Then he should know that if you have solar PV linked to export that when the mains is down due to a power cut it doesn't generate as it matches the phase of the network and without that signal it won't export or even power your house.
Actually if you have the PV system linked to grid which nearly all are, then any disruption to grid (voltage/frequency etc) supply will result in the PV inverter shutting down instantaneously as a safety requirement and it takes the inverter about 3 minutes to start up again once all the grid requirements are met. In the UK its classed as G98 (single phase) and G99 (3 phase) regulations.
Some of the many reason's that these huge warehouses don't get covered in Solar panels are:
1/ large roof installations are more costlier than a large ground mount to install.
2/ These warehouses normally have only a grid connection that cover the needs of the warehouse which won't be much compared to say a manufacturing facility - therefore you can only install a PV system that will not exceed the sites incoming fuse/cable capability.
3/ Legal nightmare as the occupiers of the warehouses are rarely the owners of - therefore legal consents for renting of roof space etc etc
4/ No requirement in planning to install Solar PV - idiotic but hey that's Government policy for you!
