OSeMOSYS - the Open Source Energy Modelling System
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OSeMOSYS is a full-fledged systems optimization model for long-run energy planning. Unlike long established energy systems models, such as MARKAL/TIMES (ETSAP, 2010), MESSAGE (IAEA, 2010), PRIMES (NTUA, 2010), EFOM (Van der Voort, 1982) and POLES (Enerdata, 2010), OSeMOSYS potentially requires a less significant learning curve and time commitment to build and operate. Additionally, by not using proprietary software or commercial programming languages and solvers, OSeMOSYS requires no upfront financial investment. These two advantages extend the availability of energy modeling to large communities of students, business analysts, government specialists, and developing countries energy researchers.


OSeMOSYS is designed to fill a gap in the analytical toolbox available to the energy research community and energy planners in developing countries. At present there exists a useful, but limited set of accessible energy system models. These tools often require significant investment in terms of human resources, training and software purchases in order to apply or further develop them. In addition, their structure is often such that integration with other tools, when possible, can be difficult.

Energy specialists

The OSeMOSYS code is relatively straightforward and transparent and allows for simple refinements and the ability to conduct sophisticated analyses. As models are made to generate insights, OSeMOSYS allows a test-bed for new energy model developments.


Enabling graduate students to build and iteratively develop formal energy models will impart this knowledge base to very wide range of energy market roles and positions. Extending the human capacity of private and public policy makers to use and understand energy models is a key step in the effective use and interpretation of formal analytical tools. And growing human capacity in energy modeling in developing countries – whose institutions have relatively fewer research resources – is particularly important, given the growth of developing countries in energy related emissions, resource use, and demand for energy services.


OSeMOSYS community welcomes professionals and experts from different levels: decision makers, policy officers, energy planners, developers of new model functionalities, programmers.