My house uses 20kWh of electricity a day -- why so much?

alexanderalexander

My household comprises me, my wife, and our 11-month-old son. 

I have seen that our electricity bill has been quite high recently, and having examined it it looks like we're using around 20 kWh of electricity a day -- which is a lot for a small household. I can't, however, work out where it's all going.

We do have an electric oven/grill, which is probably the biggest single consumer of electricity as we use it fairly frequently, but we don't have a tumble dryer and our heating/hot water is gas powered. Other than that, we just have the standard range of appliances. We have low-energy lightbulbs throughout and try to switch things off.

Our wiring is very old (we will be getting it re-done when we renovate next year) so I was wondering whether there is even any possibility that it's somehow leaking electricity, but I can't see how that might actually be the happening in practice!

Does anyone have any ideas about what's going on? Could it even be the case that our meter is faulty?

Robin9

Top of the list will be the shower if it is electric?

Is the 20 kWh  coming from your own readings   or from Estimated bills?


Do a room by room audit - everything electric - include the loft, shed, garage, fish tank, garden pond ?

Gerry1

Start by doing the Meter Sanity Test.

bluelad1927

Is there immersion switch on your water tank that is switched on permanently?

JSHarris

My experience of monitoring our electricity usage carefully for years is that it's dominated by things that are on 24/7, particularly anything that gives off heat.  Cookers are surprising low down the list of things that cost a lot to run, as they aren't normally on for long and when they are on they tend to draw power in short bursts.

If there was a wiring fault anywhere then the wiring would be getting warm and would most likely have failed somewhere by now, so I'd rule that out.  Check everything that's on all the time and see if you can do without it.  

TVs are often relatively high energy users if on for long periods, so check to see if yours has an energy saving mode and if so adjust it down if you can.  Not unusual for a TV to draw anything from 100W to 200W, so could account for maybe 10% of your daily usage, perhaps more if it's on a lot.

PCs and monitors are much the same as TVs, so turning them off, or making sure they are in sleep mode, with the monitor turned off, can save about the same as turning the TV off.

In general, wander around feeling for anything that feels warm to the touch, as that's an indicator that it's consuming power.  Also check your fridge and freezer, if iced up or faulty these can use a lot of electricity.  The clue is to listen to it and see if the compressor is running for a long time.  Should only run for ten minutes or so every 30 to 60 minutes, any longer and it may have a fault.

Finally, if your house isn't on mains drainage but has a treatment plant then that can be a source of around 1kWh or more per day of consumption.  We're in this situation and I managed to find an alternative blower pump that was much more efficient.  Just making that change halved the plant running cost.

dealyboy

Do you have a smart meter? If so it should be fairly easy to monitor and isolate usage.

Robin9

bluelad1927 said:

Is there immersion switch on your water tank that is switched on permanently?

This is something which is often suggested but I wonder if it can be at all significant ?   Some gas heated houses with combis wont have one and modern hotwater tanks are so well insulated that I would guess they would heat from cold in a couple of hours and use very little in maintaining that

JSHarris

Robin9 said:

bluelad1927 said:

Is there immersion switch on your water tank that is switched on permanently?

This is something which is often suggested but I wonder if it can be at all significant ?   Some gas heated houses with combis wont have one and modern hotwater tanks are so well insulated that I would guess they would heat from cold in a couple of hours and use very little in maintaining that

We have electric water heating, as we don't have gas, oil or solid fuel.  There are two of us and our hot water uses between 2.8kWh and 4kWh per day.  Almost all of that is shower hot water consumption. I always time my shower every morning, target is to be in and out in less than three minutes.  Sometimes I can be done in two minutes, but it can be up to four minutes if I'm also washing my hair, so costs more.

Rodders53

Robin9 said:

This is something which is often suggested but I wonder if it can be at all significant ?   Some gas heated houses with combis wont have one and modern hotwater tanks are so well insulated that I would guess they would heat from cold in a couple of hours and use very little in maintaining that

My modern 210 litre unvented HW tank has a daily standing loss figure of 1.95 kWh.  That's when not using any water from it.  Mine is not atypical for the heat loss from an unvented tank of that size.

The maker quotes a reheat time of 175 minutes for the 3kW immersion heater - let's call that 3 hours on so 9 kWh - if we use all the hot water from it.  {It takes 23 minutes to reheat via the indirect loop and oil boiler - but will be the same 9 kWh of energy.}  One seldom uses all the water though.

If one did use a tank full each day then that would be 11 kWh if on the electric immersion.  Potentially pretty significant I'd say.  It all depends on how much hot water is used in the home.

Robin9

Thank you @Rodders53 - lets wait and see if the OP is using his immersion rather than the gas boiler.

QrizB

Rodders53 said:

It all depends on how much hot water is used in the home.

Yes, but let's not mix up hot water use (which we all agree can take a lot of energy) and "leaving the immersion heater on".

Rodders53 said:

My modern 210 litre unvented HW tank has a daily standing loss figure of 1.95 kWh.  That's when not using any water from it.  Mine is not atypical for the heat loss from an unvented tank of that size.

So, if you use no hot water at all, your tank will leak ~2kWh a day. It will leak those 2kWh whether you switch your immersion heater on for one hour, or for twenty-four.

Rodders53 said:

The maker quotes a reheat time of 175 minutes for the 3kW immersion heater - let's call that 3 hours on so 9 kWh - if we use all the hot water from it.  {It takes 23 minutes to reheat via the indirect loop and oil boiler - but will be the same 9 kWh of energy.}

Using your numbers, if you drained the tank while the immersion and the oil boiler were both able to re-heat it, it would take about 20 minutes. It woud use ~1kWh of electricity and ~8kWh of oil.