For my own calibration, approximate current energy use for a single transaction in various cryptocurrencies, compared with using Visa:
|Bitcoin||BTC||1,000,000||Hot tub, 150 hours|
|Ethereum||ETH||62,000||Nissan Leaf, 1.5 charges|
|Litecoin||LTC||19,000||Clothes washer, 8 loads|
|Chia||XCH||2,000||Dishwasher, 1 hour|
|Cardano||ADA||500||Computer & monitor, 1 hour|
|Dogecoin||DOGE||120||Humidifier, 1 hour|
|Ripple||XRP||79||Amazon echo telling 2 jokes|
|Visa||1.5||LED light bulb for 9 minutes|
|Nano||NANO||0.1||LED light bulb for 30 seconds|
- I got most crypto energy use from this roundup.
- For Visa, I used the figures from this breakdown, and this one, which agrees.
- For Bitcoin, I took a rounded figure roughly between those quoted on the above two sources (710kWh and 1,123kWh). A single figure precision is probably most appropriate anyhow. Update: The digiconomist article above is updated as the Bitcoin energy use increases over time with proof difficulty, and it's now at almost double the figure I quoted above, at 1,800 kWh/txn.
- For Chia, I did my own hacky calculation. Chia Power estimates 6MW in total is used by the Chia network, at current size of 4EiB. Meanwhile, Chia Explorer shows a hard-to-read graph which I'm eyeballing to get a rough average of 3,000 transactions per hour. 6 Megawatts divided by 3k per hour gives an energy use per transaction of 2kW.
- For Nano, I'm using commonly-cited figures in Reddit posts (yuk), but the math seems to hold up as far as I can see.
- For equivalent household energy uses, I used this and this.
Notable standout here is NANO, which actually has an order of magnitude lower energy use than Visa. There are other low-energy use cryptocurrencies in this bracket, such as IOTA and HBAR. They face some criticism from Bitcoin maximalists that reducing energy use undermines the value proposition, or reduces security. But to my layman's ears, these arguments don't hold water. Certainly communities like NANO seem much more open to honest discussion of NANO's shortfalls than most crypto communities, which is a healthy sign, and it makes me inclined to trust their counter-assertions that NANO's security is really OK.
Something's not quite right here though. The Chia whitepaper estimates 10,000 times better energy efficiency than Bitcoin, by my figures above only show 1,000.
They probably know how to calculate this better than I do. So perhaps my figure for Chia is high? I understand the value per transaction will come down as Chia starts handling more transactions, which seems reasonable. Perhaps the white paper refers to that future hypothetical efficiency?
On the other hand, many of the other cryptocurrencies listed above will become more efficient in the future too (e.g. Bitcoin is in the process of deploying its lightning network, which will reduce per transaction energy use.) So I think it's fair to leave the above figures as they are, as a snapshot of current reality.