Quoted from Lhyrgoif:Unless you play your games 24/7 then you should power down between plays. The electricity bill isnt the real issue here but rather electrical failures and possibly a fire.
Call me paranoid but I always disconnet all my games physically through a single wall breaker when I leave the game room. This not only prevent fires in failing electronics but also eliminates any issues with electrical spikes/lightning strikes and such.
You can also improve the protection for machines by plugging them into an outlet strip with surge protection.
If there is a lightning strike in the area, the outlet strip could protect the machine from serious damage, assuming it does have surge protection.
Some outlet strips do not have surge protection, so check that out.
Most outlet strips also have a circuit breakers rated for 15 Amps, which likely will trip before the circuit breaker at the panel.