diff --git a/resource/web/pc_overview.tmpl b/resource/web/pc_overview.tmpl
index cce2aad2..e66c0643 100755
--- a/resource/web/pc_overview.tmpl
+++ b/resource/web/pc_overview.tmpl
@@ -2,70 +2,53 @@
 
 <div class="row placeholders">
     <H1>Last 24 hours (kWh/5min)</H1>
-    <div id="min-power-chart" style="height:350px;"></div>
+    <div id="minute-power-chart" style="height:450px;"></div>
 </div>
 <div class="row placeholders">
     <H1>Last Week (kWh/h)</H1>
-    <div id="hour-power-chart" style="height:350px;"></div>
+    <div id="hour-power-chart" style="height:450px;"></div>
 </div>
 <div class="row placeholders">
     <H1>All History (kWh/day)</H1>
-    <div id="day-power-chart" style="height:350px;"></div>
+    <div id="day-power-chart" style="height:450px;"></div>
 </div>
 <div class="row placeholders">
     <H1>All History (kWh/week)</H1>
-    <div id="week-power-chart" style="height:350px;"></div>
+    <div id="week-power-chart" style="height:450px;"></div>
 </div>
 
 <script>
+
     $(function(){
-		chartData("min-power-chart", 
-				[
-				{ time: (Date.now()-24*60*60*1000) },
-				{{#minData}}  
-					{ time: {{.timestamp}}, "{{.id}}": {{.data}} },
-				{{/minData}}
-				{ time: Date.now() }
-				]
-		);
-		chartData("hour-power-chart", 
-				[
-				{ time: (Date.now()-7*24*60*60*1000) },
-				{{#hourData}}  
-					{ time: {{.timestamp}}, "{{.id}}": {{.data}} },
-				{{/hourData}}
-				{ time: Date.now() }
-				]
-		);
-		chartData("day-power-chart", 
-				[{{#dayData}}  
-					{ time: {{.timestamp}}, "{{.id}}": {{.data}} },
-				{{/dayData}}
-				{ time: Date.now() }
-				]
-		);
-		chartData("week-power-chart", 
-				[{{#weekData}}  
-					{ time: {{.timestamp}}, "{{.id}}": {{.data}} },
-				{{/weekData}}
-				{ time: Date.now() }
-				]
-		);
+		initChart("minute-power-chart", "?json&data=minute", 5*60*1000);
+		initChart("hour-power-chart", "?json&data=hour", 60*60*1000);
+		initChart("day-power-chart", "?json&data=day", -1);
+		initChart("week-power-chart", "?json&data=week", -1);
+
 	});
 
-    function chartData(elementId, data){
-        Morris.Line({
+    function initChart(elementId, url, time){
+        var chart = Morris.Line({
               element: elementId,
-              data: data,
+              data: [{time:0}],
               xkey: 'time',
-              ykeys: [ {{#sensors}} "{{.getId()}}", {{/sensors}} ],
+              ykeys: [ {{#sensors}} {{.getId()}}, {{/sensors}} ],
               labels: [ {{#sensors}} "{{.getUser().getUsername()}}: {{.getName()}}", {{/sensors}} ],
               continuousLine: false,
               pointSize: 1,
               postUnits: 'kWh',
               resize: true,
               hideHover: 'auto',
-            });
+        });
+        updateChart(chart, url, time);
+    }
+
+    function updateChart(chart, url, time){
+        $.getJSON(url, function(json){
+            chart.setData(json.data);
+        });
+        if(time > 0)
+            setTimeout(function(){ updateChart(chart, url, time); }, time);
     }
 </script>
 
diff --git a/src/se/hal/page/PCOverviewHttpPage.java b/src/se/hal/page/PCOverviewHttpPage.java
index 8019d9b3..48a0618e 100755
--- a/src/se/hal/page/PCOverviewHttpPage.java
+++ b/src/se/hal/page/PCOverviewHttpPage.java
@@ -41,26 +41,11 @@ public class PCOverviewHttpPage extends HalHttpPage implements HalHttpPage.HalJs
         ArrayList<AggregateData> hourDataList = new ArrayList<>();
         ArrayList<AggregateData> dayDataList = new ArrayList<>();
         ArrayList<AggregateData> weekDataList = new ArrayList<>();
-
         List<Sensor> sensors = getSensorList(db);
-        for (Sensor sensor : sensors) {
-            minDataList.addAll(AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.FIVE_MINUTES, UTCTimeUtility.DAY_IN_MS));
-
-            hourDataList.addAll(AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.HOUR, UTCTimeUtility.WEEK_IN_MS));
-
-            dayDataList.addAll(AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.DAY, UTCTimeUtility.INFINITY));
-
-            weekDataList.addAll(AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.WEEK, UTCTimeUtility.INFINITY));
-        }
-
 
         Templator tmpl = new Templator(FileUtil.find(TEMPLATE));
         tmpl.set("users", User.getUsers(db));
         tmpl.set("sensors", sensors);
-        tmpl.set("minData", minDataList);
-        tmpl.set("hourData", hourDataList);
-        tmpl.set("dayData", dayDataList);
-        tmpl.set("weekData", weekDataList);
 
         return tmpl;
     }
@@ -75,33 +60,40 @@ public class PCOverviewHttpPage extends HalHttpPage implements HalHttpPage.HalJs
         DBConnection db = HalContext.getDB();
         List<Sensor> sensors = getSensorList(db);
 
-        if (request.get("data").contains("minute")) {
+        if (request.containsKey("data")) {
             DataNode node = new DataNode(DataNode.DataType.List);
-            for (Sensor sensor : sensors)
-                addAggregateDataToDataNode(node,
-                        AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.FIVE_MINUTES, UTCTimeUtility.DAY_IN_MS));
-            root.set("minuteData", node);
-        }
-        if (request.get("data").contains("hour")) {
-            DataNode node = new DataNode(DataNode.DataType.List);
-            for (Sensor sensor : sensors)
-                addAggregateDataToDataNode(node,
-                        AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.HOUR, UTCTimeUtility.WEEK_IN_MS));
-            root.set("minuteData", node);
-        }
-        if (request.get("data").contains("day")) {
-            DataNode node = new DataNode(DataNode.DataType.List);
-            for (Sensor sensor : sensors)
-                addAggregateDataToDataNode(node,
-                        AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.DAY, UTCTimeUtility.INFINITY));
-            root.set("minuteData", node);
-        }
-        if (request.get("data").contains("week")) {
-            DataNode node = new DataNode(DataNode.DataType.List);
-            for (Sensor sensor : sensors)
-                addAggregateDataToDataNode(node,
-                        AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.WEEK, UTCTimeUtility.INFINITY));
-            root.set("minuteData", node);
+            if (request.get("data").equals("minute")) {
+                DataNode nowTime = new DataNode(DataNode.DataType.Map);
+                nowTime.set("time", System.currentTimeMillis()-24*60*60*1000);
+                node.add(nowTime);
+                for (Sensor sensor : sensors)
+                    addAggregateDataToDataNode(node,
+                            AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.FIVE_MINUTES, UTCTimeUtility.DAY_IN_MS));
+            }
+            else if (request.get("data").equals("hour")) {
+                DataNode nowTime = new DataNode(DataNode.DataType.Map);
+                nowTime.set("time", System.currentTimeMillis()-7*24*60*60*1000);
+                node.add(nowTime);
+                for (Sensor sensor : sensors)
+                    addAggregateDataToDataNode(node,
+                            AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.HOUR, UTCTimeUtility.WEEK_IN_MS));
+            }
+            else if (request.get("data").equals("day")) {
+                for (Sensor sensor : sensors)
+                    addAggregateDataToDataNode(node,
+                            AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.DAY, UTCTimeUtility.INFINITY));
+            }
+            else if (request.get("data").equals("week")) {
+                for (Sensor sensor : sensors)
+                    addAggregateDataToDataNode(node,
+                            AggregateDataListSqlResult.getAggregateDataForPeriod(db, sensor, AggregationPeriodLength.WEEK, UTCTimeUtility.INFINITY));
+            }
+
+            DataNode nowTime = new DataNode(DataNode.DataType.Map);
+            nowTime.set("time", System.currentTimeMillis());
+            node.add(nowTime);
+
+            root.set("data", node);
         }
 
         return root;
@@ -111,7 +103,10 @@ public class PCOverviewHttpPage extends HalHttpPage implements HalHttpPage.HalJs
         for (AggregateDataListSqlResult.AggregateData data : dataList) {
             DataNode dataNode = new DataNode(DataNode.DataType.Map);
             dataNode.set("time", data.timestamp);
-            dataNode.set("" + data.id, data.data);
+            if (data.data == Float.NaN)
+                dataNode.set("" + data.id, (String)null);
+            else
+                dataNode.set("" + data.id, data.data);
             root.add(dataNode);
         }
     }
@@ -122,7 +117,8 @@ public class PCOverviewHttpPage extends HalHttpPage implements HalHttpPage.HalJs
     private List<Sensor> getSensorList(DBConnection db) throws SQLException {
         List<Sensor> sensors = new ArrayList<>();
         for (Sensor sensor : Sensor.getSensors(db)) {
-            if (sensor instanceof PowerConsumptionSensorData)
+            if (sensor.getDeviceData() != null &&
+                    sensor.getDeviceData() instanceof PowerConsumptionSensorData)
                 sensors.add(sensor);
         }
         return sensors;
diff --git a/src/se/hal/util/AggregateDataListSqlResult.java b/src/se/hal/util/AggregateDataListSqlResult.java
index 3a5c972c..2f98554d 100755
--- a/src/se/hal/util/AggregateDataListSqlResult.java
+++ b/src/se/hal/util/AggregateDataListSqlResult.java
@@ -17,10 +17,10 @@ public class AggregateDataListSqlResult implements SQLResultHandler<ArrayList<Ag
 	public static class AggregateData {
         public int id;
 		public long timestamp;
-		public String data;
+		public float data;
 		public String username;
 
-		public AggregateData(int id, long time, String data, String uname) {
+		public AggregateData(int id, long time, float data, String uname) {
             this.id = id;
 			this.timestamp = time;
 			this.data = data;
@@ -76,10 +76,10 @@ public class AggregateDataListSqlResult implements SQLResultHandler<ArrayList<Ag
 
 			//add null data point to list if one or more periods of data is missing before this
 			if(previousTimestampEnd != -1 && previousTimestampEnd+1 < timestampStart){
-				list.add(new AggregateData(id, previousTimestampEnd+1, "null", username));
+				list.add(new AggregateData(id, previousTimestampEnd+1, Float.NaN, username));
 			}
 
-			list.add(new AggregateData(id, timestampEnd, ""+ (estimatedData/1000.0), username));	//add this data point to list
+			list.add(new AggregateData(id, timestampEnd, (estimatedData/1000f), username));	//add this data point to list
 
 			//update previous end timestamp
 			previousTimestampEnd = timestampEnd;