Hi guys, I ran the numbers today to create some OC:
As far as I can see BTC requires around 1,000kWh for a transaction. However, these numbers fluctuate a lot and generally trend up with more miners entering. An electric train uses around 2,000kWh for 100km, so I found the train a good enough analogy. The Lightning Network doesn’t play a role because BTC always needs PoW to finalise transactions.
Ethereum 1 (PoW) comes in at about 63 kWh. This number will change a lot with Eth2, however, we don’t have a date for that yet. Electric freight trucks use around 130 kWh / 100km. So I picked a small truck as comparison, I think it’s close enough to get the idea.
Lastly, ADA looks pretty good at only 0.5 kWh. Electric scooters tend to consume 1kWh per 100km so I picked this up-an-coming vehicle. Alternatively, the electric skateboard would have also worked as a slightly lighter vehicle.
After some feedback I changed BTC from a commuter train to a freight train.
More ideas appreciated 
I’m Frank and I run the Avocado Pool with my partner Nhi.