Tag: ZEROgrid

Newly launched VERACI-T taskforce will support better electricity emissions data

The new working group is developing standardized, objective approaches to verify the accuracy of marginal electricity emissions data and will make all outputs freely available to the public to jumpstart more effective climate action.

Oakland, Calif. – 27 March 2025 – VERACI-T (Validating Emissions Rates for Accurate Consequential Impact Taskforce), a new working group dedicated to advancing rigorous validation of the accuracy of marginal electricity emissions data, has announced its formal launch, along with the submission of three papers under academic peer review that develop and apply different techniques to evaluate the accuracy of different marginal emissions datasets.

Marginal emissions data are used today in nearly every analysis of the consequential impact of electricity interventions. Corporate practitioners, policymakers, and others evaluating the potential use of different marginal electricity emissions datasets need scientifically accurate, fact-based ways to evaluate the correctness of such data, preferably in a standardized fashion. But today, there is no such standardized approach, and many practitioners in the corporate electricity community are unaware that reliable methods to evaluate such data already exist. VERACI-T is addressing this blind spot to support institutions of all kinds in having ready access to methods that help determine whether and when marginal emissions data are accurate.

The working group is organized as a forum that invites different academics and grid operators to share expertise with one another and with interested corporations. Techniques to analyze counterfactuals to evaluate the accuracy of marginal data are commonplace in many fields, from medical trials to public policy to epidemiology and quantitative finance. The VERACI-T working group operates by finding validation methods that have been widely used and proven to be accurate in other settings, and by developing proposed ways to apply them to marginal electricity emissions data. Members and guest experts then explore and refine such methods before submitting them to peer-reviewed journals for additional third-party verification. All results are freely available for anyone to use to explore the accuracy of any marginal electricity emissions dataset.

“Randomized controlled trials and natural experiments are used by thousands of experts daily in evaluating the accuracy of marginal/causal signals in everything from vaccines to quantitative finance. But all too often in electricity, people assume that regular math doesn’t apply and causal data can’t be validated,” said Gavin McCormick, founder and executive director of WattTime. “The idea of VERACI-T is to help connect anyone still making these assumptions with the same careful, rigorous, peer-reviewed experiments to evaluate accuracy that are used in so many other fields.”

VERACI-T fills an important gap in the growing marginal emissions data space. It complements several other initiatives, such as the ZEROgrid Initiative, an RMI-coordinated coalition that asks academics to weigh in on the carbon accounting and strategic implications of different datasets. The Emissions First Partnership — a group of leading electricity users who have proposed to move beyond megawatt-hour matching to focus on the quantified emissions impact of electricity consumption and generation — is also keenly interested in the question of how to determine when a dataset does or does not accurately quantify such impacts.

VERACI-T is structured as a taskforce in which each member contributes meaningfully to the work. Founding members include Amazon, Apple, Meta, Microsoft, REsurety, and WattTime. So far, environmental tech nonprofit WattTime, energy analytics company REsurety, and two pending future members have gathered and crunched data. Every member, guest academics, and grid operators involved have assisted in reviewing methods to help ensure they are strictly objective. Amazon, Meta, and Microsoft are the initial funders of the working group, and sometimes bring the group particular questions about accuracy for which they are seeking answers.

VERACI-T’s work is conducted one paper at a time, each of which applies a new method to validate the relative accuracy of different types of marginal emissions models. Each paper is then submitted for peer review in traditional journals. The taskforce’s first paper examines claims that different operating marginal emissions models make that are directly observable. The second and third papers examine natural experimental “shocks” in which electricity demand changed unexpectedly to determine whether different marginal emissions models could accurately quantify the change in emissions due to the shock. Future papers will use similar empirical methods to validate the accuracy of long-run emissions models, conduct randomized controlled trials, and compare outputs with non-public grid operator data.

All VERACI-T findings — including validation methodologies, assessment of specific marginal emissions datasets, and other insights and resources — are freely available to the public at https://veraci-t.org/.

VERACI-T’s founding members encourage interested parties to reach out to discuss contributing to the group’s work. This includes academic and other experts in marginal emissions data; groups with access to rare or non-public data that can be used to validate marginal emissions data, like grid operators and utilities; potential funders; and anyone else who would like to learn more.

For more information, please contact VERACI-T’s program coordinator, Chiel Borenstein, by emailing [email protected].

About VERACI-T

VERACI-T (Validating Emissions Rates for Accurate Consequential Impact Taskforce) is a working group of organizations that are developing a framework for validating marginal emissions datasets; investigating how well specific such datasets reflect real-world consequential impact; and assessing and comparing the accuracy of different marginal emissions datasets. Outputs are freely available to the public in an effort to jumpstart more effective climate action. VERACI-T’s current members include: Amazon, Apple, Meta, Microsoft, REsurety, and WattTime. Each meeting, the group invites one new company, academic, or grid operator to join.

Media Contacts

Nikki Arnone
Inflection Point Agency for VERACI-T
[email protected]

Carbon Impact of Intra-Regional Transmission Congestion

Solar Energy Power Grid


Derived from the scientific paper: Carbon Impact of Intra-Regional Transmission Congestion, which received unanimous support from the ZEROgrid Independent Advisory Initiative advisors (MIT Energy Initiative, Princeton, WattTime, and REsurety). To access the study, please scan the QR code.

Overview

The emissions intensity of electricity can vary greatly within grid regions at any given time due to transmission congestion, yet current environmental policies and carbon accounting frameworks typically ignore these differences. By overlooking transmission constraints, these policies risk increasing system-wide emissions and worsening grid congestion, even when consumption and carbon-free energy are matched hourly. A notable portion of new wind and solar capacity proposed for ERCOT and PJM is planned in areas with substantial congestion (Fig. 1), but without significant transmission expansion, these projects will exacerbate congestion and limit emissions reduction. Through several case studies, we find that congestion-aware emissions metrics, such as Locational Marginal Emissions (LMEs), can more accurately measure the carbon impact of clean energy procurement and enhance market signals to support better grid planning and procurement strategies.

Key takeaways:

  1. Transmission congestion has a significant impact on price and emissions for the power grid.
    a. For example, in 2022, transmission congestion in ERCOT increased system cost by $2.8 billion and system emissions by 13 million tonnes CO2e, which is 8.7% and 7.5% of the system total respectively.

  2. In the same grid at the same hour, different locations frequently observe a difference in emission intensity of hundreds of tonnes of CO2e due to transmission constraints.
    a. Even 100% hourly matched consumption with clean energy is often not carbon-free and, in many instances, hourly matching can actually increase operational emissions relative to annual matching (Fig. 2).
    b. Hydrogen production that complies with the current proposed 45V criteria will often significantly increase real-world emissions.

  3. Current carbon accounting methods overestimate emissions reductions by overlooking intra-regional transmission congestion.
    a. Granular emission data, such as Locational Marginal Emissions rates, incorporate transmission impact, providing a more accurate measurement of the real-world carbon impact of grid connected projects.

  4. Transmission planning and infrastructure expansion must be accelerated to achieve the decarbonization potential of renewable energy development.
    a. Clean energy procurement that utilizes marginal emissions rates to inform citing will better incentivize the development of projects in areas of uncongested transmission.
Figure 1:  Contour map of 2023 average LME by county across ERCOT and PJM, with the combined wind and solar interconnection queue for each county (gray circles) overlaid.
Carbon Impact

Figure 1:  Contour map of 2023 average LME by county across ERCOT and PJM, with the combined wind and solar interconnection queue for each county (gray circles) overlaid.

Scope 

This work uses nodal LME data for the past five years in ERCOT and PJM to quantify the effects of congestion on carbon emissions and the efficacy of annual- and hourly- matching carbon accounting frameworks. The impact of intra-regional congestion is shown to be a vital component of effective carbon accounting methods and complementary policies, and policy proposals that frequently overlook this impact risk significantly increasing real-world emissions despite the operational and cost burdens of compliance with hourly matching.

Figure 2: Map of load and procured power from four different renewable project options in PJM; 2023 net emissions from matching scenarios where both rigorously hourly-matched load through load-shifting and 100% annually-matched flat load have significant net emissions.
Carbon Impact
Figure 2: Map of load and procured power from four different renewable project options in PJM; 2023 net emissions from matching scenarios where both rigorously hourly-matched load through load-shifting and 100% annually-matched flat load have significant net emissions.
Carbon Impact

Figure 2: Map of load and procured power from four different renewable project options in PJM; 2023 net emissions from matching scenarios where both rigorously hourly-matched load through load-shifting and 100% annually-matched flat load have significant net emissions.

Assuming equal emissions and perfect generation deliverability within a grid region misses a major factor in determining the induced and avoided carbon emissions, respectively, of load and renewable generation. The induced emissions of a newly built load could be reduced by hundreds of kgCO2e/MWh just by siting it in Eastern Pennsylvania instead of Virginia, for example, and a Virginian wind farm could avoid 50% more carbon than an equivalent farm in Northern Illinois. Prioritizing and incentivizing the development of new renewable projects in less congested regions could meaningfully expedite grid decarbonization, and avoid the exacerbation of already existent congestion-driven deliverability issues.

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Paper: Carbon Impact of Transmission Constraints

Carbon Impact of Transmission Constraints
Zerogrid

This paper is authored by REsurety’s Sarah Sofia and Johns Hopkins University’s Yury Dvorkin. Read the abstract and download the full paper below.

Abstract

Carbon accounting frameworks guide policy and decision-making around investments in renewable energy, making them critical to understand in the context of real-world grid operations. In the absence of empirical work assessing the effects of intra-regional congestion on carbon emissions, ongoing policy design assumes that transmission congestion within grid boundaries can be ignored. In this work, we aim to test this assumption by quantifying the frequency and severity of intra-regional congestion and its impacts on carbon emissions and prominent carbon accounting frameworks. This analysis is done in both PJM and ERCOT using nodal locational marginal emissions data. Through several case studies, we find that load that is 100% hourly-matched through load-shifting will often result in significant net operational emissions, and sometimes even increase net emissions relative to annual-matching. This work demonstrates that, in the absence of robust transmission expansion, grid-region boundaries are insufficient to ensure hourly-matching is effective. Impacts of intra-regional transmission congestion are shown to be vital components of effective carbon accounting frameworks, calling into question frequently made assumptions ignoring intra-regional congestion in studies and policy proposals.

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Policy Brief: Assessing the Impact of Voluntary Actions on the Grid

A Consensus Paper from ZEROgrid’s Impact Advisory Initiative, published by RMI and ZEROgrid

Assessing the Impact of Voluntary Actions on the Grid

Executive Summary

Over the past 10 years, voluntary procurement of clean energy by corporations has been a tremendous driver of renewable energy development. Since 2014, large companies have signed procurement contracts supporting the development of over 70 gigawatts of renewable energy in the United States,1 in addition to purchasing renewable energy certificates (RECs), providing tax equity financing, and advocating regionally and nationally for more clean energy deployment. These voluntary procurement trends are continuing to scale and expand into other markets such as Japan, South Korea, and Taiwan.2

The urgency of the climate crisis is prompting many large energy consumers to consider how they can assess the impact of various actions on grid decarbonization and reliability. Such an assessment can be best made using consequential emissions impact analysis, which employs various approaches to estimate the difference between total global emissions in different possible states of the world.

Although many authors have published on consequential emissions impact analysis, there have been different views and until now no joint statement from differing authors on areas of consensus and how to resolve discrepant conclusions.

To provide greater clarity to corporate actors, ZEROgrid created the Impact Advisory Initiative, or IAI. The IAI comprises a group of expert practitioners from the National Renewable Energy Laboratory (NREL), Princeton University, REsurety, RMI, and WattTime who collectively identified key points of consensus as well as areas requiring further research.i

This paper provides an overview of the IAI’s findings regarding emerging areas of consensus about consequential emissions impact analysis, its implications, and areas where further research is required.

Areas of Consensus:

  1. Defining Impact. The true impact of any voluntary corporate action (or any action) is the difference in total emissions between a world where the action was taken versus one in which it was not taken.
  2. Components of impact. This impact is the sum of several different contributing effects, which must include the effects over the lifetime of the intervention — how an intervention changes the short-run operations of power plants, and structural change, i.e., how it changes the total supply of different power plants in the long run — to fully capture the impact of an action.
  3. Estimates versus true values. The field has a number of ways to produce estimates of total emissions impact and its components. Although there is agreement regarding how changes to short-run operations can be quantified, the field currently lacks — and indeed may always lack — any generally accepted way to empirically verify estimates of structural change. Therefore, any approach that seeks to measure total impact has (potentially significant levels of) uncertainty.

i The ZEROgrid initiative brings together a group of corporate actors, including Akamai, General Motors, HASI, Meta, Prologis, Salesforce, and Walmart, seeking to drive deep decarbonization alongside increased power grid reliability and affordability, working in collaboration with emissions and reliability experts. Additional information is available at https://zerogrid.org/.

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