The SGI’s Energy Systems Modelling team deploy a variety of simulation platforms in our work - both for our own modelling and capacity-building workshops. Each of these tools offers a different set of features and strengths, so we choose the most appropriate depending on each project task and application.


IRENA FlexTool

IRENA’s FlexTool assessments reflect full power system dispatch and offer a detailed view of options for flexible generation, demand-side flexibility and energy storage, alongside sector-coupling technologies such as power-to-heat, electric vehicles and hydrogen production through electrolysis. FlexTool can analyse system operations using a time resolution aligned with real-world system challenges – a resolution of an hour or less in the case of variable renewable energy sources. It also provides least-cost optimisation of the generation mix combined with flexibility solutions for the grid, storage, demand-side response and sector coupling.

Visit the FlexTool site


HEGIT (Heat, Electricity and Gas Infrastructure and Technology) 

HEGIT is an optimisation model for coordinated long-term planning and short-term operation of integrated electricity and gas grids. HEGIT is designed for policy impact assessment and investigating the impact of different long-term strategies on the infrastructure requirements in the electricity and gas grids.

In addition, HEGIT incorporates heating service demand and the operation and planning of individual heating technologies in buildings. This feature allows the model to assess the impacts of different policies related to decarbonizing heating in buildings and fuel-switching schemes on the operation and long-term investment planning of electricity and gas networks.

The HEGIT model has been developed in-house at the Sustainable Gas Institute by Dr Pooya Hoseinpoori from our Energy Systems Modelling team. Read the full paper explaining the science behind HEGIT.  



OSeMOSYS is an open-source modelling system for long-run integrated assessment and energy planning. It has been employed to develop energy systems models from the scale of the globe, continents, countries, regions and villages. It can focuses on detailed power representations, or multi-resource (material, financial, all energy) systems. It is part of the Global OpTIMUS (Open Tools, Integrated Modelling and Upskilling for Sustainable Development) community of practice. 

Visit the OSeMOSYS website or Read more about the



Also part of the Optimus community, Climate, Land (Food), Energy and Water systems approach (CLEWs) focuses on assessing interlinkages between resource systems in order to understand how these are related with each other, where pressure points exist, and how to minimize trade-offs while potentiating synergies. This type of integrated assessments usually involve a strong quantification process which can be performed in different scales of complexity, either by 1) the use of accounting frameworks; 2) via the development of sectoral models (for water, energy and land use), and subsequent soft-linking of tools in an iterative process; or 3) making using of one single modelling tool that accounts for the representation of several cross- and inter-systems’ interactions. The models are then used to investigate questions related to the relevant nexus interactions.

Find out more on the CLEWS webpages.



UK TIMES is an energy system model of the UK that has been developed by UCL and the UK Department of Business, Energy and Industrial Strategy.  It is based on the TIMES model generator, similar to TIAM-UCL and ETM-UCL.  It was used to inform the UK Government's Clean Growth Strategy in 2017.

  • UK TIMES is the successor to the UK MARKALmodel.  During development, the entire design of UK MARKAL was reviewed and revised.  UKTM offers a number of new features:
    Sectors are realigned according to research and policy questions.  To enable different scenario baselines to be examined, taxes, policies and hurdle rates are added to the base model using separate modules.
  • The model baseline is calibrated to DUKESand NAEIdata for 2010.
  • UK TIMES includes emissions of all of the major greenhouse gases from energy and non-energy uses for the first time.  New technologies are available to reduce emissions from outside of the energy system.

The results from MARKAL and TIMES models are absolutely reliant on the generation of internally consistent scenarios.  In reality, consistency is seldom achieved as different high-level drivers are used to derive different demands.  UK TIMES provides an easier way to compare input assumptions and resulting outputs.

Find out more on the UK TIMES webpages



MUSE is our very own next-generation energy systems modelling tool – designed and engineered in-house by researchers at Imperial College London.

Visit our MUSE mini-site to find out the strengths our new platform brings