PG&E does not have the tools to monitor your solar system's performance. As your system produces energy, the electricity is first used by electrical appliances in your home. PG&E can only track and monitor excess electricity being sent back to PG&E's grid through net energy metering.
If you want to track your solar panel performance more closely, consider installing a professional monitoring system. Check with your solar contractor, as many provide this service.
The State of California maintains a list of authorized performance monitoring provider. To view the list, visit Go Solar California.