The Add Rooftop PV measure adds ElectricLoadCenterDistribuition object using an OpenStudio measure; in case you want some guidance on adding it using a measure.

@David Goldwasser, but in the description it says that it "will create new shading surface geometry above the roof for each thermal zone in your model where the surface azmith falls within the user specified range. Arguments are exposed for panel efficiency, inverter efficiency, and the fraction of each roof surface that has PV" but what if I just need ElectricLoadCenterDistribuition measure for implementing a CHP unit in a building (not PV)

@Raghda Derbel, You are correct, you would have to modify a copy of that measure, or make a clean new measure , which you can do in the OpenStudio Application, or PAT; and then copy the code related to ElectricLoadCenterDistribuition into your model. In addition to adding it to the model, you also need to asociate it with model objects that you want to use it

Ok thanks, I will try to modify the measure then! But what do you mean by "you also need to asociate it with model objects that you want to use it" ? (sorry but I am not familiar with this)