Member Story
How Microsoft, UBS, Avanade, NTT DATA, and partners built the Carbon Aware SDK — the first open-source toolkit for carbon-aware computing, now deployed on production banking systems and graduated from the Green Software Foundation.
Organisations involved
13–24%
Carbon reductions demonstrated at CarbonHack22
395
Participants at CarbonHack22 across 51 projects
40
Programming languages supported via client library
1st
GSF project to achieve Graduated status
The Problem
In 2021, organisations across the Green Software Foundation knew something frustrating: the electricity grid was cleaner at certain times and in certain places, but their software had no way to respond to that signal. Workloads ran on dirty power even when clean power was available hours later or in a neighbouring region.
Every organisation faced the same fragmented landscape. Carbon data came from different providers — WattTime, Electricity Maps — in different formats, with different access methods. Building a carbon-aware application meant each company reinventing the same integration work.
The need was clear: a shared, open-source toolkit that could centralise the logic, provide a common interface to multiple carbon data sources, and make it easy for any developer to build software that does more when the electricity is clean and less when it is dirty.
“Little awareness and slow adoption of greener software practices are the key obstacles that I see. It’s human nature to take the path of least resistance, especially when it’s hard to see and feel the immediate impact of your contributions.” — Kin Chiu, Executive Director and Sustainable Technology Lead, UBS
The Journey
2021
Members of the GSF Open Source Working Group identified carbon-aware computing as a quick win. Vaughan Knight at Microsoft launched the Carbon Aware SDK — starting with command-line tooling and a .NET library.
About the Carbon Aware SDK project →2021–2022
Early conversations revealed companies needed not just a library but a centralised web API. By mid-2022, the SDK had a hosted API and a client library available in 40 different programming languages.
Carbon Aware SDK on GitHub →Oct–Nov 2022
The GSF ran its first-ever hackathon, coinciding with COP27. 395 participants submitted 51 projects built on the SDK. First place, Lowcarb, achieved 13% carbon reductions in federated machine learning. Second place, Zeus, showed 24% reductions in deep neural network training. Prize money totalled USD 100,000.
Read about CarbonHack22 →January 2023
UBS and Microsoft integrated the Carbon Aware SDK into UBS's Advanced Compute Quantum Analytics risk platform, using WattTime data to time-shift workloads. The first enterprise-scale deployment of carbon-aware computing on a production banking system.
Read the UBS carbon-aware computing whitepaper →2023–2024
Vesta used the SDK to shift wind turbine simulations to cleaner windows. NTT DATA and NTT contributed the .NET 8 upgrade (v1.4), adding Prometheus and Grafana integration and Kubernetes-level carbon monitoring dashboards.
Read about the .NET 8 upgrade →April 2024
The Carbon Aware SDK became the first software project in the Green Software Foundation's history to achieve Graduated status, meeting all acceptance criteria including public release, clear documentation, and evidence of usefulness.
Read about the SDK graduation →October 2024
Energy Web delivered the world's first decentralised computation nomination system based on sustainability factors using the Carbon Aware SDK — extending carbon-aware computing into blockchain and Web3.
Meet Mani Hagh Sefat of Energy Web →Carbon aware software does more when energy is clean and less when it's dirty.
Green Software Foundation
Who came together
Vaughan Knight
Principal Engineering Manager
Microsoft
Launched and led the Carbon Aware SDK project from inception through graduation.
Kin Chiu
Executive Director and Sustainable Technology Lead
UBS
Drove UBS's strategic cloud initiative and led the Sustainable Technology Guild that connected UBS to the GSF.
Paul McEwen
Global Head of Technology Services
UBS
Championed the first enterprise-scale carbon-aware computing deployment on a production banking platform.
Chris Lloyd-Jones
Head of Open Technologies
Avanade
Contributed to SDK development and CarbonHack22 sponsorship.
Mani Hagh Sefat
CTO and Board Member
Energy Web
Delivered the world's first decentralised carbon-aware computation nomination system.
Elisabeth Brinton
Corporate Vice President, Sustainability
Microsoft
Executive sponsor connecting Microsoft's sustainability commitments to GSF collaboration.
Takuya Iwatsuka
Engineer
NTT DATA
Led the .NET 8 upgrade for Carbon Aware SDK v1.4.
Damien Roux
Engineer
NTT DATA
Contributed to the .NET 8 upgrade and ongoing Carbon Aware SDK maintenance.
Yasumasa Suenaga
Engineer
NTT DATA
Contributed to the .NET 8 upgrade engineering work.
In their words
"The way we design and build our applications has a direct relationship to how much carbon they emit. With a better understanding of the impact our application designs have on the environment, we can make choices which have a more positive impact on the planet. "
Paul McEwen
Global Head of Technology Services, UBS
"Little awareness and slow adoption of greener software practices are the key obstacles that I see. It's human nature to take the path of least resistance, especially when it's hard to see and feel the immediate impact of your contributions. "
Kin Chiu
Executive Director and Sustainable Technology Lead, UBS
"At Microsoft, we are committed to helping organizations reach their sustainability goals. Carbon-aware computing advances the measurement and reduction of carbon emissions associated with software technology at a global scale. "
Elisabeth Brinton
Corporate Vice President, Sustainability, Microsoft
We recognize and appreciate the contributions from Avanade, Microsoft, UBS and NTT DATA in helping us achieve this milestone.
The hackathon engaged the most talented developers from around the globe in building the best carbon aware application using the GSF Carbon Aware SDK.
The first enterprise-scale implementation of carbon-aware computing using the software carbon intensity (SCI) specification and carbon-aware-sdk is capable of avoiding multiple metric tons of CO2eq from entering the atmosphere -- every year.
We're revealing what took place behind the scenes and how NTT and NTT DATA are using the latest version of the Carbon Aware SDK.
Moving from theoretical sustainability to verifiable impact.
The Carbon Aware SDK was built by organisations who came together through the Green Software Foundation. Join us to collaborate on the standards, tools, and training that reduce software's environmental impact.
Already using the Carbon Aware SDK? Start with the quickstart guide at carbon-aware-sdk.greensoftware.foundation
