Flexibility assessment tool: IEA grid integration of variable renewables project

The IEA GIVAR project developed the Flexibility Assessment Tool (FAST) to broadly assess flexibility in different areas (which could be one power system or many power systems in the case of large countries). This tool determines the flexibility in an area, the operational, infrastructural and institutional factors limiting the usage of that flexibility, and the variability likely to be seen in the area. By combining these, the amount of additional variability and uncertainty (beyond load variability) that could be accommodated in the area can be determined in a semi-quantitative way, i.e. the MW flexible resource, together with a number of qualitatively described limiting constraints on that resource. This can then be used to make cost-effective recommendations on how to maximize the use of existing flexibility and increase the flexible resource in the area, as well as enable comparison among areas. A number of illustrative areas, representing different types of area which may be assessed, were examined to illustrate the usage of the tool.