@mfirestar the biggest power draw will be your GeForce GTX 1080 Ryzen 5 2600 at about 180W. Add about 5 Watt to 30Watt for your motherboards CPU (depends on the CPU) and about 3 watts per case fan. The motherboard will use more wattage depending what else you have connected in the expansion ports. Next, you will need to add your drives. Typical HDD is about 5W to 10W or SSD at about 2W - 3W. I can't see your computer using more then 350W to 400W. I would figure about 2.5-3 hrs of usage for a kWh
The harder you play and the hotter your computer gets, the more power you are using :-)