There’s a tweet I saw about this
It’s pretty simple to estimate. Google says first 8tb hard drive was released in late 2014. Google says first 16tb hard drives were released in 2019. That’s a doubling of disk space in 5 years, all on the same 5 watt power budget. So relying on proof-of-space means you get more efficient over time … it’s built in.
On top of that, if SSD tech eventually gets a lot cheaper, things will go way below 5 watts, since SSDs require dramatically less power.
Looking at their specs, the SSD has an average consumption of 2.7W while in active use, and only 0.05W when idle. The mechanical 3.5" drives, however, have an average consumption of 4.1W while in active use, and when idling, they still use 3W of power
I’m skeptical this can happen particularly quickly given the price of 4tb and 8tb SSDs right now… but a decade or more from now… seems possible!