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October 1, 2024
TransitionZero’s TZ-OSeMOSYS supports Climate Prosperity Plans for vulnerable nations
Summary
Climate-vulnerable countries, despite contributing little to global emissions, face severe climate impacts that strain resources, reverse development gains, and drive up the cost of essential services.
TransitionZero partnered with the Climate Vulnerable Forum and The Vulnerable Twenty (CVF-V20) to model electricity sector pathways to 2050 for seven countries using TZ-OSeMOSYS, our modernised, open-source version of the leading capacity expansion modelling package OSeMOSYS
By identifying cost-effective, climate-aligned energy transition pathways, this modelling provides a critical first step in the development of the V20’s Climate Prosperity Plans.
Results
7
countries modelled
Results
3
energy transition scenarios run per country
Problem
A significant number of countries across Africa, Asia, the Caribbean, Latin America, and the Pacific are among the most vulnerable to the accelerating impacts of climate change. Despite having contributed only a negligible share of historical and current greenhouse gas emissions, these nations are experiencing disproportionate harm — from rising sea levels and extreme weather events to long-term socio-economic disruption. Climate change is not only undermining development progress but also increasing the cost and complexity of delivering essential services and infrastructure. As a result, already limited national resources are being diverted from development priorities towards urgent adaptation efforts.
Climate Prosperity Plans (CPPs) contain ambitious economic and financial resilience strategies which are designed to attract investment and resources that advance the attainment of the Sustainable Development Goals (SDGs), 30×30 Global Biodiversity, and help keep the average global temperatures to the Paris Agreement’s 1.5°C safety threshold.
The Climate Prosperity Plans are our strategy to prosper in a climate-insecure world. The main hurdle that vulnerable developing countries face in climate action is finance. We lack the resources of our wealthy and major economic counterparts. Our fiscal space is under constant pressure from the impacts of climate change. And the negative effects of climate change are also worsening the already high cost of capital that we face to mobilize commercially viable investments. So the CPPs will also be our investment and financing strategies.
Nana Akufo-Addo
President of Ghana
Many climate-vulnerable countries lack access to the data, tools, and technical capacity needed to run complex energy system models — yet these insights are an essential first step for planning a just and effective energy transition. TransitionZero helps close this gap by providing accessible, high-quality modelling tailored to national contexts.
Product
TransitionZero partnered with the Climate Vulnerable Forum and The Vulnerable Twenty (CVF-V20), which represents 70 member countries highly vulnerable to a warming planet. The work generated supports the development of CPPs for seven countries: Haiti, Madagascar, Pakistan, Gabon, The Gambia, the Philippines, and Rwanda.
We produced modelling for electricity sector pathways to 2050 under three distinct scenarios, analysing the costs and benefits of different investment strategies to support long-term resilience and sustainability. This work was powered by TZ-OSeMOSYS — our open-source Python package for capacity expansion modelling. TZ-OSeMOSYS is a modernised adaptation of the original framework, rewritten to enhance usability, flexibility, and computational efficiency. It enables countries to engage directly with the modelling process, even with limited in-house capacity. This not only improves the quality of decision-making but helps build local ownership and lasting institutional knowledge. The full open-source package can be examined in detail here.
Looking ahead
TransitionZero’s modelling work provides an important evidence base that helps shape each country’s CCP. This helps make CCPS more grounded, actionable, and compelling to potential funders and international partners. partners and investors seeking to support climate-aligned development.
Soon, this kind of open and accessible modelling will be available to more users. Q2 2025 marks the release of our no-code platform for capacity expansion modelling and analysis, Scenario Builder. Designed for policymakers, analysts, and planners, and built on the same robust modelling foundations as the analysis conducted for CVF-V20 countries, Scenario Builder removes technical barriers and allows users to explore energy transition pathways through an intuitive, user-friendly interface. And all without writing a single line of code.
