Even when you use company server it is still more efficient as it does not really matter where you use energy - on your pc or on commercial server. (In fact, I believe commercial servers are more energy efficient). Because those networks use a lot of energy in a short period of time but alternative is to use average amount of energy for much longer period of time. Of course it is not always like that and just to be clear: I do not have exact numbers but it is how I assume the situation
But when we are talking about energy I always think people who really care about energy that much should not use x86 processors and services like Steam or Itch as they run their software on big commercial servers. Because where to put the line?