I have refuted this claim more than once. Bitcoin energy consumption is determined by both network hash rate and efficiency of the miners. The latter improves through time because of Moore's law and the first won't grow exponentially because of negative impacts of halving and price corrections that de-incentivize mining.

I could say, in mid-term we would be experiencing a significant drop in electricity usage of bitcoin network and in long term this figure will be many times lower than what it is today because there wouldn't be  enough issuance of new bitcoins.

In the current state of its development, bitcoin network is producing a commodity and like any other production process it consumes resources. In the future when this issuance/production is significantly dropped the energy consumption will drop comparatively.

PoW doesn't require energy explicitly for transaction processing. In my design of PoCW I have inserted a hashcash like feature to the system that allows wallets to take part in the security, such that in each halving this role becomes more important and eventually would be the dominant factor for securing the network. It is just one example of many possible improvements in bitcoin for confronting zero-issuance situation.

PoS alternatives are focused on transaction processing and remain silent about the issuance problem. Inflation in PoS is morally unacceptable and economically void. It resembles fiat money inflation. Even hybrid PoS coins are the same as long as they have issuance of new coins based on stakes.  

A PoS system without issuance is nothing more than a second layer protocol for bitcoin (one may suggest to understand LN as a PoS network on top of bitcoin) and with issuance, it is just a scam no matter how big and popular it is, it is a scam just like USD.

Ethereum community is a good example of how a decent ecosystem could be corrupted by PoS ideas:
Right now their big stake holders (Buterin and his Foundation on top) are imposing their short term interests regularly by adopting frequent hard forks to intervent issuance of ETH.

A coin, more than 75% pre-mined, now is actively politicized by the big shots to bump its price by any means and in the best interests of coin/stake owners.

Now, before PoS, they have trouble with miners because they need security which is still provided by miners. Once this coin is PoSed you will have a mafia on top of the system who is in charge of any critical decision including inflation rate without any objective factor to keep them on the track.

Any honest observer understands what I'm saying about the situation with Ethereum and the misery PoS infection has brought to its community and the inevitable failure of it in the near future. The failure that has been signaled already and is based on the subjective understanding of cryptocurrency that PoS enthusiasts are infected with.

According to this subjectivism, crypto is about solving a problem, monetary system, by means of computer and communication.
A reputation based system is what a junior programmer re-discovers every single day he feels confident enough to tackle this problem. Before bitcoin they were mainstream and now they are back in the name of PoS.

No matter what is the label, they have failed and will fail not because of this or that design flaw but because "monetary system" is not a problem to be solved, it is a socio-economic phenomenon that should be re-built. It is what PoW and bitcoin have managed to do, they have built a new monetary system by consuming energy and resources.