So, now that you have that working I’ll throw in a little wrinkle.
The UIs will show kW but the Item’s state will still be W and therefore the charts will still show the value as W and in your rules you’ll get the state as W.
If you really only want kW and you want kW everywhere, add the unit metadata to the Item and set that to “kW”. Then the value stored by the Item will always be in kW. If a rule or the binding sends the Item a value in W, it will be automatically converted to kW before updating the Item.