Mystery Energy Drain

thescouselander

So I was looking through our electricity energy usage as reported by our smart meter every 30 mins and for some reason we seem to have high energy usage between midnight and 2am - this is exactly the same every day.  I'm totally stumped at why this should be.  The energy supplier reckons the readings look accurate but we're all in bed by this time and everything is switched off.  We have gas heating and the house is generally very efficient as a new build - all outside lights are LED and I can’t think of anything that would draw that much power except for the Oven, Washing Machine, Dishwasher or Drier all of which are off overnight.

 

Does anyone have any ideas on what this is?  

Verdigris

Is there an immersion heater in the hot water cylinder? It may come on if the gas boiler is only set to satisfy the HWC at certain times. Check that it is switched off.

Swipe

Whatever it is, it doesn't look like a high power device so switch everything off tonight and monitor

QrizB

Curious.

If you trust your appliances to re-start in an orderly fashion, flip the main switch on your consumer unit before going to bed then see what the meter registers. But don't forget to switcvh it back on in the morning, and don't expect a mains-powered alarm to wake you up!

thescouselander

@Verdigris - yes we have an immersion heater although I've switched it off at the consumer unit in case that was the issue

@Swipe - yes, not a high power device but each bar is only 30 mins so at 0.5unit for each 30 mins that's a full kilowatt being drawn so it's not a low power device either. 

[Deleted User]

My money is in a fridge freezer. All homes have a baseload: the graph suggests c.100 watts. It is not an immersion heater. They are normally rated at 3kWs so the graph would show 1.5kWhs plus baseload in each 30minute period.

thescouselander

[Deleted User] said:

My money is in a fridge freezer. All homes have a baseload: the graph suggests c.100 watts. It is not an immersion heater. They are normally rated at 3kWs so the graph would show 1.5kWhs plus baseload in each 30minute period.

Maybe, it's brand new and A+++ rated but perhaps its faulty.  That said if it was the fridge freezer wouldn't it cause similar peaks throught the day? 

Tallerdave

Does the heating come on at night? That might account for some of the load.
My other guess would be things that you think are in standby but which are waking up to do some housekeeping - sky/virgin box, TVs, laptop, Xbox, PC, etc. 
Bearing in mind the baseload at that time of night you're looking for 350-400W.

thescouselander

Tallerdave said:

Does the heating come on at night? That might account for some of the load.
My other guess would be things that you think are in standby but which are waking up to do some housekeeping - sky/virgin box, TVs, laptop, Xbox, PC, etc. 
Bearing in mind the baseload at that time of night you're looking for 350-400W.

The heating is off now.  I don't think the sky box could draw much but the Xbox is a possibility. I've got a plug in energy meter so I'll set that up on the Xbox tonight.