Open Energy Transition (OET): Grantee Spotlight (Q3 2026)

The Giving Green Fund plans to award a restricted grant to Open Energy Transition (OET) to support its work in low- and middle-income countries (LMICs) across three areas: making open-source grid-planning and optimization tools ready for institutional use, expanding a global task force that closes priority functionality gaps in those tools, and building local modeling and training capacity. OET is a nonprofit software organization and think tank registered in Germany that develops and maintains open-source tools and data for energy-system planning, working through a globally distributed team.

OET's work falls within our philanthropic strategy of derisking clean electricity investments in LMICs. Please see Giving Green's strategy report for more information, including recommended sub-strategies, theory of change, funding need, and key uncertainties.

Last updated: October 2026

What Is Open Energy Transition?

OET is a nonprofit founded in 2023 that develops and maintains high-quality open-source energy-planning models and supports their adoption by energy institutions worldwide. Grid models are crucial for deciding where and when ministries, utilities, and grid operators build transmission and distribution, generation, and storage infrastructure, and can shape investments and emissions for decades to come. Many planning institutions worldwide currently rely on proprietary modeling software, which is often too expensive and hard for LMICs to adapt. Open-source models, however, remove software licensing costs and restrictions, allowing LMICs to conduct high-quality, tailored modeling and providing greater transparency than proprietary models.

OET develops and maintains open-source planning tools ready for adoption, supports institutional adoption, integrates user feedback to improve model effectiveness, and trains the planners and institutions that use them by working with universities and other local organizations to disseminate training regionally. Open-source models can benefit all countries, which is why OET works globally. The work supported by Giving Green, however, prioritizes building modeling capacity in Africa, Asia, and Latin America.

What Are We Funding, and How Could It Help Address Climate Change?

We are providing funding to support OET’s work in LMICs across three areas:

• Making open grid-planning tools institution-ready by improving usability, documentation, data integration, workflow automation, reliability, and secure deployment, and testing those capabilities with institutional users
• Expanding the Global Open Source Task Force, which maintains dedicated developer capacity to identify the functionality gaps that constrain professional adoption of open-source tools and contribute to fixing shared tools
• Building local modeling and training capacity, through reusable open courses and materials, applied workshops, train-the-trainer formats, and delivery partnerships with universities and local organizations across Africa, Asia, and Latin America

OET plans to use Giving Green’s funding to cover staff time supporting these three areas.

In our derisking clean electricity investments in LMICs strategy report, we identified implementing grid planning and reliability best practices and developing and aggregating knowledge to improve regional capacity as promising sub-strategies. Specifically, open-source models allow decision-makers to build and retain local modeling capacity, reduce dependence on proprietary software and external consultants, and support their ability to independently develop and integrate clean energy resources. We believe OET’s work aligns well with both sub-strategies and will help address climate change by enabling LMICs to plan better grid systems that attract more financing and integrate more clean energy resources.

Why Do We Think Open Energy Transition Will Use This Funding Well?

OET leads in open-source energy planning. It co-maintains PyPSA, which is one of the most widely used open-source modeling tools, and works directly with more than 20 grid operators, regulators, ministries, and civil-society organizations. OET estimates it has trained more than 200 practitioners so far. For example, in Zambia, OET built an open-source integrated resource planning tool with a utility and helped train staff to use it; in India, a renewable energy developer adopted OET-supported open-source methods to secure 24/7 clean energy power purchase agreements. Given its deep technical capacity and success working with the global energy community, we are confident that OET will use this funding effectively to drive real progress on clean energy and climate goals.

We publish grant spotlights to offer transparency to Giving Green Fund donors and resources for those interested in the impact strategies each grant supports. Giving Green believes our Top Climate Nonprofits have the greatest impact potential for large, unrestricted gifts. For several reasons, we also disburse and recommend grants to other organizations surfaced through our research process for work that we believe is at least as impactful as grants to our top recommendations. 

This is a non-partisan analysis (study or research) and is provided for educational purposes.

OET is a registered nonprofit in Germany.