Kurt Shintaku's Blog

The Xbox One in standby mode uses 10-15.7 watts — the most of all next-generation consoles… and it’s always consuming that power 24/7. 

Enable "Energy Saving" mode to drop power usage to .4-.5 watts & save money on your electrical bill.

Read more below on how to do this &what the power consumption is for each Xbox console type:

• About power settings on Xbox One and Xbox Series X|S
  https://support.xbox.com/en-US/help/hardware-network/power/learn-about-power-modes