What's LIPA? Long Island Power Authority? I don't think it would be legal or smart to tap the line side of the switchgear and route unprotected 13.8 kV cables to the solar panel installation. Thsoe calbes would be service entrance cables.
The cables should be protected by a fused switch or circuit breaker in the pad mount switchgear.
Where is the transformer located that steps up the solar power inverter output to 13.8 kV? On the roof?