Most rooftop solar systems are tied in to the grid. No grid = no power. Having it independant or switchable from grid tied to independant, means a lot more cash to be invested in the solar systems.

I research the effects of a large scale power failure for a large exercise and found that in my country:
- Regular consumers; fend for yourself.
- Fire and rescue, will get you out of the elevator.
- Sensitive organisations/buildings (hospitals, other care facilities, the water company) are equipped with emergency power generators.
- Emergency planning is for failure of backup power generation at sensitive organisations/buildings.
- Water pressure will remain on for a long time, since the water company have a independant emergency power generator and fuel. However delivered at 2 bar on ground level, so bad luck if you life up high.
- Our grid is redundant at the 150KV level. lower voltage lines are not redundant, but due to they way they are tied to each other, they can switch power from other connections from the 150KV grid and effectively reduce the size of the power outage.
- There are build in safetys in the grid to absorb power spikes.
- We have black start facility's used to restart regular power stations (pretty impressive gasturbine generator)

Fun part: crisis command centre was just equipped with new computers and big flat screens. Guys pressing al the power buttons at the start of exercise, power goes down... "Is this part of the training?", uhmm... No... Fuses blew. Electrician made a mistake with the new stuff. Atleast we found it during an exercise...