Energy v cost, do people really not know the difference?

[Harry Bloomfield]

I went round my sons and my daughters homes a while back when this very discussion cropped up, in fact it cropped up originally in our house when daughter wanted TV on and asked for new remote batteries as we power down almost everything apart from PVR 's, router, dect phones, usb 13A sockets, outside PIR's
In my daughters house there were over 100 items either in standby or otherwise consuming energy, 40A clamp on main tail shows standby ~2A ~11KWh/day
In my sons house around 70, ~1A / 5.5KWh/day
In our house I think it's 10, ~ 40mA / 240Wh/day - I feel this is a bit low for mine but I used a very cheap meter with only 2 decimal places so potential for greater error at such a low current but this is more about comparisons rather than definitive values.

Here, I can log in and see what it suggests my base load is. I assume it watches my consumption, to see what the minimum falls to, likely during the night. It generally reports that as around 60w, all the things, which consume round the clock, on stand-by. Total daily consumption is 6 to 7kwh, varying little, between winter and summer. The 60w, is PIR's, routers, usb chargers, smart plugs, plus TV's, microwave on stand-by.

 

[Harry Bloomfield]

Indeed - but I suppose that a microwave oven might get closer to that truth than almost anything else, since it's probably one of the very few household appliances which (in just a tiny proportion of cases) may be left on standby continuously but virtually never used.

Our microwave, if your turn it off, insists on you setting the time, before it can be used. The regular use it gets, would turn this into a real chore.

I realise I have around a 200 watt load, which I can't explain.

You seem to be on Octopus, use the app, to see what it thinks your base load is.

That does rather surprise me - morqthana's reported experience is far more as I would have expected. What material was the kettle made out of, and how heavy was it in comparison with the pan?

Kettles are normally equipped with a lid, pan lids are optional. A lid help retain most of the heat, so if one is not used on a pan, it could make a drastic difference to the outcome of this comparison. A fitted pan lid, makes a massive difference to the energy input needed, when you are simmering food, and to the amount of moisture put into the kitchen.

 

[big-all]

Indeed and, given that the microwaves essentially only heat water molecules, I imagine that it probably is the water content of the food which is the most important factor. Compared with other methods of heating/cooking food (e.g. a conventional oven) a microwave oven would presumably be pathetic for trying to heat very dry foodstuffs

I agree, since the standby power is so trivial in comparison with the 'in use' power. However, the principle I mentioned still holds - a member of my family "doesn't really believe in microwaves ovens", but was given one as a present, and probably just uses it for a minute or two once every several months - so the standby power consumption might, in her case, be a bit closer to her 'in use' consumption

sugars and fats attracts energy far more than water in a microwave
tried an experiment to boil a cup off water
plastic kettle 2200w and 900w micro boil time about 30% longer but as the micro was about 1700w input kettle gets it but only iff it can boil only a single cup

 

[ericmark]

That does rather surprise me

I admit it was not what I expected, kettle likely one of these

and pan something like this

the pans were new, as had to change them when we got the induction hob, and the kettle was under 3 kW and the heat area was 3 kW, so the kettle did use slightly less at 2.7 kW v 3 kW, but still quite close.

I look at the energy report which has to be done before selling a house, first on the list, was to insulate the floors, and they gave the approx cost, and saving, which would take around 100 years to break even. How stupid can one get?

The swapping bulbs to LED, yes, that likely pays for its self in the summer, but once one reads the first daft idea, the report is binned.

The problem is, once one sees a daft statement, one either ignores the rest, or takes it with a pinch of salt.

The fridge/freezer is the hard one.

That is a lot of money, if we consider it will last 15 years, then £43 per year. And rated at 270 kWh per annum. So at 30p/kWh that's £81 running cost, so before it is worth swapping the kWh per annum will need to raise to 400 kWh. The figure changes depending on how many years it is likely to last, but the point is the reason to change is more down to it not keeping food cold enough as the motor is running full-time, to the cost of running it.

But select a cheaper model, and the point where it is worth renewing is maybe when it costs 350 kWh/annum. But to even know when it is using 350 kWh per annum, one needs to use an energy meter, but we are not going to wait a year to work out running costs, we are looking at renewing 959 watt-hours (350 kWh/365) and good at 740 watt-hours per 24 hours.

So we look at our smart meter, mine shows zero. My solar software tells me I am charging the battery at 900 watts, and using 279 watts, but the smart meter, reminds me of a chocolate fireguard. Don't talk about doing the gardening at night, would not want to live next to her with all the flood lights she would need to do gardening at night, how daft can one get?

 

[JohnW2]

Our microwave, if your turn it off, insists on you setting the time, before it can be used. The regular use it gets, would turn this into a real chore.

Yes, a lot of cookers and ovens are like that. Our microwave doesn't have a clock. It's display goes blank after a minute or two oof non-use, and then springs back to life if one opens the door.

Kettles are normally equipped with a lid, pan lids are optional. A lid help retain most of the heat, so if one is not used on a pan, it could make a drastic difference to the outcome of this comparison. A fitted pan lid, makes a massive difference to the energy input needed

Indeed - but I don't think that explains eric's findings, because ...

Kettle 2.7 kW and the induction hob 3 kW, and we filled the kettle to mark poured in into a pan with a glass lid, refilled kettle, both turned on together and took near exact same time to boil.

 

[Lower]

We've not long had a smart meter fitted, which tells me that our house consumes an average of 100w when we're out and all the lights are off.

That'll be the router, wifi repeaters, smart devices, Ring Camera's etc. I've excluded the blips where the fridge or freezer kicks in.

I was pleasantly surprised as i thought that 100w isn't very much. Until i considered that it was the same as leaving a 100w light bulb on all day, every day, and it drives me potty when my family leave lights on!

 

[ericmark]

which tells me that our house consumes an average of 100w when we're out and all the lights are off.

You're lucky, mine shows zero most of the time. But the only way to work out where the power is going, is to watch the meter and turn off MCB/RCBO for each circuit. Clearly, the in home display needs to be battery powered.

I use either the clamp-on meter or the plug in energy monitor the clamp-on shows me it is a ring final which is using most of the back-ground power, I see the reading drop as I switch it off. The freezers on their own supply, not through the consumer unit, but I have failed to date to find out what is using the power.

Sky box is one item which does not seem to comply with the 1 watt or less on stand-by.

 

[JohnW2]

We've not long had a smart meter fitted, which tells me that our house consumes an average of 100w when we're out and all the lights are off. ... That'll be the router, wifi repeaters, smart devices, Ring Camera's etc. ... I was pleasantly surprised as i thought that 100w isn't very much. Until i considered that it was the same as leaving a 100w light bulb on all day, every day ...

... but that's not 'standby'. One obvious cannot expect to 'run' things like routers, WiFi repeaters, Ring cameras etc. continuously without their using significant amounts of electricity. Fortunately, all these microelectronic devices use very little electricity - with the technology of a few decades ago, it would bbe a much more worrying issue!

 

[Harry Bloomfield]

plastic kettle 2200w and 900w micro boil time about 30% quicker but as the micro was about 1700w input kettle gets it but only iff it can boil only a single cup

For my 50/50 milk/water coffee, the microwave is the sensible solution.

We've not long had a smart meter fitted, which tells me that our house consumes an average of 100w when we're out and all the lights are off.

Average, is not the same as the base load. The base load is the absolute minimum your house draws, when everything which switches itself off, have switched off and on standby - just the items which are on, drawing current constantly.

 

[ericmark]

Tested power use.
Immersion heater 142 watts
Cooker all switched off 11.5 watts
Rear Sockets 101 watts
Front Sockets 113 watts
Flat lights 11.5 watts
Flat sockets main 4.6 watts
Flat sockets kitchen 241.5
Flat cooker 170 watts RCBO faulty would not trip or reset.
Total 625 watts.
So flat sockets should have been around 40 watt, so more hunting needed. Solar shows 433 watts, but the reading are not that accurate due to on switching circuits off, and on again, some smart stuff auto switched on. Don't think I am any wiser as to what is using power. The start amps measured also shows 433 watts, so it seems items were turning on/off while I was trying to measure.

 

[JohnW2]

Average, is not the same as the base load.

I suspect that he did not literally mean "average" - but, rather, meant that the background consumption was usually about 100W

 

[Harry Bloomfield]

I suspect that he did not literally mean "average" - but, rather, meant that the background consumption was usually about 100W

That wasn't what was said, the problem with the assumption, is that even whilst out, and everything switched off, there are still items which cut in and out regularly, like fridges. The only way to really assess base load, is by checking the minimum figure recorded over a longer period.

'Base load', I define as all those small loads, which are on constantly, appliances on standby, TV's, routers, PIR's, microwave ovens.

 

[JohnW2]

That wasn't what was said, the problem with the assumption, is that even whilst out, and everything switched off, there are still items which cut in and out regularly, like fridges. The only way to really assess base load, is by checking the minimum figure recorded over a longer period.

Whilst that is true, I would suggest that items "which cut in and out regularly" are almost invariably fairly significant lods, which one would 'notice'. If 'most times one looks' (whilst nothing other than fridges/freezers etc. is 'knowingly switched on') the load is about 100 W (but some times much higher than that) then the chances are that the 'base load' is around that figure.

 

[Harry Bloomfield]

Whilst that is true, I would suggest that items "which cut in and out regularly" are almost invariably fairly significant lods, which one would 'notice'. If 'most times one looks' (whilst nothing other than fridges/freezers etc. is 'knowingly switched on') the load is about 100 W (but some times much higher than that) then the chances are that the 'base load' is around that figure.

I would suggest that a base load of 100w, is rather a lot, when even my base load, with all that I have running, is only 60w. 60w amounts to the equivalent of 240 modern appliances on standby, although not all will be on standby, like routers and repeaters.

 

[Koolpc]

All my appliances are on Hamster power. They are all connected up to 300 hamster wheels which are on the the go 24/7....massive saving in electricity...