I don’t think you can feasibly use the Hawking radiation of large black holes as an energy source in our universe (even if you are patient).
My understanding is that larger black holes decay over ~10100 years. I did a botec a while ago and found that you maybe get 1 flop every 1030 years or so on average if we assume perfect efficiency and very few bit erasures in our reversible computing approach (I think I assumed about 1 bit erasure per 1010 or something?). I don’t think you can maintain a mega structure around a large black hole capable of harvesting this energy which also can survive this little energy. (I think quantum phenomena will decay your structure way too quickly.)
In that case, don’t dump waste heat into black holes so large that it’s impossible to use them as eventual energy sources. Instead dump waste heat into medium sized black holes, which can feasibly be used as eventual energy sources.
I think the size might have to be pretty precise to get this right (I think decay duration is cubic in mass), so they’d probably need to be engineered to have a particular size. (E.g. add mass to a small black hole until it hits the right size.)
But, yeah, with this constraint, I think it can maybe work. (I don’t know the decay duration for the smallest naturally occurring black holes. But as long as this is sufficient low, the proposal works.)
I don’t think you can feasibly use the Hawking radiation of large black holes as an energy source in our universe (even if you are patient).
My understanding is that larger black holes decay over ~10100 years. I did a botec a while ago and found that you maybe get 1 flop every 1030 years or so on average if we assume perfect efficiency and very few bit erasures in our reversible computing approach (I think I assumed about 1 bit erasure per 1010 or something?). I don’t think you can maintain a mega structure around a large black hole capable of harvesting this energy which also can survive this little energy. (I think quantum phenomena will decay your structure way too quickly.)
In that case, don’t dump waste heat into black holes so large that it’s impossible to use them as eventual energy sources. Instead dump waste heat into medium sized black holes, which can feasibly be used as eventual energy sources.
I think the size might have to be pretty precise to get this right (I think decay duration is cubic in mass), so they’d probably need to be engineered to have a particular size. (E.g. add mass to a small black hole until it hits the right size.)
But, yeah, with this constraint, I think it can maybe work. (I don’t know the decay duration for the smallest naturally occurring black holes. But as long as this is sufficient low, the proposal works.)