It missed us by 9 days

The scary thing is .. this could kill hundreds of millions if not billions. 

A shortage of medical supplies, reduced transport, no running water, no heating, no electricity, no communications and no transport of or refrigeration of food.

For at least a few years society would be a mess. You'd have cities at first go dark and after a few days riots and mass chaos due to shortages of resources. 

You'd also end up with oil shortages.

Even cars turned on could be fried. 

Cities could collapse into chaos. In towns and villages they'd be confused for weeks and have limited communication with big cities and then they'd end up seeing soooo many people fleeing cities to their rural less urban areas for food etc. 

Governments would try to prioritize generators for hospitals and civic buildings. 

Military would have to be deployed on streets to mantain order. A martial law for a long period. Curfews. Starvation, increased disease. 

By the time we have the entire world grid restored .. hundreds of millions or more will be dead. 

Also you can bet huge war between nations would break out over resources. Imagine china struggling and turning on Mongolia or Russia turning on the EU.

It would take years to rebuild the power grid and replace the lost technology but it could take 25 years for the economy and social order to fully return to normal. 

We need to have emergency protocols in place at places of government where if NASA or the ESA get a few minutes notice of a huge solar flare incoming that within a minute power stations as many as possible can be shut down. No power for a few hours but then they can be turned back on. If not shut down before we are hit they won't ever turn back on, they'll need rebuilding.

Its not even a question of if we get hit by a big one .. it's when. It could be in 2025 or 2050 or 2090 but it's coming and could be soon.