Why hydro-dominated grids can have surprisingly high marginal emissions rates

What do Norway, Sweden, Quebec, and the US Pacific Northwest all have in common? They have grids with significant hydro capacity. In fact, over 90% of Quebec’s electricity generation comes from hydro.

Hydro is commonly considered one of the cleanest sources of electricity — it emits no CO2 during generation1 — so it may be tempting to assume that grids dominated by hydro generation would have a relatively low marginal emissions rate.2 And yet, we find that in these predominantly hydro-powered regions, the marginal emissions rates are high, sometimes even as high as those of their fossil-fuel-dominated neighbors.

Why? It all boils down to whether consuming more electricity causes hydro to produce more electricity — and this usually isn’t the case.

In this article, we’ll explain the mechanics of how hydro-dominated grids respond to changes in demand, what that means for CO2 impact, and why this can lead to higher-than-expected marginal emissions rates in otherwise clean grid regions.

Types of hydro power

Hydropower plants differ by how they manage their water flow and storage, and they largely fall into these four categories:

Of these types, reservoir hydro provides the most energy generation capacity worldwide, so when we generalize using the term "hydro," we are referring to reservoir hydro.  And when we cite aggregated hydro generation in a region, it is also typically dominated by reservoir hydro.

Hydro is a finite resource

There is a fixed amount of electricity (MWh) that any type of hydro generation plant can produce in a given year based on the amount of rainfall, snowmelt, and other water flowing into the dam. If electricity demand increases above what can be provided by the hydro resource, then the additional power will have to come from other resources, typically fossil generation, since they can simply purchase more fuel. 

For example, here is a simplified annual case: Let’s say there is a region similar to Washington State that has 100 TWh of annual electricity demand. Of this, about 60 TWh comes from reservoir hydropower, and the remaining 40 TWh comes from fossil fuels and other sources. Because hydropower depends on water availability, if annual demand grows by an extra 5 TWh beyond this total, that new demand would have to be met by fossil fuels or other dispatchable sources (40 -> 45 TWh), since the annual hydro output is dependent on rainfall, not the operator’s decisions (fixed at 60 TWh).

This concept is observed in the real world during drought years, when total hydro output is reduced. A 2024 International Energy Agency (IEA) analysis concluded that “an exceptional shortfall in hydropower due to extreme droughts – in China, the United States and several other economies – resulted in over 40% of the rise in emissions in 2023 as countries turned largely to fossil fuel alternatives to plug the gap.” And new analysis published just weeks ago by researchers at the Norwegian University of Science and Technology are similarly sounding the alarm for Europe’s power grids: “when droughts strike, hydropower and other renewables don’t work as well as they might. As a result, countries have to fire up more fossil fuel power plants…”

Reservoir hydro’s opportunity cost

Unlike many other generation sources, reservoir hydro has an opportunity cost. Since the water that accumulates behind the dam (and the MWh that can be generated) is finite, if some is used now, it can’t be used later. Because the amount of water inflow into the reservoir isn’t something in our control, generally, hydro plant operators must manage their output. If the operator used whatever water was available right away, the hydro plant would have less capacity later in the year to meet electric demand (because the reservoir level would be lower). Later, when there’s less hydro power available, the grid needs to turn to another fuel source — likely a fossil source — to serve its load. The emissions from burning that other fuel source to serve the grid load are the real marginal impact of consuming additional electricity on a grid with hydro resources.

This might be surprising because it isn’t very obvious if you look at any one particular day. In hydro-dominated regions, you will see that hydro generation generally increases when grid demand increases, as generation roughly follows the load. Intuitively, this load-following behavior is characteristic of typical marginal generators (which respond to changes in load and, in some cases, set the marginal price in the electricity market). However, even if the hydro is the market’s marginal resource, that doesn’t mean it is marginal from an emissions perspective.

Avista Corporation electricity generation by energy source 2/6/2026 - 3/6/20206, Pacific Time

If grid load increases at 4:00 pm on a Friday, then hydro might be able to ramp up to satisfy that demand. But, that also means there’s less water available to generate electricity to meet the load at a later hour, say 5:00 pm the following Monday. Fossil fuels still end up serving the extra load from 4:00 pm that Friday, it’s just that they are burned at a later time (in this case at 5:00 pm Monday).

Avista Corporation electricity generation by energy source 2/6/2026 - 3/10/20206, Pacific Time

So even though the daily pattern can show hydro following load, when you look more broadly at a full week or more, a different story is revealed: increasing hydro generation in one hour simply means increased fossil usage at a later time.

Abrell & Kosch (2022) detected this empirically in Sweden and Germany, stating that “while at the hourly level RE replace a substantial amount of hydro generation, it is likely that in the case of reservoirs and pump-storage plants, this generation is shifted to another hour of the same week. This increase of hydro generation in other hours then replaces fossil generation and leads to an additional offset of carbon emissions. This effect cannot be observed at an hourly level, but is only accounted for when re-sampling the data to weekly values.”

This demonstrates how reservoir hydro is not actually marginal from an emissions standpoint. Even though its output can be dispatched up and down with load fluctuations, over longer periods the output cannot be increased for any reason other than that more rain fell and accumulated behind the dam. 

Grid balancing via interchange

Due to hydro’s finite annual capacity, grids with hydro often coordinate with their neighbors to balance supply and demand. Let's look at Sweden and Germany. Sweden has a hydro-heavy grid and is generally a net exporter of electricity to neighboring countries, including Germany. However, when Germany often has a surplus of wind or solar generation, it sometimes exports that energy to Sweden. Research on cross-border electricity flows shows that when this happens, German renewable generation displaces Swedish hydro — effectively freeing up that stored water for use at other times or in other markets. 

The same logic works in reverse: if demand goes up in Sweden, it exports less hydro to adjacent grids, and those adjacent grids may then have to turn to coal or natural gas to meet the demand previously supplied by Swedish hydro. So, even though Sweden’s grid is clean, a rise in domestic demand causes a fossil plant to ramp up somewhere, just not within Sweden.

Ultimately, this shows how dirtier resources in neighboring grids often set the marginal emissions rate for hydro regions, which is why we see higher-than-expected marginal emissions rates in those hydro-dominated regions.

Hydro as a water battery?

As we’ve seen, a grid operator can use hydro instead of burning fossil fuels, but later will need to burn more fuel to allow the reservoir to refill.  Functionally, this ability to time-shift when fossil fuel power is needed means that reservoir hydro essentially acts like a battery (similar to its pumped-hydro storage cousin), allowing fossil-fuel generation to be shifted in time and even across grid boundaries.

A reservoir hydro “battery” can also time-shift renewable energy to displace fossil power. Bonneville Power Administration (BPA), which operates the US federal hydro system in the Pacific Northwest, is a clear example of this — effectively acting as a giant battery for California. During the day, when California's abundant solar generation exceeds its own demand and much of it is discarded (or at risk of curtailment), BPA imports some of that excess clean power and reduces hydro output. At night, when California's solar output drops but demand remains high, BPA exports power back south, displacing what would otherwise be fossil-fuel generation within the California grid. Every MWh of solar California exports that would have been curtailed is another MWh that can be returned at night to displace would-be fossil generation. As shown in Figure 5 below, this daily cycle is clearly visible in BPA's interchange with CAISO (California's grid operator) over a typical week.

Is hydro ever marginal?

The only way that hydro could be marginal from an operating emissions standpoint is if there is “spillage.” When a reservoir reaches its maximum water level, to prevent damage to the dam, operators must open spillway gates, which redirect water around the dam, bypassing the generating turbines, which would normally turn it into electricity. This spillage can occur if demand is low and the grid cannot accept additional hydro generation without undermining the grid’s system frequency.

In this situation, if demand increases, hydro generation can increase, allowing more water to flow through the turbines to generate electricity rather than bypassing them and being wasted. So the increase in demand is met by hydropower from otherwise-spilled water, meaning the additional demand causes zero emissions.

But, how often does spillage really happen? In the places we’ve found spillage data, the evidence shows us that it is exceedingly rare. For example, BPA data shows that there was only one hour over the past two years in which spillage actually occurred (0.005% of time). We have been unable to locate any data indicating this kind of spillage in other hydro heavy grids, such as Norway, Sweden, Quebec and Paraguay, but please share them with us if you come across these data!

So in theory, hydro can be marginal during spillage, but spillage seems to be so rare that in practice, it almost never is.

WattTime MOERs capture the holistic impact of hydro

Because reservoir hydro effectively functions as a "water battery," it shifts the timing of other dispatchable generation rather than eliminating the need for fossil fuels to balance the grid. In these systems, the true marginal impact of consuming an extra megawatt-hour is not the response of the zero-carbon hydro production at that moment, but rather the fossil-fuel combustion required later, either locally or through an interconnected neighbor.

WattTime's Marginal Operating Emissions Rates (MOERs) capture these dynamics in real-time. WattTime empirically models the full system-wide impact — accounting for whether hydro is truly acting as a marginal resource in a given region, and reflecting imports and exports between regions to capture cases where the marginal generator sits entirely outside the local grid. As an example, BPA’s MOER heatmap for 2025 is shown in Figure 6, showing that for most hours of the year, from an emissions perspective, the marginal fuel is natural gas-fired generation (mostly from within California), with an emissions rate of roughly 1,200 lbs/MWh.

Fig-X_ BPA_MOER_heatmap_2025

Remember, building a data center or carbon capture facility in the Pacific Northwest, Quebec, or Norway won’t cause more rain to fall there, so it would require generation from a non-hydro resource to meet its additional load. When it comes to planning and decision-making, assuming that a hydro-heavy grid means low emissions impact can lead you astray. You don't need to trace the temporal effects and causal chain through interchange yourself — you just need a marginal emissions rate that accurately reflects those dynamics at the system level. That's what WattTime MOERs are built to provide.

1. We recognize that hydropower reservoirs also emit methane, and the state of the science is still maturing on quantifying the consequential emissions relative to if the reservoir wasn’t built. It’s not yet clear whether the net consequential impact is an increase in emissions. Hydro’s methane emissions are not why a hydro grid has a high marginal emissions rate, because as you’ll see, the carbon intensity of hydro is almost never a factor in determining the marginal impact of load changes in a hydro region. (return to top)

2. Marginal emissions rate means the rate at which emissions are caused by a change in demand on the grid. When demand increases or decreases, a power plant will change its output to keep the grid in balance. The emissions factor of that responding power plant is the marginal emissions rate (return to top).

New North America Data Models Released to WattTime API

TL;DR

What’s new in model ‘2026-03-01’?

We’ve released a new model for all of North America (US, Canada, Mexico), for our CO2 MOER and Health Damage signals (Health Damage is still only available in the US).

More renewable curtailment: As grids reach higher levels of renewable energy, these grids start to turn off and waste some, at times when supply exceeds demand. More regions are now wasting renewables, so we’ve added curtailment detection in these regions. 25 grids in the Western Interconnect have joined the Western Energy Imbalance Market, which enables more efficient interchange between them and creates a signal (LMP price signal) for assessing renewable curtailment that didn’t previously exist. Additionally, one grid in Colorado (PSCO) has joined a similar market, the WEIS, which also provides an LMP price signal. We’re now using LMP data in these regions to infer when curtailment is happening, resulting in MOER values of zero lbs/MWh.

Improved forecast performance: Our research team has made improvements to our ML model selection pipeline, weather input features, and curtailment predictions. The resulting changes are not always dramatic, but we’ve measured improved performance as judged by higher accuracy (lower MAE), higher rank correlation, higher F1 scores (more balanced precision/recall), and increased total CO₂ reduction in load-shifting simulations.

Retrained to reflect grid changes: We’ve retrained the model on newer data so it now better reflects how grids operate today. Electric grids change over time as new power plants or transmission lines are built, old power plants are retired, or new markets are formed - all of these changes affect how a grid operates and responds to loads. For example, between 2021 and 2024, total generation output from coal decreased 27% while natural gas generation increased 18%.

Renewable curtailment values: Prior models applied renewable curtailment probability as a derate factor on the MOER, in some cases resulting in low non-zero MOERs. The new model applies curtailment as a boolean mask (fully applied, or not at all), which means more zero values in places with curtailment.

How will the data be different? MOERs with a zero value due to renewable curtailment will be newly present in 25 grids, and there will be more zero values in regions that already had curtailment. The shifting marginal fuel mix from coal to gas will affect the seasonal and diurnal variation patterns in higher ranges of MOERs in some regions. 

These changes to the range and distribution of values could cause disruptions to your products if you use static thresholds. Please reach out to us if you think the changing data might cause problems, and we can help you understand the changes in more detail and identify solutions. The availability of overlapping data for old and new models allows you to make comparisons and any necessary adjustments.

Overall results? Better CO2 reductions: In one of our standard load-shifting performance simulations (10 kW daily load shifting with a 25% duty cycle for one year), we found that optimizing with the forecast captured 3.1% more of the emissions-reduction potential than the prior model. The same simulation showed that the potential CO₂ reduction opportunity increased by ~25% on average across all regions. Performance improvements were seen in our other simulations as well. Overall, this means that we’re detecting more of the grid’s CO2 swings, leading to bigger potential CO2 reductions, and the improved forecast is enabling more of that opportunity to be captured.

Why do we upgrade data models?

WattTime uses empirical models to estimate emissions from electricity grids. We occasionally upgrade these models to improve the impact and accuracy of our signals. Some reasons why we may deploy a new model include:

When deploying a new model, we issue a new “model date” which serves as the unique identifier in the API. Note that, between model upgrades, we may also simply retrain models on newer data, and when the model output change is less significant, we won’t issue a new model date. These model retrains can be more frequent and are intended to reduce drift between how the grid operates today and how it operated during the historical training period.

How is the new model rolled out?

We support over 1B IoT devices globally, and we roll out new models carefully to avoid potential disruptions. That process has been further refined with this release to provide our partners with a smoother transition when models are upgraded. This section explains the rollout timeline for this model upgrade and serves as the template for model upgrades going forward.

Release timeline

March 4, 2026: The new model ‘2026-03-01’ is available for the CO2 MOER and Health Damage signals. Backfilled data for the new model is available for 2+ years for MOER, and data is generated in real time.

March 18, 2026 (+2 weeks): The new model ‘2026-03-01’ becomes the default. Recurring API calls that use the default model (omit the optional ‘model’ parameter) will automatically switch from returning the prior model’s data to returning ‘2026-03-01’ data. Data is still generated in real time for both the old and new models. Either model can be requested using the optional ‘model’ parameter in API queries.

April 2, 2026 (+2 weeks): The prior model is discontinued, meaning new historical and forecast data will not be generated for it. Data from the prior models for the period prior to discontinuation will still be available. Only data for the new model will be generated going forward.

For API users: To receive data for the newest model version from the API, most users will not need to make any changes to the way they pull data (the API itself is not changing). On March 18, 2026, the new model ‘2026-03-01’ will become the default and data from that model will be returned for requests that omit the optional ‘model’ parameter.  If you’d like to access the data before Mar 18, you must specifically request it by using ‘2026-03-01’ for the model parameter.  If you currently use the optional ‘model’ parameter, be aware that on April 2, 2026, no new data will be produced for the old models being replaced (e.g. 2023-03-01 and 2022-10-01), and any queries specifically for those models for a period after discontinuation will be redirected to the new model.

What’s next? 

We’re excited to share this new, more impactful data with the world. We hope the new model release process provides our users with a smooth transition. We’re also better prepared to retrain our models more frequently so that real-time data more accurately reflects how grids are transforming over time.

We’re open to your feedback on this rollout and how we’ve communicated it. Please reach out if you need any support!

WattTime’s Formal Complaint to the Greenhouse Gas Protocol on the Scientific Merit of its Scope 2 Proposal Claims

Read WattTime’s formal complaint here:
Scientific Accuracy Complaint Against the Greenhouse Gas Protocol’s Proposed Scope 2 Update: The Need for Additionality

In collaboration with leading researchers on carbon accounting, WattTime submitted a formal complaint to the Greenhouse Gas Protocol (GHGP) on January 7, 2026, challenging the scientific merit of the emissions reductions claims underlying its Scope 2 proposal for deliverable, hourly matching. In particular, WattTime has challenged the assumption that the GHGP’s outlined approach will reduce system-wide carbon emissions. 

The GHGP’s vision is “that all private and public entities account for their GHG emissions, enabling an acceleration in reductions in line with the global warming limits required by climate science.” In addition, the GHGP’s Governance Overview identifies supporting “ambitious global climate action and programs” as one of three core criteria guiding decisions on framework revisions — making climate impact a stated driving force of the revisions process. 

Despite these clear goals, the GHGP put forward a deliverable (or local-only), hourly matching framework that lacks an additionality requirement. Additionality — or the concept that procurement meaningfully contributes to new clean energy capacity on the grid — is key to ensuring real carbon impact. 

Overwhelming academic evidence demonstrates that, without an additionality requirement (one of the so-called “Three Pillars”), this proposal will fail to drive emissions reductions further than the current annual matching framework. As a result, the proposal does not align with GHGP’s own stated vision or with established climate science. 

WattTime submitted the complaint under Section 2.2.2 of the GHGP’s Complaints and Concerns Procedure, which states that complaints have merit if they identify “a factual error, outdated scientific assumption, or methodological flaw that can be substantiated with peer-reviewed literature or authoritative sources.” 

In the spirit of transparency and clarity, and for the benefit of all energy and sustainability stakeholders seeking to better understand the potential impacts and limitations of the current GHGP Scope 2 carbon accounting proposal, WattTime is making its formal complaint available for all to review. 

We encourage you to read the complaint using the link below, send us your questions, and continue to engage in the GHGP revision process via the public comment period (now open until January 31, 2026), by submitting complaints, or otherwise making your voice heard.

Read WattTime’s formal complaint here:
Scientific Accuracy Complaint Against the Greenhouse Gas Protocol’s Proposed Scope 2 Update: The Need for Additionality

Note: Additional signatories included here may be speaking in a personal capacity and not on behalf of their employers.

Impact Accounting and Hourly Matching: A Review of the Research into Outcomes

Download the metastudy paper PDF: Impact Accounting and Hourly Matching: A Review

The GHG Protocol is currently considering two different proposals for how emissions from electricity (Scope 2) are reported, which could have significant repercussions on the future of renewable energy purchasing. The two separate proposals are a) local hourly matching, which counts renewable energy only in the same location and hour it is consumed, and b) consequential impact accounting, which counts the total impact on emissions of an action. With corporations purchasing over 270 TWh of renewable energy in 2024, understanding the way that these reporting standards could shape those purchasing decisions is critical for the future of grid decarbonization.

Over the past year, a notable pattern has emerged in discussions convened through the ZEROgrid Impact Advisory Initiative between proponents of hourly matching and those favoring consequential approaches to clean energy procurement. Across these conversations, there was consensus on how to estimate the impact of renewable procurement: the change in total long-run real-world emissions compared with the scenario in which the procurement did not take place, recognizing that this hypothetical counterfactual scenario can often only be estimated but not directly measured. Disagreements were not on the definition of impact, but on how to best achieve impact and whether that emissions reduction impact should be the primary criterion to set an accounting standard around. 

The ZEROgrid Impact Advisory Initiative discussions led to two concrete outcomes. The first was the ZEROgrid white paper, jointly authored by both hourly matching and consequential advocates, clarifying the above definition of success. The second was recognition of a need for what we called the “impact metastudy”, to examine all available research on a single question: what is the effect on this impact of different accounting standards and the procurement methods they promote?

This idea found widespread support in several circles. At the June 2024 NREL/RMI workshop, a group of 30 companies and emissions experts endorsed the need for an impact metastudy. Work from numerous experts, in ZEROgrid and not, is used in the impact metastudy. In September 2025, Climate Breakthrough Foundation selected these kinds of impact metastudies for carbon accounting as one of the five most promising climate breakthroughs of 2025. 

Over the past year, WattTime has conducted work on the aforementioned impact metastudy. This metastudy comprises various studies on the impact of different possible carbon accounting standards. “Impact” is defined consistently with the first ZEROgrid report: reductions in total, real-world, long-run emissions, which are precisely mathematically defined, whether or not we are able to directly measure them.

To do this, we considered existing studies and worked to fill in gaps with new studies. The existing and new studies include: 

A further study, using data from Transition Zero, is also currently under development, so that chapter of this review is still forthcoming.

We used a variety of methods and models to perform these analyses to get a fuller picture of the outcomes of implementing these proposed standards, in order to understand what outcomes these different models agreed on. Today, we are publishing a review summarizing both our research and other relevant publications from other researchers [1,2,3]. Across the studies, we find four robust conclusions: 

These conclusions have strong implications for how a revision to the accounting standards will impact total global emissions. The currently proposed local hourly matching standard is likely to come at a high cost that could reduce total participation in voluntary procurement. Without a stronger additionality constraint, procurement will not lead to actual reductions in emissions. And a local deliverability requirement may reinforce the existing bias towards investing in relatively clean grids in the USA and Europe. By contrast, a consequential impact accounting standard could guide renewable energy purchasing into the dirtiest grids where projects have the most cost-effective impact on reducing emissions. This freedom in location could also lead to an expansion of investment in the Global South, where grids are dirtiest and renewable investment is the lowest today. A consequential reporting standard focused on emissions could provide the strongest signals to voluntary corporate renewable energy purchasers to reduce more global greenhouse gas emissions more quickly.

WattTime would like to especially thank Climate Breakthrough for the majority funding of this research. Thank you also to Apple, Meta Platforms, HPE Foundation, James and Kaye Slavet, and Reid Hoffman for providing funding or support. Thanks to Gurobi for providing access to their linear optimization software. The views expressed in the article do not necessarily represent the views of the sponsors.

Download the metastudy paper PDF: Impact Accounting and Hourly Matching: A Review

If you’re concerned about how the proposed revisions to Scope 2 could negatively impact your business or would just like to share your perspective with the GHG Protocol, they are accepting comments here through January 31, 2026. If you’d like more help navigating the two separate proposals and the two lengthy surveys, we’ve provided more guidance here.

WattTime and REsurety launch free Scope 2 carbon calculator that compares renewable energy claims under hourly matching and impact accounting frameworks

With the Greenhouse Gas Protocol's public comment period now underway, the tool provides corporate stakeholders with straightforward answers on how newly proposed Scope 2 accounting guidelines will directly affect their renewable energy claims.

BOSTON and OAKLAND, Calif., Dec. 1, 2025 /PRNewswire-PRWeb/ -- Environmental tech nonprofit WattTime and REsurety, leading provider of software, services, and marketplace solutions empowering the future of energy, today launched a free, easy-to-use Scope 2 accounting calculator. With the tool, companies can see how their reported and real-world Scope 2 greenhouse gas (GHG) emissions totals would compare under the hourly matching framework recently proposed by the Greenhouse Gas Protocol (GHGP) and an impact accounting approach like the one recommended by its Technical Working Group Consequential Subgroup. It also shows the cost implications for achieving higher emissions reductions under either framework.

The tool provides critical insights and much-needed clarity as corporate clean energy buyers and other key decision makers engage in the GHGP's public comment period, which closes on December 19, 2025.

The core GHGP Scope 2 public proposal includes a local-only hourly matching requirement for inventory accounting, along with a separate proposal for reporting non-supply chain actions using an impact (consequential) approach. These revised guidelines are expected to change not only how organizations report on their emissions, but also incentivize different procurement behaviors as companies attempt to reach ambitious clean energy and climate goals.

Today, however, these proposed guidelines remain largely theoretical to most organizations. Stakeholders need a clear and comprehensive understanding of how GHGP Scope 2 changes will directly affect them. WattTime and REsurety created this carbon calculator to fill that gap. In addition, they designed the tool to look beyond what is included in the GHGP's public consultation for voluntary impact accounting — which only looks at clean energy procurement — to calculate the impact of all activity, including power consumption, to better enable target setting and tracking.

"With the Greenhouse Gas Protocol's Scope 2 public comment period underway, and on the heels of COP30, this tool is coming at a critical moment," said Gavin McCormick, founder and executive director at WattTime. "Our hope is that it helps drive the conversations companies are already having about how they can make the biggest possible climate difference, anchored by facts and tailored to their priorities."

With an impact accounting framework based on comparing induced and avoided emissions, companies track the additional emissions reductions that result from their portfolio investments, making decisions based on the most impactful times and places to generate, procure, and consume electricity.

On the other hand, a local-only hourly matching framework requires companies to match their electricity loads on an hourly basis using renewable energy sources on the same grid as the company's original consumption.

"Corporate energy buyers are making big decisions today that will shape clean energy markets for decades to come," said Lee Taylor, CEO of REsurety. "This tool provides much-needed visibility into the trade-offs between two leading approaches, so they can make informed decisions during the public comment period."

To use the free Scope 2 accounting calculator, visit calculator.gridemissionsdata.io.

If you are interested in learning more about the tool and how it can help your organization engage throughout the GHGP's open comment period, email contact@gridemissionsdata.io.

About REsurety
REsurety is the leading provider of data, software, and services to the clean energy economy, and operates the only transactional marketplace for clean power. Trusted by the industry's leading buyers, sellers, and investors, REsurety's proprietary data models, powerful technology platforms, and deep domain expertise empower confident, impactful decision-making and efficient, effective portfolio management. For more information, visit www.resurety.com or follow REsurety on LinkedIn.

About WattTime
WattTime is an environmental tech nonprofit that empowers all people, companies, policymakers, and countries to slash emissions and choose cleaner energy. Founded by UC Berkeley researchers, we develop data-driven tools and policies that increase environmental and social good. During the energy transition from a fossil-fueled past to a zero-carbon future, WattTime 'bends the curve' of emissions reductions to realize deeper, faster benefits for people and planet. Learn more at www.watttime.org.

Media Contact
Nikki Arnone and Logan Varsano, Inflection Point Agency for REsurety and WattTime, 1 (719) 357-8344, nikki@inflectionpointagency.com, https://calculator.gridemissionsdata.io/

SOURCE REsurety and WattTime

A Global Approach to Renewables Purchasing Could Reduce 370% More Emissions than Local Hourly Matching

This post explains one set of findings from a larger research paper.

The full overview and paper are here: Impact Accounting and Hourly Matching: A Review

Global impact accounting will also redirect corporate renewable investment from the US and Europe to the Global South.

The Greenhouse Gas Protocol is currently considering two proposals to revise the emissions accounting standard for electricity use and renewable energy purchasing. One proposal would add hourly matching & deliverability requirements, meaning that renewable energy could only be counted if matched to the hour and location where electricity is consumed. The other separate proposal describes how to report the consequential impact (the change to total global emissions) of projects, regardless of their time and location (this is also sometimes referred to as impact accounting or emissions matching).

While there have been many studies that investigate the impact of the hourly matching requirement [1,2,3], there has not been an investigation into the global scale impact of the deliverability requirement (procuring renewable energy on the same grid as your load). Most studies have focused on voluntary renewable energy purchasing in the USA or Europe, which have the highest levels of renewable energy purchasing and comparatively low emissions per MWh. However, there are many countries in the world with much dirtier grids but low levels of renewable energy purchasing. Increased procurement of renewables in these countries could provide a much higher impact on avoided emissions per dollar spent, while simultaneously reducing health problems from local pollution and investing in historically under-invested economies.

We studied the impacts on global voluntary renewable energy purchasing that could result from an hourly matching & deliverability standard and separately, from an impact accounting standard. We found that for a fixed cost, impact accounting avoids over 211 MT CO2 per year, 4.7 times more than hourly matching with deliverability.

Methodology and Data

To model this, we simulated procurement portfolios globally under both an hourly matching & deliverable standard (“hourly matching” from here on) and an impact accounting standard. While the GHGP Scope 2 protocol is used globally, it is a voluntary standard that not all companies choose to follow. To estimate the relative levels of participation, we used the amount of purchased renewable energy from the 2024 Corporate Renewable Electricity Sourcing Trends report published by CDP. This report only covers companies that reported their location-based scope 2 emissions to CDP, which serves as a reasonable representation of the distribution of voluntary corporate purchases under the GHGP today. The distribution of historical voluntary purchasing is heavily skewed to the Global North, with the highest levels of renewable energy purchasing in Europe excluding Russia (175 TWh) and the USA (124 TWh). 

We modeled the purchasing decisions using a linear program (LP) method, which optimizes for the least-cost global voluntary energy purchasing of wind, solar, and battery resources subject to local hourly matching and emissions matching constraints. All procurement is assumed to be new build and fully additional. Global technology costs are taken from the IEA’s 2024 World Energy Outlook. We used the capital and operating costs for 2030 under the “Stated Policies” scenario. To annualize the capital costs, we amortized the costs over a 25-year lifetime and apply a 10% additional cost of capital. 

For hourly matching, we added the matching and local procurement constraint for an amount of load equal to the purchased renewable energy in each country (as reported by CDP). For impact accounting, we measure the induced emissions from load and the avoided emissions from renewable projects using the Combined Marginal Emissions Rate (CMER), which is the combined average of the Marginal Build Emissions Rate (MBER) and the Marginal Operating Emissions Rate (MOER). There is no location constraint for impact accounting, so projects can be selected from anywhere on the globe. To ensure that the solutions are reasonable, we add a constraint that the procured projects cannot exceed more than 20% of the total existing capacity from all generators in the country. This guarantees a solution where projects are spread among many countries, instead of concentrated in a single country with a volume that is impractical or unrealistic. If this constraint were removed, the model would concentrate procurement in a few countries with the highest emissions avoidance per cost, further amplifying the advantage of global impact accounting over hourly matching.

Global Impact Accounting Reduces More Emissions Per Dollar

In 2024, corporations procured a total of 562 TWh of clean energy globally. While we don't know the total cost of those clean energy purchases, if those 562 TWh of clean energy were instead procured in locations that maximized their avoided emissions, that portfolio of renewable energy procurement would cost $4.6B and avoid 211 MT of carbon emissions per year. Alternatively, that same $4.6B spent towards a 98% hourly match with local deliverability requirements, would only avoid 45 MT CO2 per year (4.7 times fewer avoided emissions). We chose to compare both strategies at a fixed amount of spending, instead of a fixed level of participation, because hourly matching portfolios are significantly more expensive than impact accounting portfolios. The total cost for a 98% hourly matched portfolio is 16.5 times more expensive than impact accounting. 

While some companies may be willing to pay a premium for reducing their scope 2 accounting, the expected trend is that fewer companies will voluntarily offset their scope 2 emissions as the cost of doing so increases because of basic demand elasticity (we explored this in a previous post analyzing participation vs. costs). Instead of assuming that participation will stay the same regardless of costs, as previous studies have done, we instead assumed there is a fixed budget available for voluntary corporate procurement. For the cost of all participants achieving 100% emissions matching, only 6% of participants could achieve an hourly matching score of 98%. While the exact amount and willingness to pay are not known, the difference in avoided emissions per dollar remains.

This difference in impact can be understood by looking at the average amount of avoided emissions per dollar spent for each strategy: 100 lbs CO2 per $USD for impact accounting vs. 21 lbs CO2 per $USD for hourly matching. These differences in avoided emissions per dollar spent reflect the fact that grids with historically high voluntary RE development are not grids with the highest marginal emissions rates.  Below is a list of the top 10 countries for RE purchasing and the top 10 countries by avoided emissions rate per dollar. The countries with the highest levels of RE purchasing are largely in the US or Europe, but also include China and Brazil. China is the only country with high levels of voluntary RE purchasing to also appear in the list of high-impact countries, which are primarily countries with developing economies in the Global South that have very low levels of voluntary RE purchasing today and high levels of fossil fuel generation.

Below, we also plot the average avoided emissions per dollar for the 5 largest countries by load, along with the average aggregated by region, excluding those 5 countries. Comparing the average avoided emissions per dollar and the level of existing purchases of renewables shows where today’s investing is highly concentrated in locations with low avoided emissions per dollar and locations with more cost-effective impact are underinvested. India and China have an avoided emissions impact of 114 and 99 lbs CO2/$USD respectively, compared with a rate of 34 and 27 lbs CO2/$USD for Europe and USA respectively. The average rates for the Americas and Asia, at 96 and 83 lbs CO2/$USD, are higher than the average rate in Africa of 54 lbs CO2/$USD. The aggregated rates are averages, and the countries inside a region can still have a large spread of avoided emissions rates.

Impact Accounting Directs Investments from the Global North to the Global South

We analyzed the locations where annual RE spending could go under an hourly matching and an impact accounting standard with the same amount of total investment. Under hourly matching, the local matching requirement means investment would be concentrated in the US and Europe, similar to how it is today. Under impact accounting, the optimal distribution of investment today is almost entirely in Asia. This means a dollar invested in Asia will avoid the most CO2. However, investors may prefer other locations when non-climate factors are considered, and they can still choose more impactful locations outside of Asia that aren’t in their local grids. 

A consequential impact accounting standard without a local matching requirement could incentivize companies based in the Global North to purchase renewable energy projects in countries in the Global South for much more cost-effective decarbonization than local hourly matching. This could potentially provide an economic benefit to these countries by creating demand for RE projects, as well as pressuring grids to allow renewable energy purchasing agreements, such as VPPAs, which would make even more RE development possible. In addition to the economic and carbon benefits, many of these countries have very poor air quality from fossil fuel generation, leading to significant health problems and loss of life. A recent study found that air pollution in India increased deaths by 1.5 million per year. Increased development of renewable energy would displace fossil fuel generation in many of these countries, reducing global carbon emissions and improving local health at the same time.

Why Scope 2 Should Embrace a Global Approach to Procurement

Research suggests that local hourly matching in the US and Europe could help reduce meaningful amounts of emissions only at high levels of matching and only if it includes an additionality requirement, which the current Scope 2 proposal does not. However, achieving a high level of additional hourly matching has also been shown to be up to four-times more expensive and might reduce voluntary participation. The local deliverability requirement also has the impact of continuing to concentrate renewable energy investment in the US and Europe, where significant progress on decarbonization has already been made, so adding it would even further erode the emissions reduction effectiveness of the accounting standard. 

A change to the Scope 2 protocol in favor of local hourly matching would undermine the overall effectiveness of voluntary corporate renewable energy purchasing. Local hourly matching is much less efficient than global impact accounting, which avoids more emissions per dollar. Global impact accounting could increase the impact of voluntary renewable energy purchasing in two ways: first, each dollar spent achieves greater emissions reductions, and second, more actors are likely to participate due to the lower costs. In addition, hourly matching would continue to concentrate renewable energy development in regions such as the U.S. and Europe, which already have a strong appetite for grid decarbonization, while limiting investments in countries where benefits are greater.Instead, allowing for impact accounting regardless of location could direct investment to countries that are at the beginning stages of decarbonization. Prioritizing these countries could reduce more emissions while addressing global inequity at the same time. Corporations such as Salesforce, Heineken and Amazon have already begun to purchase renewable energy across Africa, Southeast Asia and Latin America in order to prioritize high impact projects. A change to the Scope 2 protocol in favor of local hourly matching threatens the future of projects like these, since many would not be credited under such a standard. A global consequential impact accounting standard would instead incentivize companies to explore outside of their local boundaries and pursue more impactful projects worldwide.

Analysis: Measuring the Carbon Impact of Battery Energy Storage Systems

Measuring the Carbon Impact of Battery Energy Storage Systems white paper cover with the background image of battery storage

Download the white paper PDF:
Measuring the Carbon Impact of Battery Energy Storage Systems

Executive Summary

As the deployment of commercial-scale battery energy storage systems (BESS) accelerates, companies are seeking a common standard for quantifying the system-wide emissions impact that they cause.Companies that operate BESS are also integrating real-time emissions forecasts as signals to optimize the timing of charge/discharge cycles. To the extent that the goal of this strategy is to measure and reduce CO2 emissions into the atmosphere, both the measurement and control signals must use consequential emissions factors to measure and achieve the desired outcome.

This study assesses an Amazon-enabled BESS in California to demonstrate a practical way of estimating the atmospheric CO2 emissions caused by a BESS (including the system-wide short- and long-run impacts) using freely and globally available data. This study also showed that a battery can be operated to achieve multiple objectives (revenue and CO2 avoidance) by very simply combining both objectives into the control signal. It also shows the high cost that can come from using a CO2 signal that doesn’t measure consequential atmospheric emissions impact (e.g., hourly average emissions rates as used in GHG Protocol Corporate Standard Scope 2 reporting).

Estimating the Impact of BESS is Practical

WattTime analyzed an Amazon-enabled BESS in California as a case study to demonstrate a practical method for estimating the consequential emissions impact of a BESS. We used an approach consistent with well-established guidelines and standards for consequential analysis and emissions factors that are freely and globally available. This approach is accessible to any party operating a BESS today.

BESS Can Achieve Multiple Objectives

We found that when the BESS had been operated to maximize revenue, it also avoided substantial CO2 emissions. This outcome would not occur everywhere; it is more likely in places with surplus renewables whose curtailment aligns with negative wholesale prices.

We also analyzed several theoretical scenarios for dispatching the BESS for multiple objectives. We found that there was significant additional potential to avoid CO2—up to 45% more—by combining emissions and price signals when optimizing the dispatch timing of the BESS (this technique is applicable everywhere, with varying degrees of emissions upside).

Different companies may have different budgets and different ideal outcomes. We demonstrated that the objective outcomes can be balanced by customizing the weight of each. There’s a wide range of CO2 abatement costs, from $45 to $170 per tonne, that achieve better than 85% of the best-case outcomes for both objectives. For example, the BESS could avoid 30% more CO2 emissions, while only giving up 4% of maximum revenue, at an abatement cost of $68 per tonne.


The Risks of Optimizing to Reduce Hourly Scope 2 Footprint

Many companies produce annual carbon accounting inventory reports using the GHG Protocol Corporate Standard under Scope 2 for electricity, using data of annual granularity. For BESS to be reflected in this inventory, hourly accounting is necessary. However, this shift to hourly Scope 2 accounting using an attributional framework could incentivize BESS optimization using an attributional signal (i.e., average emissions rates). There are significant climate, health, and financial risks to companies using this attributional framework to guide operational strategy or decision-making. To quantify those risks, we analyzed the outcomes for a hypothetical case where the BESS was optimized to minimize a Scope 2 carbon footprint, measured hourly.

Optimizing the BESS to reduce a company’s Scope 2 hourly carbon footprint would cost $657 per tonne of CO2 inventory reduction. While it would reduce carbon footprint on paper, it would cause an increase in CO2 in Earth’s atmosphere by an estimated 3,509 tonnes. The real-world impact of such an approach extends beyond GHG emissions. On coal-powered grids this increase in CO2 emissions would be coupled with an increase in co-pollutants(e.g., particulate) emissions, which are damaging to human health and cause premature death. This shows the high cost that would come with operating a BESS to reduce a company’s attributional carbon footprint on paper instead of aiming to reduce atmospheric CO2.

Download the white paper PDF: Measuring the Carbon Impact of Battery Energy Storage Systems

Hourly matching without additionality has little to no impact on emissions reductions

This post explains one set of findings from a larger research paper.

The full overview and paper are here: Impact Accounting and Hourly Matching: A Review

Hourly matching only accelerates renewable energy progress if additionality is part of the standard

The current proposal for an hourly matching standard in the Greenhouse Gas Protocol Scope 2 reporting standard does not include requirements that matched energy be additional. This means that voluntary corporate clean energy buyers could claim energy attribute certificates (EACs such as RECs or GOs) from already-built clean generation resources towards reducing their carbon footprint. This will likely lead to lower amounts of clean energy on the grid and higher emissions compared to a stricter standard.

Additionality is defined as an intervention that causes an action that would not have occurred otherwise. For example, a corporation signing a voluntary PPA for solar or wind energy (the intervention) provides the financial certainty for a new clean energy project to get financed, built, and interconnected to the power grid (the caused action). This has long been understood as a critical principle of clean energy procurement necessary to cause the desired reduction in carbon emissions (Bjørn et al. 2025).

Previous studies have reported that hourly matching can reduce emissions, but almost all of them assume at least some level of additionality for the procured renewable resources. Only one work (Ricks et al. 2023) considered hourly matching without an additionality requirement, in the context of US hydrogen production, and found that without additionality “a 100% hourly matching requirement loses all of its consequential impact." 

In order to understand the impacts of an hourly matching standard as it is currently proposed, we used the PyPSA-Eur capacity expansion and dispatch model to analyze the impacts of an hourly matching standard with and without additionality requirements in the European grid in 2030. We find that a non-additional hourly matching standard has little to no impact on total system emissions.

How our analysis modeled additionality and hourly matching

Because true additionality depends on a counterfactual, it can be difficult to determine outside of models. Instead, a “new build” requirement is often used as a benchmark for additionality in renewable energy. Many groups have also proposed that for a project to be additional, there needs to be a long-term contract, which has been shown to significantly reduce risk for renewable project financing.

Meanwhile, purchasing energy from an existing project that has already been built and is already in operation is — by definition — not additional, since the action (building the generation resource) happened before the intervention (purchasing the RECs).

We modeled additionality using scenarios where only new build resources are allowed to count towards the hourly matching goals, and modeled non-additionality using scenarios where clean generation of any age can count towards the hourly matching goals (consistent with current GHGP Scope 2 proposals).

From an economic perspective, consumer demand for hourly matched RECs could increase the supply of clean energy, if the demand is high enough. In practice, we see that supply of unbundled RECs often surpasses demand, leading to low REC prices that have little impact on causing additional new renewable resources to be built.

Hourly matching proponents argue that its time-matching requirement will make REC supply scarce during certain hours, driving up the cost of RECs in those hours and leading to more investment in clean resources that generate during those times. However, this effect only occurs if the demand for RECs in those hours substantially exceeds the supply.

If unbundled RECs from existing generators are allowed (as in the current Scope 2 proposal), our modeling indicated that in the case of the European grid in 2030, a demand for clean energy attributes from 25% of all commercial and industrial (C&I) load is insufficient to cause investments that lead to significant emissions reductions.

Modeled scenarios

We also investigated the impacts of different methods of accounting for clean attributes of energy consumed from the grid.

For all three of these scenarios, we modeled a requirement that procured resources are all new build (additional). We then modeled the scenario (“No New Build Req”) where there is no new build requirement by allowing consumers to count any amount of clean energy credits up to the total amount available on the grid.

An illustration of different ways of counting grid CFE for an hour with the same amount of purchased CFE. Assuming an hour where 50% of generation on the grid is carbon free and participating consumers have 75% of their load matched by a carbon-free PPA resource. If Grid CFE is counted proportional to “imports”, the 50% of CFE on the grid is applied to the 25% of load that is not met by the purchased CFE, increasing the hourly matching score by 12.5% to a total of 87.5%. If Grid CFE is counted using the SSS, the 50% of CFE on the grid is applied to the entire load, increasing the hourly matching score from 75% to 125%. If there is no new build requirement, consumers could meet up to 100% of their matching requirement with clean energy credits from grid resources if their demand is less than the total amount of clean energy credits on the grid in that hour.

No additionality means no impact

Without a new build requirement, we find that hourly matching has no emissions benefit for matching levels up to 90%. Even at a 100% hourly match, it has only a small benefit (4 MT) compared to the emissions caused by the load (62 MT). This is likely because there is a large amount of carbon-free energy already on the grid in Europe in 2030 without the addition of corporate procurement. If the corporate procurement is not limited to new build, buyers can take credit for the many carbon-free generation sources that already exist on the grid, including wind, solar, nuclear, and hydro. These purchases are non-additional, so they do not lead to changes in total system emissions. To achieve 100% matching, some additional resources are required, but they amount to a comparatively small amount of wind and battery storage resources. The battery storage resources are mostly dispatched to charge during times when there is excess CFE credits available and discharge during hours when there are fewer.

If a new build requirement was added, hourly matching is only impactful at high levels of hourly matching or if grid resources are not counted towards the hourly match. But these high-impact scenarios are also much higher in cost. Hourly matching that counts grid CFE either proportional to “imports” or SSS can have a significant impact on emissions if 100% hourly matching is achieved. However, below 100% matching, the emissions-reduction impact is small to non-existent. Again, this is likely caused by the high levels of CFE already on the European grid, which means corporate buyers can take credit for those existing resources and have a fairly high hourly matching score. The scenarios where no CFE from the grid is counted have a higher impact at all levels of matching, but also come at a much higher cost, exceeding €120 Billion in the 100% matching case. These high costs could be a deterrent, reducing the number of corporations willing to pursue voluntary renewable purchasing.

These results show that the specifics of how an hourly matching standard is written can lead to massive differences in reported emissions without any change in real-world grid decarbonization. The current proposed standard, which lacks a new build additionality requirement, will increase the difficulty of implementation by requiring more detailed accounting, but is likely to lead to little to no actual reduction in emissions. Adding a new build requirement to the standard could increase the impact, but it is highly dependent on how grid resources are counted towards the standard. The scenarios where impact is high come with a high cost however, which corporate buyers may not be willing to pay. This study also highlights the importance of considering all of the details when comparing a proposed standard to existing studies, as those studies may not apply to the proposed standard (as is the case here). This is the first time that hourly matching without a new build requirement (as proposed) has been studied, so previous research on hourly matching should not be used to project the impacts of the current proposed standard.

These results are part of a larger study we plan to release in the near future. If you are interested in learning more about it, or would like to access the code or data that was used to model these scenarios, please contact nat@watttime.org.

hero image: iStock / shaunl

More than one billion smart devices now using marginal emissions data to slash power grid pollution with WattTime's 'AER'

As Automated Emissions Reduction (AER) technology continues to scale in smart devices across the globe — including Toyota and BMW EVs, Amazon and Google Nest smart thermostats, Apple iPhones, and more — it has the potential to reduce three billion tonnes of carbon emissions per year by 2030.  

Oakland, Calif. — 14 October 2025 /PRNewswire-PRWeb/ — Environmental tech nonprofit WattTime today announced that more than one billion smart devices globally are now using its marginal emissions data to reduce greenhouse gas emissions from electricity use, in what WattTime calls Automated Emissions Reduction (AER) technology. For context, that’s about twice the combined global subscriber base of Netflix and Amazon Prime, and roughly half the number of Instagram users worldwide.

AER enables electric vehicles (EVs), thermostats, smartphones, and other internet-connected devices to automatically use electricity at times that will cause less pollution, which can vary significantly by location and time of day. This means avoiding the use of electricity when it requires a dirty, fossil fuel power plant to meet that need and instead using more power at times when excess renewable energy is available. 

“What matters to me is stopping climate change, not actually whether people do it with WattTime’s data or someone else’s,” said Gavin McCormick, WattTime Founder and Executive Director. “What’s important here is that so many people are now shifting electricity from times that genuinely make fossil fuel plants run, to times that don’t. I would be so thrilled if, next, someone else announces they’ve enabled even more AER users than we have.”

AER continues to be recognized for its positive climate impact and easy implementation, most recently earning a spot on TIME’s 2025 Best Inventions list last week. McCormick has similarly been awarded for his impact-focused efforts, including his work with AER. Last month, McCormick was featured on Forbes’ 2025 Sustainability Leaders List and named a winner of global philanthropy nonprofit Climate Breakthrough’s 2025 Climate Breakthrough Award.

As for success in the field, many of the world’s largest corporations have already adopted AER, in some cases adding it to more than 100 million new devices in one day. 

Some companies and products that have deployed WattTime’s AER thus far include:

For a detailed list of AER implementations, click here.

EV charging has been an especially impactful use case, due to its flexibility and high energy use. EV companies with AER-enabled charging deployed or in development make up 20% of the global EV market as of 2024. The ubiquity of AER for EVs continues to gain momentum, as WattTime’s partner Rivian is currently integrating WattTime’s marginal emissions data.

Other examples of the many flexible, internet-connected devices and services that can leverage AER include heat pumps, home appliances, battery-powered tools, building energy management software, data centers, virtual computing, and AI training jobs.

“AER is a force multiplier for building decarbonization. Together, our autonomous AI tech and AER demonstrated their positive impact on grid energy use. By shifting building electricity consumption to smarter times, we achieved two key outcomes: reduced emissions and greater use of renewable energy that would otherwise be wasted,” said Jean-Simon Venne, President and Founder at BrainBox AI.

AER’s growing reach has been bolstered by WattTime’s October 2024 global expansion of the first-ever real-time electricity marginal emissions dataset, which made AER available for nearly every country worldwide. After talking with its existing partners about their expansion plans, WattTime believes AER availability will likely double to reach two billion devices in about nine months. 

“Flexible loads like AI and electric vehicles are growing so fast. Based on the US Department of Energy’s projections of growth rates, if everyone adopted this simple, nearly free technology, AER could prevent three billion tonnes of carbon dioxide annually by 2030. That’s about 8% of all greenhouse gas emissions, or larger than any country’s emissions worldwide except China, the US, India, or Russia,” said McCormick.

For EVs in particular, AER can reduce grid emissions from charging by up to 18% annually, and more than 90% on individual days. In other technologies, use of AER has achieved reductions of 25–90%, depending on the device, time of day, and grid region. 

WattTime and others continue to develop new innovations in AER. Most recently, grid operators such as PJM, MISO, and NYISO have joined California in releasing official marginal emissions datasets that make it possible to measure the impact of AER using data straight from the local grid operator or government.

AER can also be programmed to reduce not only carbon dioxide emissions, but also health-damaging air pollutants. For example, companies like Toyota have integrated AER in their app software to create a charging schedule that is likely to reduce both the health and climate impacts of charging with grid electricity. AER can also optimize for the reduction of renewable energy waste, enabling power grids to absorb up to 20% more clean electricity from solar and wind farms.

The other key technology WattTime deploys using marginal emissions, Emissionality, also continues to scale rapidly, having grown from one billion watts to fifteen billion watts in the last twelve months. 

Learn more about AER here. And connect with the WattTime team by sending a message here.   

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About WattTime
WattTime is an environmental tech nonprofit that empowers all people, companies, policymakers, and countries to slash emissions and choose cleaner energy. Founded by UC Berkeley researchers, we develop data-driven tools and policies that increase environmental and social good. During the energy transition from a fossil-fueled past to a zero-carbon future, WattTime 'bends the curve' of emissions reductions to realize deeper, faster benefits for people and planet. Learn more at www.watttime.org. 

Media contact
Nikki Arnone, Inflection Point Agency for WattTime
nikki@inflectionpointagency.com

WattTime’s Gavin McCormick Wins 2025 Climate Breakthrough Award to Offer Free Impact Analysis for Carbon Accounting Standards

McCormick’s new initiative is one of five selected for its potential to achieve dramatic gigaton-scale “breakthrough” climate impact. 

Oakland, Calif. — 15 September 2025 — Environmental tech nonprofit WattTime today announced that its cofounder and executive director, Gavin McCormick, has been named a winner of global philanthropy nonprofit Climate Breakthrough’s 2025 Climate Breakthrough Award. Climate Breakthrough recognized McCormick for a new initiative that will offer free impact analysis to any interested government and private sector organizations developing carbon accounting systems.

Climate Breakthrough provides $4 million in multiyear, flexible funding — the largest climate award for individuals — for experienced environmental and social change leaders to develop, launch, and scale new high-impact initiatives that Climate Breakthrough concludes could significantly reduce global annual greenhouse gas emissions. All Climate Breakthrough awards must have the potential to materially change the lives of tens of millions and reduce at least 500 million tons of emissions within ten years of launch. 

Through this new initiative, McCormick and his team will help facilitate groups of independent scientists to provide free impact analysis of potential carbon accounting systems and policies before they are completed. The work will combine McCormick’s prior experience individually conducting such analyses at WattTime and the US Department of Energy, with his current experience in the Climate TRACE coalition facilitating groups of independent experts from many organizations in reaching consensus. 

Climate Breakthrough’s analysis concluded this initiative could exceed 2.9 gigatons of annual pollution reduction by 2036. Such large potential is driven by three trends: 

Many policymakers and standards bodies have expressed particular interest in impact analysis jointly conducted by groups of experts from multiple independent institutions. To that end, the new initiative will focus on metastudies, which review and analyze a set of existing studies to synthesize their findings, that examine varying results and explore where there is — and where there is not — consensus on which options would drive the most impact. 

Climate Breakthrough selected McCormick partly due to his technical expertise, but also his proven ability to gather diverse stakeholders and his exceptional talent for helping different technical communities understand one another.

For a full list of 2025 Awardees, read the Climate Breakthrough announcement here. And connect with the WattTime team by sending a message here.   

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About WattTime
WattTime is an environmental tech nonprofit that empowers all people, companies, policymakers, and countries to slash emissions and choose cleaner energy. Founded by UC Berkeley researchers, we develop data-driven tools and policies that increase environmental and social good. During the energy transition from a fossil-fueled past to a zero-carbon future, WattTime 'bends the curve' of emissions reductions to realize deeper, faster benefits for people and planet. Learn more at www.watttime.org. 

Media contact
Nikki Arnone, Inflection Point Agency for WattTime
nikki@inflectionpointagency.com  
Logan Varsano, Inflection Point Agency for WattTime
logan@inflectionpointagency.com