5. Inputs and Evidence Sources

The methodology draws on the following categories of inputs.

5.1 Cloud Usage Data

To produce a metric for a unit of cloud usage, the methodology requires the usage attributes that identify it, being the cloud provider, the service or SKU, the region, the usage period, and the quantity or duration of use. These attributes are read from the client's cloud usage data, most commonly a cloud usage report. No cost or spend information is required.

5.2 Hardware Power Consumption Data

Server power consumption constants are aligned with methodologies used by authoritative bodies such as the US Environmental Protection Agency, the EU Ecodesign Regulation, and ISO/IEC 21836:2020, including benchmarks from the Standard Performance Evaluation Corporation. Power consumption data for memory components is sourced from manufacturers including SK Hynix, Kingston Technology, and Crucial. Storage power data is derived from the Berkeley National Laboratory's Data Center Energy Usage Report and Backblaze's annual drive statistics. Networking power data is derived from Intel network interface card specifications and a 2023 study on the electricity intensity of fibre optic cables by Thunder Said Energy.

5.3 Cloud Provider Published Data

Power Usage Effectiveness values are sourced from each cloud provider's own published sustainability and efficiency data, being the AWS Cloud Sustainability portal, Google Cloud's data centre efficiency reports, and Microsoft Azure's documented measurements of data centre water and energy use.

5.4 Grid Carbon Intensity Data

Greenpixie uses an internal tool called GPX Grid to produce hourly, region-specific Grid Carbon Intensity factors. GPX Grid sources data from a tiered hierarchy of national grid operator APIs, modelled national datasets, and international averages from sources such as the IPCC and IEA to account for upstream and lifecycle emission factors of the technologies and fuel types. Methodology and data selection are validated in collaboration with academic partners including Professor Alex Rogers at the University of Oxford.

5.5 Embodied Emissions Data

Component-level embodied emissions data is derived from the Boavizta project, lifecycle assessment studies by Gröger, J. et al. at the German Federal Environment Agency, the ADEME Base Carbone database, and the Morand, C. et al. MLCA study for GPU lifecycle assessment. Die-size data is sourced from the TechPowerUp CPU database and manufacturer specification sheets.

5.6 Water Consumption Data

Cloud provider Water Usage Effectiveness values are sourced from published sustainability reports by Google Cloud, Microsoft Azure, and AWS. Regional water intensity factors for electricity production are sourced from the World Resources Institute.

5.7 Cloud Infrastructure Research

Mapping each cloud SKU accurately to the hardware that delivers it requires a thorough understanding of the physical infrastructure that powers each service. Greenpixie conducts ongoing research into cloud provider infrastructure across multiple source categories, with findings reviewed and verified before they inform the hardware mapping.

Official service documentation and pricing pages are the primary source. These documents contain hardware specifications, resource allocation rules, capacity limits, scaling behaviours, and pricing structures that indicate the relationship between billing units and physical hardware. For each supported service, Greenpixie's methodology team reviews the relevant documentation in detail to identify which hardware components are involved in delivering each unit of work.

Pricing structures themselves carry significant hardware signals. The choice of billing unit, whether vCPU-hours, GB-seconds, requests, or GB-months, implies which hardware resources are consumed per unit of work. Pricing differentials between service variants, provisioned versus on-demand tiers, and regional price variations further inform the hardware profile.

Beyond official documentation, research draws on public technical disclosures made by cloud providers through conference presentations, published talks, engineering blog posts, and video content. Cloud architects and infrastructure engineers frequently discuss system design, hardware choices, and scaling architectures in public forums. These disclosures provide additional evidence for how services are built and what hardware underpins them.

All findings are assessed for their connection to specific hardware types before being used. Marketing language, tutorials, and promotional content are excluded. Only information with a defensible connection to identifying the hardware behind a service is retained.

5.8 Regulatory and Standards Sources

The methodology references the GHG Protocol Corporate Standard, the GHG Protocol Scope 2 Guidance, the GHG Protocol Scope 3 Standard, the GHG Protocol Product Life Cycle Accounting and Reporting Standard, ISO 14064-1, and ISO 14064-3. Regulatory context is drawn from the EU Corporate Sustainability Reporting Directive, the UK Streamlined Energy and Carbon Reporting framework, and the US Securities and Exchange Commission climate disclosure guidance.