IRENA FlexTool

Countries exploring ways to ramp up solar and wind energy on their power grids should first conduct through flexibility assessments. The IRENA FlexTool performs power system flexibility assessments based on national capacity investment plans and forecasts.

FlexTool assessments reflect full power system dispatch and offer a detailed view of flexible generation options,  demand flexibility and energy storage, along with and sector-coupling technologies like power-to-heat, electric vehicles and hydrogen production through electrolysis.

The freely accessible, user-friendly FlexTool can analyse system operations using a time resolution aligned with real-world system challenges – an hour or less in the case of variable renewable energy (VRE) sources. It also provides least-cost optimisation of the generation mix along with flexibility solutions for grids, storage, demand-side response and sector coupling.

The FlexTool is data-driven and follows a relatively broad, general model structure. The user’s initial data largely determines what the model does. The  inputs required for a FlexTool simulation include demand, the generation mix, hydrological data, VRE time series, interconnections and fuel costs. Transmission data can be divided into separate nodes to reflect real-word power system characteristics.

Download IRENA FlexTool


The FlexTool was developed with the VTT Technical Research Centre of Finland Ltd., with the aim of assisting IRENA members in making a relatively quick yet thorough assessment of potential flexibility gaps as well as highlighting the most cost-effective mix of solutions to fill in such gaps. It is currently the only publicly and freely available (open-source) tool that performs both capacity expansion and dispatch with a focus on power system flexibility.


Learn more about the tool and how to use it through the new IRENA FlexTool training materials.

Read more about power system flexibility for the energy transition and on IRENA FlexTool methodology in the IRENA report. In addition, a few country case studies In addition, a few country case studies showcase the application of the IRENA FlexTool  jointly with IRENA Member Countries, including: