Hourly matching of scope 2 emissions can further incentivise decarbonisation

Key points

• Electricity generation is responsible for a significant share of the global greenhouse gas emissions heating the planet. Decarbonising the power sector, particularly via industrial and corporate use, is crucial to meeting climate targets.
• Current standards for businesses to measure the emissions from their electricity use are based on annual statistics for energy generation by the grid and clean electricity purchases by companies. However, the renewable power that companies purchased may not have been available on the grid at the time they used the electricity. This mismatch means the annual approach doesn’t accurately reflect, and often overestimates, the amount of renewable electricity used by companies, creating a disincentive to build out more renewable energy.
• A proposed solution is to shift to hourly matching, where each hour of electricity used by a company must be accounted for by renewable electricity generated and attributable to its load in that same hour. This has been proposed and is currently under consultation as part of the Greenhouse Gas (GHG) Protocol’s guidance update. 
• Compared to annual matching, hourly matching can result in further emissions reductions and can further incentivise decarbonisation, but comes at higher costs. Targeting a lower range than 100% renewable electricity reduces associated costs while maintaining climate benefits.
• Hourly matching requires integration of energy storage systems and real-time data. While data and grid infrastructure gaps need to be addressed, the viability of hourly matching is growing. Currently, 45 projects are operational across five continents and hourly matching tariffs are available across 73% of global electricity demand. 
• To manage the transition towards hourly matching, academic experts and standard setters, such as the GHG Protocol, advocate a phased implementation strategy. 

Emissions accounting needs updating to reflect climate ambition

Nearly 40% of global greenhouse gas emissions are released through energy generation. Corporate and industrial users account for half of that power demand, making decarbonisation of the sector crucial to meeting global targets. Businesses plan their climate strategies based on their emissions, which are measured across three categories, scopes 1, 2 and 3. 

Broadly speaking, scope 1 emissions are generated by on-site processes. Scope 2 emissions are generated elsewhere through energy purchased to power a business’s operations. Scope 3 emissions comprise all other emissions produced across a business’s value chain, including those generated through the use of its products.

The Greenhouse Gas Protocol (GHG Protocol) sets out standards for companies to account for their emissions, enabling them to enact meaningful decarbonisation plans. The GHG Protocol is updating its Scope 2 Guidance to provide additional transparency and impetus for the uptake of renewables. The public consultation for this update ended in January 2026, with the release expected in 2027. This briefing sets out the rationale for the proposed changes and examines their feasibility.

Annual matching lacks the accuracy required to incentivise decarbonisation

Currently, most companies and industrial actors use annual matching to account for scope 2 emissions. There are two main ways to do this: by location, based on the average annual grid emissions where they consume electricity; or through market-based instruments such as certified renewable electricity or power purchase agreements (PPAs) to secure long-term contracts with renewable electricity providers.

What these two accounting methods – location and market-based – have in common is that they often mask a mismatch between the timing and location of reported emissions and the actual electricity that companies consume. Companies can reach 100% renewable targets by procuring as much renewable electricity as they consume within a year, while still using electricity from non-renewable sources if they operate at times when the grid’s power mix comes from fossil fuels. But annual matching means there is no incentive for companies to shift demand to periods when more renewable electricity is available.

When annual matching for scope 2 emissions was first introduced by the GHG Protocol’s guidance in 2015, purchasing renewable energy certificates helped to incentivise the deployment of renewables as they were more expensive than fossil fuel sources. The purchase of renewable certificates created demand when price alone would have been a disincentive. However, this model allowed companies to claim 100% renewable electricity use even when this was not the case.

Renewables are now cheaper than fossil fuel-powered electricity, so more transparent matching is needed to spur further shifts to decarbonised power. Several studies have found that annual matching results in limited or no emissions reductions, as the renewable electricity procured by companies would have been generated regardless of their 100% renewable targets and does little to displace fossil fuels. 

Hourly matching provides more accurate emissions accounting

In the update of its 2015 guidance, expected to be released in 2027, the GHG Protocol has suggested hourly matching as an alternative to overcome the shortfalls of annual matching. Hourly matching, also referred to as “24/7” or “granular” reporting of scope 2 emissions, means matching every hour of electricity consumption with local generation from renewable sources. 

This means there is no mismatch between the electricity consumed and the emissions reported. If a company wants to claim they use renewable electricity in any specific hour, it must show that an equivalent quantity of renewable electricity was generated and attributable to their load in that same hour. This method of accounting sends stronger market signals for renewable electricity, creating meaningful incentives for faster decarbonisation.

Modelling of hourly matching in different geographies shows that it can reduce emissions compared to annual matching. Targeting 100% renewable or carbon-free electricity comes with a significant cost premium, particularly when targets exceed 90%. A recent study found that partial hourly matching, with compliance in the range of 80-90%, can reduce costs while maintaining emission reduction benefits. In some contexts, hourly matching is predicted to result in fewer emissions at a lower overall cost to the system. Cost premiums are lower where renewable energy is more readily available and decrease as technology costs decrease (see Box 1 below). 

Overcoming feasibility constraints for hourly matching 

Data availability for hourly matching is increasing

Hourly matching of renewable electricity purchases and actual electricity delivered requires storage system integration, for example, by expanding battery capacity, as well as real-time data collection and monitoring systems on both electricity production and consumption sides. In some countries, significant data and grid infrastructure already exist to facilitate hourly matching. For example, in Europe, electricity trading occurs in 15-minute intervals, which more accurately reflects generation and demand, providing a more flexible system that can better adopt renewables. France uses monthly matching, and Switzerland plans to adopt quarterly matching before 2028.

In other countries, more upgrades will be required. For example, in Taiwan, an electricity system with a 15-minute interval matching mechanism and policy infrastructure lays a strong foundation for the introduction of hourly matching, but further advances are needed. 

Electricity companies are also moving towards more granular systems. Already, hourly matched tariffs, which provide consumers with information about their electricity consumption on an hourly basis, are available in areas that encompass 73% of global electricity demand. A 2025 survey of 75 energy suppliers found 52 reported they already offer an hourly matching tariff or plan to introduce one in the next six months. There was a fourfold increase in offers launched between 2024 and 2025, showing that adoption of hourly matching tariffs is accelerating. 

Further support from power utilities can also facilitate the introduction of hourly matching, as is happening in several US states. Peninsula Clean Energy, a power utility for local governments in California, is working to provide customers with 99% renewable power with hourly matching. Additionally, a number of data platforms and software tracking providers can help bridge data gaps and support hourly matching optimisation.

Shifting to hourly matching would also require initial technology and reporting updates from electricity consumers to meet regulations. However, the updated GHG Protocol proposal will not burden small businesses, as it states that hourly matching will not be a requirement for companies that fall below a specified electricity consumption threshold.

New projects demonstrate the feasibility of hourly matching in practice

Already, 45 projects across five continents utilise hourly matching in their operations. While these are predominantly small-scale, they demonstrate the feasibility of implementation across different contexts. In 2025, China and India established their first hourly matching projects.

Microsoft and Google have announced plans to purchase 100% carbon-free electricity and energy, respectively, with hourly matching by 2030, having signed multiple clean energy contracts with suppliers in different countries. For example, in Germany, Google has an ongoing contract with energy supplier ENGIE to provide Google’s German operations with near 85% carbon-free energy. However, Microsoft may be reconsidering its targets due to the expansion of data centres that use large amounts of electricity.

Introducing hourly matching in phases can allow time to bridge existing gaps

Many research papers and modelling studies suggest a phased approach to implementing hourly reporting. In the short term, quarterly or monthly matching could already help improve renewable electricity claims by reducing seasonal variability. This is in line with the GHG Protocol, which states that a phased implementation period over multiple years could allow time for data and grid infrastructure supporting hourly matching to continue developing in regions where it currently does not exist. 

This is also compatible with the implementation of other policies that either already require hourly matching or will require it in the coming years. Under the EU Carbon Border Adjustment Mechanism (CBAM), imported goods, including electricity imports, must use hourly matching to report actual embedded emissions and prove lower emissions, rather than using a default emissions value. CBAM entered into force from 1 January 2026, and provides administrative infrastructure for hourly matching.

Additionally, the EU introduced hourly matching as a requirement for the production of green hydrogen from 2030 onward. Similarly, in the US, hourly matching becomes mandatory from 2030 for hydrogen producers to qualify for the clean hydrogen tax credits.

Hourly matching is feasible under a phased approach with realistic targets 

While advances in digitalisation, grid infrastructure and data availability upgrades will be required, in many contexts, relevant data is already available. Projects based on hourly matching are increasingly being deployed in practice, and emerging policy can support initial regulatory frameworks. However, a phased approach with a realistic target below 100% renewable electricity matching will help to ensure technical and economic feasibility.

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  Many studies and targets relating to hourly matching refer to “carbon-free energy,” which also includes nuclear energy in addition to other renewable sources.