Depend on area, there is some area for electricity is way too much, sometime gas power is cheaper, solar in my area are petty good but in other area might be costy, along wind power, I think wind power is very costy than solar panel where I from.
overlay in steam turn off and steam offline with no internet might run game better, never had to worried to hurt your friend feeling when you are not in mood to play, they would see you offline.
Bheasman, good friend would might said "I'm unable to play same game you play, I need some time alone, but will hang out with you other time!"
do not telling them this "I don't want to play with you" meaning you don't want to play or hang out with them, show you are not good friend and not way to deal with that, and it's lack of compassion.