var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope) {
  var vat = 0.23;
  
  $scope.tariff = {
    offpeak: 0.0946*(1+vat),
    peak: 0.1785*(1+vat),
    power:0.2895*(1+vat)
  };
  
  $scope.consumption = {
  };
  
  $scope.powerwall = {
    price: 3000
  };
  
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <link data-require="bootstrap@*" data-semver="3.3.2" rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css" />
    <script data-require="bootstrap@*" data-semver="3.3.2" src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.4.x" src="https://code.angularjs.org/1.4.0-rc.1/angular.js" data-semver="1.4.0-rc.1"></script>
    <script data-require="jquery@2.1.3" data-semver="2.1.3" src="http://code.jquery.com/jquery-2.1.3.min.js"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl" class="container">
    
    <h2>Tesla Powerwall Savings estimator</h2>
    <span class="label label-default">v0.1</span>
    
    <br><br>
    
    <div class="row">
      
      <!-- Inputs -->
      <div class="col-md-4">
        <h4>Inputs</h4>
          <form class="panel panel-default">
            <div class="panel-body">
              <div class="form-group">
                <label>Off-peak energy consuption (Kwh)</label>
                <input type="number" class="form-control" placeholder="1720" ng-model="consumption.offpeak">
                <p class="help-block">Yearly consumption</p>
              </div>
              <div class="form-group">
                <label>Peak energy consumption (Kwh)</label>
                <input type="number" class="form-control" placeholder="3969" ng-model="consumption.peak">
                <p class="help-block">Yearly consumption</p>
              </div>
            </div>
        </form>
      </div>
      
      <!-- Results -->
      <div class="col-md-4">
        <h4>Results</h4>
        <form class="well">
          <div class="form-group">
            <label>Energy bill estimate</label>
            <p ng-show="energybill">{{energybill=(tariff.offpeak)*consumption.offpeak + (tariff.peak)*consumption.peak + tariff.power*365 | currency}}</p>
            <p class="help-block" ng-hide="energybill">(nothing to show yet)</p>
          </div>
          <div class="form-group">
            <label>Yearly savings estimate</label>
            <p>{{savings=(tariff.peak-tariff.offpeak)*consumption.peak | currency}}</p>
            <p class="help-block" ng-hide="savings">(nothing to show yet)</p>
          </div>
          <div class="form-group">
            <label>Investment payback</label>
            <p ng-show="savings">{{powerwall.price/savings | number:1}} years</p>
            <p class="help-block" ng-hide="savings">(nothing to show yet)</p>
          </div>
        </form>
      </div>
      
      <!-- Config -->
      <div class="col-md-4">
        <h4 class="faded">Configuration</h4>
          <form class="panel panel-default faded">
            <div class="panel-body">
              <div class="form-group">
                <label>Offpeak Energy Price (per Kwh)</label>
                <input type="number" class="form-control" placeholder="0,116358" ng-model="tariff.offpeak">
                <p class="help-block">Default price is for Portugal's EDP</p>
              </div>
              <div class="form-group">
                <label>Peak Energy Price (per Kwh)</label>
                <input type="number" class="form-control" placeholder="0,219555" ng-model="tariff.peak">
                <p class="help-block">Default price is for Portugal's EDP</p>
              </div>
              <div class="form-group">
                <label>Contracted KVA (per day)</label>
                <input type="number" class="form-control" placeholder="3000" ng-model="tariff.power">
                <p class="help-block">Default price is for Portugal's EDP</p>
              </div>
              <div class="form-group">
                <label>Powerwall price</label>
                <input type="number" class="form-control" placeholder="1720" ng-model="powerwall.price">
                <p class="help-block">Battery plus installation</p>
              </div>
            </div>
          </form>
      </div>
    
    </div>
    
    <hr/>
    <div class="row">
      <div class="col-md-12">
        <span class="text-muted">
          <p>
            <span class="label label-default">1</span> 
            Assumes that the Powerwall can convert all the peak consumption into off-peak consumption. 
            <span class="label label-default">2</span>
            Default values mix USD and EUR. Feel free to adapt to your own currency. 
            <span class="label label-default">3</span>
            State incentives are not accounted for. You can do so by reducing the Powerwall's price. 
          </p>
        </span>
      </div>
    </div>
  
  
  
  
    
  
  </body>

</html>
/* Put your css in here */

.faded {
  opacity: 0.5;
}

.faded:hover {
  opacity: 1;
}