Here is a small example on how-to create KML document:
I think you are using another version of Spatial Data Integrator and deduces then you are in the development team. As you seem to be one of the CtoC developers, I can ask you this question:
is the development of a KML Output component planned?
What will the next components of the future version of SDI?
Introduction to Talend Open Studio for Data Integration.
Practical steps to developing your data integration strategy.
Create systems and workflow to manage clean data ingestion and data transformation.