Interesting idea (very out of scope):

CPUs go into motherboards which use power supplies and RAM and a storage device to boot and run operating systems/code

This all adds up once plugged in to "at the wall" power pull (basically measured in watts per hour * 24 hours = how many kilowatts a day)

Then, you take how efficient the hardware is at say, a proof-of-work mining algorithm (hashrate)

Then you can sort by which CPUs are most efficient

I've yet to find a database that does this (probably for good reason, mining is pretty dumb)