yes, Smart Lighting is the answer.
1 Add Smart App
2 select “Smart Lighting”
3 inside the smart lighting app select “New Lighting Automation”
4 select “Which devices do you want to control”
5 select the device!
6"What do you want to do?" Turn off (*this must be done in order to proceed)
7 select “select Trigger” “power Allowance”
8 Enter Minutes when the device should turn off.
That’s it
Good Luck, hope this helps
How things have changed in the past year since this thread was created. While Smart Lighting may have been the smart choice in this instance, it is also on it’s last legs. Smart Lighting will be phased out at some point in the coming months as ST continues the shift to Automations and Rules API.
If any user installs Smart Lighting, please be aware it may be for a short period of time that you can use it. 
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And in this particular case Automations now handle ‘Power Allowance’ very well if you write them as if device is on and stays that way for x minutes then turn off the device.
webCoRE users ought to be thinking twice about installing it too.
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I’ve been advised of the following a couple of weeks ago while in correspondence with ST…
“SmartLighting isn’t going anywhere right now. We know that’s an important SmartApp for users which is why much of the functionality in it has already been added to local execution via Rule API.”
So maybe a lifeline for us who prefer SmartLighting to get things done
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