How can I show that a given open-source project does not exist yet?

I work in research (uni) and am writing a framework for heat processes to optimize their costs. This goes both for private houses and industrial processes. The goal is to enable industry players to see that/when renewable energies and heat reuse with heat pumps are cheaper than fossil fuels. I do this using digital twins for components and on a system level.

My boss hesitates because he thinks this must already exist. I want to pursue that path with my research, so any insights there are welcome, too, but this is primarily about the open-source project.

I searched GitHub and came up empty, but that is only a subset of the search. Do you have any idea how I can find this, one way or another? It would also be great if I could show that it likely does not exist.