# How to simulate reduced system inertia while integrating renewables?

From a given raw and dyr file, i have replaced some of the conventional generator models in there (such as GENROU) with renewable models, such as REGCA1. For example, for 25% renewable integration, the power output of the conventional units are reduced by 25% and a renewable unit is being added to fill in the gap in the raw file, with the corresponding model in the dyr file.

Now, to simulate reduced overall inertia of the system (which is a well-known impact of renewable integration), should i also reduce the MBASE of the conventional generator units and/or the intertia parameter in the corresponding GENROU model? Is this the correct way to do it?

Thanks in advance for your help.