Hello @nosuic
Those two articles are not talking about the same thing. The first is referring to whole network and second is referring to a single node.
Also, 600kWh = 0.0006 GWh since 1 GWH = 1,000,000 kWh
Giga is 1 billion Watts while Kilo is 1000 Watts.
To have data that can stand scrutiny you probably have to use by node data since that is what is mostly used when measuring Bitcoin. Everyone just calculates how much do miners use to mine Bitcoin and no one adds any other data for running the network. That is for a good reason. No one knows what devices are being used by individuals that use any crypto.
So, if you use node data you have that number already from article above. It’s 0.0006 GWh times about 3000 stake pools that equals 1.8 GWh to mint blocks and secure the ledger. That would be a fair comparison to same type of metrics they use when they say that Bitcoin miners use 91 Terawatts (which is 91,000 GWh). Which is about 56,000 times more then Cardano stake pools.
The number of 6 GWH per year may be an extrapolation of how much the whole network may consume when you include all the wallet nodes and average hardware used to make a transaction. However, if you are looking for straight comparison to how they calculate for all other cryptos then you just add up the network nodes that are actively used to make the network function.
There is an article by Cardano foundation on this forum confirming 6 GWh calculation while still acknowledging that Bitcoin calculations are just total of miners usage, while 6 GWh is total for whole Cardano (at the time). Direct quote: " In Bitcoin’s and other proof of work protocols, 99% of the energy consumption is used to just select a block producer. Cardano uses a proof of stake protocol, much more energy efficient. In comparison, Cardano uses only six gigawatt-hours of energy annually compared to 115.85 terawatt-hours used by Bitcoin."
Here is a link to official Cardano Foundation post:
Hope this helps 