Bitcoin exchange would help North Korean exchange their existing currency for Bitcoin, a currency accepted worldwide.
You don't need 24 hours electricity to store bitcoins in your wallet.
If north koreans knew how little freedom they had in comparison to the rest of the world, they probably would have rebelled and overthrew Kim Jong a long time ago.
North koreans don't own modern luxuries like cell phones or computers & if they did, they certainly aren't able to access the internet of the outside world in a way that would allow them to use bitcoin.
Its not that north koreans lack 24 hr electricity. Its more like their entire civilization exists in a pre electrical age. Only the military and elites have electricity. Everyone else is using smoke signals or whatever people used to communicate before electricity and telegraphs were invented.
I believe they know or imagine how the rest of the world is, because even being a reestricted country sometimes one or two foreigners appear there, with the government permission, so they can show some pictures of external world, maybe a modern cell phone, tablet...
Unfortunatelly they look a weak people, without unity, unable to organize a revolution inside their country, maybe they were brain washed since they were childs like terrorists do with their children.