“100% clean energy” may describe annual matching—not every hour.
A contract or certificate can balance annual volumes without describing the electricity physically serving a facility at a given moment.
Primary sources ↓ · Limitations ↓
- Bright publication
- Source review
- Reading question
- When and where does the clean generation match the load?
Four words change the claim
Ask whether matching is annual or hourly, and global or regional. Annual global procurement can support clean generation while the facility still draws from a local grid with fossil generation in some hours. Hourly regional matching is a tighter claim, but it still needs metered load, generation and accounting rules.
Sources: DOE report on AI and energy · DOE Grid Talk: annual and 24/7 matching
Procurement is not physical isolation
A power-purchase agreement or energy attribute certificate is a financial and accounting instrument. It should not be described as a dedicated physical supply unless the interconnection and metering establish that relationship. The useful comparison is not “clean or dirty” but which temporal and geographic claim the evidence supports.
What this guide does not establish
- Carbon accounting methods differ.
- Hourly matching does not by itself resolve transmission constraints or marginal emissions.
- Bright did not calculate emissions for any facility.
Primary sources
DOE report on AI and energy ↗
Energy-system opportunities and constraints.
DOE Grid Talk: annual and 24/7 matching ↗
Discussion of the distinction between annual procurement and continuous matching.
Source-reviewed 2026-09-19. Source review means Bright compared this explanation with the linked records; it is not independent replication or expert peer review by Bright.