I have also attached the PV facilitation letter

[Joj]

Dear Mrs. X,
Please find attached a manual to guide you through the portal, a quick guide to the monitoring system, the inverter’s user manual, a quick guide to your photovoltaic equipment.
I have also attached the PV facilitation letter approved from the Ministry of Energy & Water.

 

[Tarheel]

I would say a brief guide rather than a quick guide.

Say:

and a brief guide to to your photovoltaic equipment.