The modern Xbox consoles have built in power supplies, but if you're still on the old 2013 model, you have a few options if you need a replacement.
The Xbox One S and Xbox One X have built-in power supply units, but if you're using a 2013 model Xbox One and need a power pack replacement, you have a few options that can sometimes be cheaper than Microsoft's official power brick.
Full story from the WindowsCentral blog...