GHG Accounting in the Power Source Disclosure Program

Oct 25, 2018


Near Zero submitted a comment letter to the California Energy Commission on its AB 1110 Implementation Proposal for the Power Source Disclosure Program.

In our view, the proposal would make important improvements to the way California tracks electricity, greenhouse gas emissions (GHGs), and renewable energy credits (RECs). In particular, we appreciate the interest in distinguishing between electricity, GHGs, and RECs to reflect the GHG emissions profile of electricity that serves California load—although we would encourage the Commission to include as much temporal granularity in the GHG emissions accounting as is practicable, both in the current proposal and in any future updates.

Our comments focused on two issues:

1. The default GHG emissions factor for unspecified electricity is based on outdated data and may not accurately represent the emissions associated with unspecified power deliveries to California.

2. Accounting for GHG emissions from the CAISO Energy Imbalance Market raises additional complexities that should be monitored going forward.


Download the full comment letter (pdf).

submitted to the California Energy Commission

Danny Cullenward *†, Mason Inman *, and Michael Mastrandrea *†

* Near Zero

† Carnegie Institution for Science, Department of Global Ecology