The scope 2 revision: hourly matching

Why is scope 2 being revised?

Under the 2015 guidance, a company reports scope 2 twice: location-based, using grid averages, and market-based, using the emission rates of electricity it has contracted for or certificates it holds. Certificates are matched to consumption over a year and within broad markets, such as all of the United States or Europe. Critics argue that this lets companies claim zero emissions while relying on fossil power at times and places where no clean electricity is produced, and that cheap certificates rarely lead to new renewable generation. See location-based and market-based scope 2.

What did the scope 2 revision propose?

• Hourly matching: market-based instruments would count only against consumption in the same hour, with standard load profiles allowed where hourly meter data is missing.
• Deliverability: instruments would have to come from generation that could physically deliver to the grid where the company consumes the electricity.
• Feasibility measures: exemption thresholds so that most organisations would not need hourly matching, a legacy clause for existing long-term contracts, and a phased start.
• Location-based method: a hierarchy requiring the most precise accessible grid factors.
• Consequential impacts: a separate consultation on reporting the effect of clean energy purchases on the wider grid, outside the inventory.

Scope 2 revision: an office campus under hourly matching

A company's campus uses 10,000 MWh a year. It has a solar power purchase agreement that delivers 10,000 MWh of certificates a year, so under the current guidance its market-based scope 2 is zero. Its hourly meter data show that the solar output covers only 6,000 MWh of its consumption hour by hour, because the campus also uses power at night, in winter and on cloudy days, while the surplus midday output goes to the grid.

Under hourly matching, the 4,000 MWh not matched would be counted at the residual mix factor of 0.45 t per MWh, giving 1,800 tonnes instead of zero, even though location-based emissions of the campus are unchanged. To get back towards zero, the company would need storage, wind generation that runs at night, or contracts that supply power around the clock. If the company were small enough to fall under an exemption, or its contract were protected by the legacy clause, annual matching could continue.

What did the consultation show?

The consultation ran from 20 October 2025 to 31 January 2026 and drew nearly 1,100 responses from 56 countries. Support for hourly matching and deliverability was low among companies and industry groups, while reporting programmes, data providers and many NGOs were more supportive. The exemptions and the legacy clause had broad support, but many respondents doubted they were enough, citing cost, audit burden and data availability. Views on the location-based hierarchy were mixed.

What happened in 2026?

In July 2026, the Independent Standards Board asked the technical working group to develop further market-based reporting approaches, rather than finalise the original proposal, and any new proposal will go through the standard development process, which can include more consultation. Also in July 2026, the GHG Protocol and ISO agreed to combine their corporate standards, including scope 2, into a single standard, with a public consultation planned for the second quarter of 2027 and publication in the fourth quarter of 2028. CARB has said its SB 253 rules will use the 2015 guidance until it acts on any update. See the GHG Protocol explained and SB 253 from 2027.

What should companies do now?

Keep reporting under the 2015 guidance, with both methods. Collect hourly consumption data where meters allow, check how much of current certificate and contract volumes would match hour by hour, and consider the time profile and location of new power purchase agreements before signing long-term contracts. Explain any market-based target and the instruments behind it, since targets set on annual matching may need restating if the rules change. Certificates and contracts also have accounting consequences. See renewable energy certificates and power purchase agreements.

This guide is general information. It is not tax or legal advice for your situation.