Time-based Energy Attribute Certificates (T-EACs), also known as Granular Certificates (GCs), are market instruments that certify the environmental attributes of clean electricity generation on an hourly basis, and can be used to verify the hourly matching of electricity consumption with clean energy generation. By linking energy use to actual clean generation in the same hour, T-EACs provide a more accurate and credible representation of when electricity use is truly carbon free.

Unlike conventional energy attribute certificates, which do not reflect the precise time of clean energy generation, T-EACs make system conditions visible on an hour-by-hour basis. This transparency strengthens compliance with emerging 24/7 carbon-free energy (CFE) standards, improves the integrity of decarbonization claims, and supports regulators and markets in assessing real progress toward clean-energy targets.

By exposing gaps between clean supply and demand, T-EACs create incentives for load shifting, flexible consumption, and targeted clean-energy investment during under-supplied hours. As a result, they help align procurement, system operation, and investment signals with real grid conditions - supporting system-wide decarbonization while strengthening transparency and accountability across energy markets.

Main outcomes of the solution 

• Sustainability: Improves the environmental integrity of decarbonization by aligning electricity consumption with actual clean energy generation on an hourly basis, supporting credible progress toward 24/7 carbon-free energy targets. 
• Business Value: Enables organizations to optimize clean-energy procurement and operations by identifying hours and locations with cleaner electricity, supporting carbon-aware strategies and reducing misalignment between sustainability commitments and operational reality. 
• Institutional Efficiency & Transparency: Provides time-resolved visibility into when and where electricity is clean, strengthening reporting quality, improving accountability and enabling regulators and market actors to assess system impacts beyond annual averages. 

Key deployment and scaling factors 

1. High-quality hourly metering and data pipelines that reliably capture electricity generation and consumption at an hourly resolution across assets, sites and regions. 
2. Harmonized certificate definitions and verification standards to ensure that time-based certificates are comparable, auditable, and trusted across markets and jurisdictions. 
3. Integration with digital forecasting and energy-management tools so users can act on hourly signals by shifting load, adjusting procurement, or optimizing operations in advance.
4. Formal recognition of time-based certificates in regulatory and reporting frameworks, enabling their use in compliance schemes, corporate disclosures, and hourly matching.
5. Sustained demand from large electricity consumers (e.g. data centres and industrial users) to create market liquidity, support, price discovery and incentivize new clean generation during under-supplied hours. 

Case Study 

Google, Flexidao and Electricity Maps (2021), Global

Since 2021, Google has piloted and progressively scaled time-based Energy Attribute Certificates (T-EACs) to track and match clean electricity consumption on an hourly basis across its data-center operations. In collaboration with Flexidao and Electricity Maps, the approach links Google's electricity use to the actual timing and location of clean power generation, moving beyond annual certificate matching toward more granular, time-aligned accounting.

Google works globally with Flexidao to automate the delivery of hourly data from clean energy projects under contract across the world, and match that data to EACs provided by registries, turning EACs into T-EACs. They then match the T-EACs to their hourly electricity demand and use hourly grid data from Electricity Maps to calculate their hourly matching percentage. In 2025, Flexidao converted a portfolio of Google's energy certificates into hourly format for over 100 sites, representing 10.5 TWh of energy across 7 countries.

Since the first pilot in 2021, registries across the world are quickly upgrading their systems to both issue and enable trading of T-EACs. The Registry Acceleration Fund, led by LevelTen and supported by the Granular Certificate Trading Alliance, recently announced funding for registries that "collectively issue or track more than 4,000 TWh of certificates across over 70 countries for more than 40,000 account holders." These infrastructure investments will lay the groundwork for T-EAC issuance and trading at a global scale.

In recent years, government regulatory frameworks and accounting standards have increasingly recognized the significance of hourly electricity accounting for effective clean energy policy design. Examples include clean hydrogen regulations in Europe and the US, clean electricity accounting within Europe's Carbon Border Adjustment Mechanism (CBAM), and proposed updates to the Greenhouse Gas Protocol Scope 2 Guidance to require hourly emissions accounting. T-EACs are an essential tool for enabling credible hourly clean energy claims within these and other emerging policy frameworks. [1,2,3]

References:

1. Accelerating a carbon-free future with hourly energy tracking I Google Cloud (November 2023) 
2. The role of Granular Certificates in improving clean energy credibility and impact I Google (December 2025)
3. Hourly Energy Accounting at Scale I Flexidao (September 2025)