WattTime API

The emission rate of the specific power plant that must ramp up or down to meet a change in electricity demand. Unlike average grid rates, the marginal rate provides a causal carbon impact calculation for dynamic workloads.

• Locational Marginal Emissions: Rates vary by grid node, not just region
• Operating Margin: Emission rate of plants currently operating
• Build Margin: Emission rate of new plants added to the grid
• WattTime uses a machine learning model trained on grid topology, fuel mix, and real-time power flow data to calculate this signal

The practice of time-shifting or location-shifting computational workloads to periods or regions where the carbon intensity of the electrical grid is lowest. This reduces operational emissions without reducing compute volume.

• Temporal shifting: Delaying batch jobs to low-carbon windows
• Spatial shifting: Routing inference to regions with cleaner energy
• Intensity thresholding: Pausing non-critical workloads above a set carbon intensity
• Requires a real-time signal like the WattTime API to make automated decisions

A procurement goal where every kilowatt-hour of electricity consumption is matched with carbon-free generation sources on an hourly basis. This moves beyond annual renewable energy certificate matching to granular, time-matched accounting.

• Requires hourly matching, not annual net-zero claims
• Google and Microsoft have committed to 24/7 CFE by 2030
• WattTime data enables verification of hourly consumption vs. clean generation
• Contrasts with Scope 2 market-based accounting which allows annual REC arbitrage

A methodology developed by the Green Software Foundation for calculating the rate of carbon emissions per functional unit of software. The SCI score enables granular, action-oriented comparisons of software system sustainability.

• Formula: SCI = ((E * I) + M) per R
  • E = Energy consumed by the software system
  • I = Location-based marginal carbon intensity (e.g., from WattTime)
  • M = Embodied emissions of hardware
  • R = Functional unit (e.g., per API call, per user)
• The I variable directly consumes marginal emissions rate data

An operational framework that extends FinOps principles to integrate real-time carbon metrics and sustainability objectives into cloud financial management and engineering workflows.

• FinOps + Carbon: Unifying cost and carbon optimization
• Chargeback models: Attributing carbon cost to teams and products
• Real-time dashboards: Displaying marginal emissions alongside spend
• WattTime API serves as the carbon intensity data source for GreenOps tooling, enabling engineers to see the carbon impact of deployment decisions

Indirect greenhouse gas emissions from the generation of purchased electricity, steam, heating, or cooling consumed by an organization. This is the dominant category for cloud-based AI workloads.

• Location-based method: Uses average grid emission factors
• Market-based method: Reflects contractual instruments like PPAs and RECs
• Marginal emissions data from WattTime provides a more accurate, consequential accounting than average grid factors
• Critical for GHG Protocol compliance and CSRD reporting