[lawlessone]

>the new hash rate

would be 0

[lowracle]

Given that a 1 square meter solar panel produces 200W, and the energy efficiency of an Ebit E10 ASIC miner is 11100 * 10^6 hash per J, you can compute 200 * 11100 * 10^6 hash per second so no, in an apocalyptic event, the hash rate will hardly be 0.