24/7 Carbon-Free Energy and Hourly Matching for Data Centers

Most corporate clean energy claims today rest on annual matching. A company totals its electricity use for the year, buys or produces the same number of megawatt-hours of renewable energy certificates, usually through power purchase agreements or unbundled purchases, and reports that its use was 100% renewable. The certificates can come from a solar farm’s June output while the consumption happened on a December night.

Hourly matching, often called 24/7 CFE, sets a stricter test. In each hour, the clean generation a buyer claims must come from a source that could plausibly have delivered power to its load in that hour. The GHG Protocol frames the change as reducing how often companies report clean electricity inputs they could not have consumed, and it acknowledges that an hourly-matched inventory will usually show higher emissions than an annual one unless clean attributes are procured for all hours.²

Data centers make the gap between the two methods wide. A large campus runs at a high load factor, drawing nearly the same power at 3 a.m. in January as at noon in July. Solar covers part of the day, wind varies by season, and the night and still-air hours are where annual claims and hourly reality diverge most.

The GHG Protocol Scope 2 Guidance sets the rules most companies use to report emissions from purchased electricity. The GHG Protocol opened public consultations in October 2025 on revisions to Scope 2 and on a separate electricity-sector consequential accounting method.¹

For the market-based method, the proposal would update Quality Criteria 4 from requiring contractual instruments to be matched “as close as possible” to consumption to requiring hourly matching for large organizations.² Key details in the proposal:

• Organizations under a size threshold would be exempt and could continue annual matching.²
• Where hourly instruments are unavailable, production and load profiles could be combined with monthly or annual certificates.²
• Hourly matching would apply only when companies make voluntary clean energy claims, not to residual-mix reporting.²
• A deliverability requirement would limit claims to certificates from places where the power could plausibly reach the reporting organization’s load.²

On July 29, 2026, the GHG Protocol published its summary of consultation feedback. It reported low levels of support for the hourly matching and deliverability proposals, with opposition most prevalent among companies and industry groups and in North and South America and East and Southeast Asia, while GHG reporting programs and data providers showed higher support.³ The summary is a record of feedback, not a decision; as of October 2026 the final standard and its effective dates remain open, so check the GHG Protocol’s current status before committing a procurement strategy to either outcome.³

The main evidence for hourly matching comes from Princeton University’s ZERO Lab. Its 2021 study, funded in part by Google, modeled voluntary procurement by 10% of commercial and industrial demand in California and PJM and found that hourly matching cut emissions more than 100% annual matching and drove more retirement of gas generation, at a higher cost.⁹¹⁰ The researchers also argued that 24/7 buyers create an early market for advanced firm clean technologies, helping drive their costs down over time.⁹

The opposing camp favors measuring impact rather than timing. In December 2022 Meta announced it had joined Akamai, Amazon, General Motors, Intel, Salesforce and others in the Emissions First approach, which aims to source energy by “emissionality,” the marginal carbon impact of each purchase, rather than by hour or grid.¹¹ Members wrote that they disagree with the Princeton conclusion that strategies other than hourly matching have “zero or near-zero long-run impact” on system emissions, and noted they had signed more than 35 GW of clean energy commitments.¹²

For a site search, the practical point is that the buyer’s camp shapes the brief. An emissions-first buyer may prefer projects on coal-heavy grids where new clean supply displaces the most carbon. A 24/7 buyer wants clean supply on the data center’s own grid in every hour.

The clearest U.S. regulatory use of hourly matching is outside data centers. Treasury’s final rules for the Section 45V clean hydrogen production credit, issued in January 2025, adopt three requirements that mirror the 24/7 debate: temporal matching, incrementality and deliverability.⁶

Under those rules, deliverability uses grid regions based on the Department of Energy’s National Transmission Needs Study, and whether a generator and a facility share a region depends on the balancing authority each is interconnected to, not geography.⁶ The rules do not apply to data centers, but they show how a regulator turns “same grid, same hour, new supply” into tests, and the GHG Protocol’s deliverability concept follows similar logic.²⁶

Hourly matching needs hourly proof. In the U.S., certificate tracking systems were built for monthly or annual RECs. S&P Global reported in September 2024 that PJM-GATS had become the first U.S. tracking system able to trade hourly certificates, with hourly trading available since August 2024.⁷ M-RETS has tracked hourly certificates since 2019 and supported the first hourly certificate transaction, with Google.⁸

Demand is growing. A LevelTen Energy survey reported by Utility Dive found that 71% of large buyers planned to buy or retire granular certificates in North America within three years, though some said they lacked enough information to decide.¹³ If the Scope 2 revision lands on hourly matching, sites served by registries with hourly tracking will be easier to document; elsewhere, buyers would rely on the proposal’s fallback of combining load profiles with less granular certificates.²

Under annual matching, procurement rarely changes the site. Under hourly matching, the grid at the site becomes part of the product. Google’s results show the spread: its 2025 report said 9 of the 20 grid regions with Google-owned data centers reached at least 80% CFE in 2024, while its overall average was 66%.⁴ For 2025, S&P Global’s review of Google’s 2026 report put the average at 65%, with Asia-Pacific grids (Singapore, Taiwan and Japan) at about 13%.⁵

Sites gain an advantage when the grid already carries firm clean supply, such as hydropower or nuclear, or when the utility will contract for new firm resources. Nevada’s Clean Transition Tariff, approved in May 2025 to bring 115 MW of Fervo enhanced geothermal to Google’s data centers through NV Energy, is the model many buyers cite.¹⁴ Storage, flexible load and on-site resources can close some gaps, but most hourly strategies depend on the grid.

1. 01Confirm whether the buyer reports on annual matching, hourly matching or an emissions-impact basis, and whether it plans for the revised Scope 2 rules.
2. 02Pull hourly grid mix data for the site’s balancing authority and model the clean share by hour.
3. 03Ask the utility about green tariffs, firm clean resource contracts and hourly data in billing; our guide to large-load tariffs covers the service terms.
4. 04Check which certificate registry serves the region and whether it handles hourly certificates.
5. 05Compare the cost of filling the hardest hours with storage, firm contracts or flexibility.

We include hourly procurement as a line item when a buyer’s goals call for it, next to capacity and timing. To compare candidate locations on that basis, get a site reviewed, and see our methodology for how we score power.