I’m trying to understand the physics behind AC load distribution when distributed on-site generation is installed and the load is also connected to the grid.
In the diagram below, I have a building that has a PV Array installed and it is also connected the utility.
There a number of hypothetical scenarios that could occur:
1) “Building Load 1” draws 100 kW of power and the PV array is generating 100 kW of power therefore the grid utility is not being used to power the building load.
2) “Building Load 1” draws 150 kW of power and the PV array is generating 100 kW of power therefore the grid is providing the 50 kW
3) “Building Load 1” draws 50 kW of power and the PV array is generating 100 kW of power therefore 50 kW of power is being fed back into the utility.
Are those scenarios correct? If so can someone please explain how this works and also the physics behind this?
Given the “Building Meter” position it will monitor the utilisation of the grid and how much energy the PV array puts back into the grid if the building load is less than the solar generation, but how does this occur? How is the power distributed and how does the net value at “Building Meter” measure this? Lastly, how is this being regulated?
I’d be interested in a high-level explanation as well as a more advanced explanation to help me join the dots.
Thank you in advance.