Yes, Bitcoin is fucking greedy to begin with - especially considering the climate change problem. No, they are not wasting energy per-se in this instance:

> The country has more than 2,000 small stations, many of them sitting idle because of low wholesale power prices and an absence of state support.

That's not to mention the energy disposal problem that you have to deal with when the majority of your energy is renewable - POW is a good way to get rid of unused energy. Given that Bitcoin isn't going away, much like anything else where greed is concerned, this is a fantastic development.

> find a way to mine coins that uses less electricity

Attack SHA-256. That's the only option we have now. People sure-as-hell aren't going to move away from a tech which they believe is printing free money (I have some otherwise very smart friends who are mining coins with GPUs).