stuff

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
   options: ['testtesttesttesttesttesttesttesttesttesttesttest'],
   selected: null
});

templates.application.hbs

 {{#power-select options=options
                selected=selected as |x|}}
            {{x}}
{{/power-select}}	

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-power-select": "^1.5.0-beta.0"
  }
}