Properly Accounting for Scope 2 Emissions in the Age of Flexible Data Centers

Overview

The paper argues that annual-average location-based Scope 2 accounting misleads in two situations: when the grid decarbonizes, and when a data center can shift its load in time. An annual-average factor cannot tell whether load fell in a low-carbon hour or a high-carbon one. The author therefore proposes time-resolved accounting with hourly or sub-hourly emission factors.

In the example grid, the emission factor varies widely across hours: the lowest-decile hours are about 40% below the average and the highest-decile hours about 24% above it. That spread explains why shifting load toward cleaner hours changes real emissions while the annual average cannot see it. In the examples, annual-average and time-resolved estimates differ by up to about 15%.

The methodology section recommends 15-minute or hourly factors for flexible sites. Time-resolved accounting can reward load flexibility and can align carbon reduction with energy-cost reduction. The record shows percentages from one example grid, so the 15% and the 40%/24% figures should not be carried to other grids; they illustrate why the method is needed.

Key points

1. Annual-average and time-resolved Scope 2 estimates can differ by up to about 15% in the examples.
2. In the example grid, lowest-decile hours sit about 40% below the average emission factor.
3. Highest-decile hours sit about 24% above the average.
4. 15-minute or hourly emission factors are recommended for flexible sites.
5. Load shifting creates real emission changes that annual averages do not show.
6. Time-resolved accounting can reward flexibility and align carbon and energy-cost reduction.

Using it in design

• Allow an hourly (8760 h) emission-factor profile input in the carbon calculator, falling back to the annual average.
• When BESS or workload shifting is modelled, compute Scope 2 hour by hour.
• Show annual-average and time-resolved results side by side in the report.

Who should read it

Sustainability specialists doing carbon reporting and designers modelling flexible load and batteries.

Related standards

• GHG Protocol Scope 2 Guidance

Publication details

Authors

Stuart Sheehan

Publisher

Schneider Electric

Year

2025

Document number

WP 267

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation