It's not. It still uses proof of work, for now at least. They say they want to implement proof of stake. THAT will be interesting, but I want to see if they ever get there.

There was an interesting article "Nothing is cheaper than proof of work"[1] that talked about both proof-of-stake and using miners to heat your home. Basically, if you decide you are willing to pay $9 to make $10 back, then discover you are additionally saving $1 off your heating bill, you will logically be willing to pay up to $10 to make $10 back + $1 in savings.

But, the main point of the article was that "proof of stake" is basically selling liquidity (exactly like bonds) and, to get the same job done, the cost of that liquidity won't end up being any cheaper than the cost of the electricity it's replacing.

The Ethereum Foundation has published a response [2].

[1] http://www.truthcoin.info/blog/pow-cheapest/

[2] https://github.com/ethereum/wiki/wiki/Proof-of-Stake-FAQ#doe...

Using electricity creates negative externalities in the form of physical resource consumption, though.

>They say they want to implement proof of stake. THAT will be interesting

what's so interesting about that? there are plenty of proof of stake coins already.

20 billion dollar more in market cap makes it a little bit more interesting than other coins that dont have that market cap, there's more at stake

Unfortunately not, but it's one of the premises of HashGraph (https://hashgraph.com).