Studies & Reports
Greenhouse Gas and Clean Energy Accounting Methodology Catalog
This study presents a catalog of Greenhouse Gas (GHG) and clean energy accounting methodologies in use across the Western U.S., inclusive of practices used under Renewable Portfolio Standards (RPS); energy supply mix disclosure programs; mandatory GHG reporting and reduction programs; and voluntary utility and end-use consumer reporting. This catalog aims to provide a representative, but not necessarily comprehensive, description of the GHG accounting practices in use today by utilities across the West, and is derived from a combination of detailed interviews with 15 participating utilities; program information provided by participating utilities; public documentation of required accounting practices under the various programs; and our own research.
Achieving Western States GHG Reduction Objectives
Many states are embarking on aggressive state policies aimed at reducing GHG emissions, with particular attention aimed at largely or fully reducing GHG emissions from the electricity sector over medium-term horizons (e.g., by 2040). The regulatory compliance design will have impacts on electricity markets and the effectiveness of the policies. To analyze different regulatory approaches and their impacts on electricity market participation, the Public Generating Pool, in collaboration with PacifiCorp, sponsored a study by The Analysis Group.
The study considers and compares the impacts associated with resource-based accounting, which focuses on the procurement made by the utility, versus flow-based accounting, which focuses on tracking the electricity flows and delivered energy to customers. The comparison of the two approaches led to several conclusions regarding compliance systems for state-level decarbonization policies:
Physical realities of the electricity system make flow-based, source-to-load tracking of attributes or emissions infeasible, impractical, or inefficacious.
Resource-based accounting is compatible with market-based transactions, thus supporting the evolving market structures that will be important for the feasibility and cost-effectiveness of decarbonization policies.
Resource-based accounting offers more compliance flexibility, particularly with regard to the electricity delivery timing.
Resource-based systems are less administratively burdensome and can draw on experience from approaches used for compliance by states with RPS policies in the Northeastern and mid-Atlantic US.
Flow-based systems are not currently used anywhere in the US. Variants of a resource-based system are used in other jurisdictions in the US.
Consideration will need to be given to how to integrate compliance with RPS/CES policies and emissions-based policies.