used to estimate corporate Scope 2 GHG emissions?

Is purchasing RECs or GOs from a local generator better than from a far-off generator for GHG accounting purposes?

Does the use of a “residual mix” grid emission factor solve the problems with RECs and GO for GHG accounting?

Why have RECs and GOs been widely used in corporate carbon footprints?

Further Questions Related to Consequential Claims

Does my RECs or GOs purchase influence how much renewable energy is generated?

Doesn’t the exclusion of legacy RE and hydropower generation from the voluntary REC market address GHG accounting problems?

If more companies purchase RECs and GOs, then won’t this increased demand eventually cause more renewable energy investment and generation?

What is the difference between a REC/GO and a carbon offset credit?

Is “additionality” relevant or necessary for RECs and GOs to be used in consequential GHG accounting?

Further Questions Related To RECs and GOs

What are the “environmental benefits” or “attributes” associated with RECs and GOs?

Why are RECs and GOs typically so inexpensive?

Does verification or certification of my REC or GOs assure its impact and environmental integrity?

Could hourly RECs or GOs make them appropriate for GHG accounting?

Further Questions Related To PPAs and Other Options

Am I purchasing green power through a PPA?

Can I use my electric utility’s green pricing or green tariff program for my GHG accounting?

What does it mean for an electricity generator to “deliver” electricity”?

Should companies not even attempt to “purchase” green power?