to be fair I think modern tumble dryers are much less energy hungry than they used to be, plus they are not terribly expensive to buy. you would obviously all have to agree not to put heaps of drenched towels in there for two hours to dry, just limit the use a bit and I would have thought it would be okay. You will all have to agree though, or you will end up paying a portion of the electricity for its use that you dont even use.
if it was me I would definitely have one, it means you have your stuff dried faster and more thoroughly, if you remove it promptly your stuff will need much less ironing too.