So it is year 2024 and the max BTC supply is reached at ~21M.
Make it a century further away, more like 2140.
I'll speculate that the price of energy around the world will be higher than it is today, so that will cut into the miners profits.
Since it's a speculation we can go with this but do we also speculate what is happening to the price of miners?
Will it be economical to continue mining BTC going forward? The large mining operations can always set up a solar panel system to reduce energy costs.
Just putting up solar panels means nothing.
If the thing you do, be it mining, manufacturing or anything else is not profitable then it's stupid to build solar panels and use that energy for it. It would be far better to just sell the energy you make with the panels.
Even if some of the larger miners shut down, I'm sure there will be enough miners around the world where the blocks will still be completed, but it may take longer. (The mempool may grow like it did before X-mas last year) I'm not exactly sure how the lightning network will affect the mempool....?
This will last only till the next difficulty adjustment, then the difficulty will go down and blocks will just get mined at normal intervals.
I'm not exactly sure how the lightning network will affect the mempool....?
Is it possible that the S/W for BTC may be augmented to a semi POS type of system?
For the first one I must admit I have absolutely no clue as there is not just the LN to take into account but the percentage of users using LN, those using on-chain transaction and further more how many of those use segwit and how many they are in total.
If 100 000 users turn to LN but we have 500 000 that will still do normal transactions the mempool will go again to those levels and beyond.
As for the second, I said it before, the date is 2140, who cares what solution they will adopt at that time.