Forums > General Discussion   Shooting the breeze...

Standby power

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Created by Harrow > 9 months ago, 18 Dec 2021
Harrow
NSW, 4521 posts
18 Dec 2021 9:07AM
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Anyone calculated how much standby power their house is consuming?

I got a time of use electricity meter installed recently and am able to download the historical usage data for each half hour. It seems we have a steady draw of around 220 watts 24/7.

So, that's 0.22 x 24 = 5.3 kWh per day. Our average electricity usage is around 16 kWh per day, so about a third of our bill is wasted on standby power!!

I'm suspecting the largest culprit is the sump heater in the ducted air conditioner. I'll switch that off tonight and see how much difference that makes on overnight power consumption. The wifi and cable modem are always both warm, so they must be chewing a bit of juice as well.

decrepit
WA, 12787 posts
18 Dec 2021 8:00AM
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Don't forget your fridge also runs at night. We got a shock back from a holiday, I'd turned everything off except the fridge. Over 3kwh a day is what it used. I'd expect modems etc to be less than a 100w but for 24hrs that could be 2.4kwh. Yep it all adds up

Harrow
NSW, 4521 posts
18 Dec 2021 11:19AM
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decrepit said..
Don't forget your fridge also runs at night. We got a shock back from a holiday, I'd turned everything off except the fridge. Over 3kwh a day is what it used. I'd expect modems etc to be less than a 100w but for 24hrs that could be 2.4kwh. Yep it all adds up

Good point. 3 kWh / 24 hours = 125 W.

I'll look at them individually, but also try turning both off for a couple of hours. It will be interesting to see just how much is being sucked up by all the other standby appliances that are effectively doing nothing useful overnight.

Mark _australia
WA, 23510 posts
18 Dec 2021 9:29AM
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Maybe if we want to reduce energy and save the planet, houses need a main switch inside that kills everything except for the fridge powerpoint. Put it next to the master bedroom and you flick it as you go to bed.

Bigger picture - I wonder about all the open fridges and freezers at the shops. Surely they use a ****load more power? Yes they have clever airflow going on but there has to be some loss.
Bigger picture again, the quest for waterwise has led to hot houses - surrounded by paving etc rather than grass and trees = much hotter. Where is the requirement for every new house to have eaves and a water tank? Too hard, easier for Govt to make some ads and hope for the best.

decrepit
WA, 12787 posts
18 Dec 2021 10:55AM
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roof colour is a big contributor, look how many black roofs are around.
And big trees don't necessarily use water, they can help increase rainfall.

Ian K
WA, 4162 posts
18 Dec 2021 11:52AM
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And the massive cars we get around in these days. For the dream of one day getting the time off and the petrol money together to do an Ask-the-Leyland-Brothers sort of expedition. Is that classified as standby power?

Don't know how much of a problem all this Co2 in the atmosphere is actually going to cause. But if it is problematic down the track and future youtubers look at old videos of life in the suburbs what will they think? All that energy burnt just because we can.

We look back at hunting buffalo from trains, just because they could, as a bit out there. Are we any different?

www.smithsonianmag.com/history/where-the-buffalo-no-longer-roamed-3067904/

Buster fin
WA, 2596 posts
18 Dec 2021 12:31PM
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You can purchase, or in some cases borrow from the library, a meter to calculate any device or appliance's draw. Makes your investigation a breeze Harrow.
FWIW, my home is old school floorboards on limestone foundations and the difference from a concrete slab in summer and winter is astounding. No heater used and only the occasional aircon. Am developing my own micro climate through my garden choices too.

CH3MTR4IL5
WA, 939 posts
18 Dec 2021 12:37PM
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I am not sure if its worth $85 but doubles as a smart plug - will measure your devices current usage

www.evehome.com/en/eve-energy

Harrow
NSW, 4521 posts
18 Dec 2021 5:26PM
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Buster fin said..
You can purchase, or in some cases borrow from the library, a meter to calculate any device or appliance's draw. Makes your investigation a breeze Harrow.
FWIW, my home is old school floorboards on limestone foundations and the difference from a concrete slab in summer and winter is astounding. No heater used and only the occasional aircon. Am developing my own micro climate through my garden choices too.

I already own a plug in meter as well as clamp meters, but I don't know how well they discriminate between between kvar and kW, whereas the meter on the switchboard is certified revenue class. The air conditioner doesn't plug into the wall anyway, as well as the oven, gas fireplace, gas water heater, etc., so couldn't measure them so easily.

Also, there's about 40 items around the house that are using standby power, some with plugs that aren't easy to get to. Switching off the aircon circuit breaker will let me measure the total power used by the rest accurately in one go. Only need to push a button and a spreadsheet of all the half-hourly usage data gets emailed to me.

Our house is also double brick and floor boards, built in 1918. The old part of the house is cool all day, I never need to run the aircon to cool my office.

Mr Milk
NSW, 3116 posts
18 Dec 2021 7:25PM
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Besides thermal mass from the double brick, have you got a higher ceiling? My dead dad had an office out west built in the late 19th century that was relatively cool in summer with a 12' ceiling which also had a movable exhaust vent.
It might be interesting to check the room temperature at floor and ceiling height to find the difference

Harrow
NSW, 4521 posts
18 Dec 2021 8:08PM
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Mr Milk said..
Besides thermal mass from the double brick, have you got a higher ceiling? My dead dad had an office out west built in the late 19th century that was relatively cool in summer with a 12' ceiling which also had a movable exhaust vent.
It might be interesting to check the room temperature at floor and ceiling height to find the difference

Only 10 ft ceilings. 3 deg C difference from floor to ceiling.

cauncy
WA, 8407 posts
19 Dec 2021 12:43AM
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Eppo told me he uses a fleshlight at night , does he mean flash light

Harrow
NSW, 4521 posts
19 Dec 2021 7:25AM
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I did a walk around the house this morning to see exactly how many items are always powered up because they have a built-in clock or remote control, etc. Even the typical stove or fridge these days is often computer controlled and has a touch panel display with a clock, so they're chewing power even when they're not running or being used. I got over 50 items and still might have missed a few. (I've included the smoke detectors and burglar alarm, not strictly standby but they're a constant 24/7 power draw). If everything only uses a couple of watts each, it's still gonna add up. Yesterday I was shocked how much standby power was being used, now I'm surprised it's not more!

decrepit
WA, 12787 posts
19 Dec 2021 9:26AM
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yep things just aren't designed to turn off any more, there's always part of them awake waiting for you to hit the remotes' on button.

decrepit
WA, 12787 posts
19 Dec 2021 9:43AM
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Buster fin said. >>>>FWIW, my home is old school floorboards on limestone foundations and the difference from a concrete slab in summer and winter is astounding. No heater used and only the occasional aircon. Am developing my own micro climate through my garden choices too.


Hmmm I think there's more to it than that. In Perth ground temp a meter down is 20c, so a concrete floor ties you to that. It's a much better conductor than timber, so feels cooler to bare feet, but actually warms the house in winter and cools in summer.
The thermal mass of the concrete stores suns heat in winter and night time cool in summer.
Our old house was designed on these passive solar principals. We had no airconditioning and no heating, just fans for the heatwave conditions when it didn't cool down over night. House hit 30.1 deg after a week of 40s, and got down to 17deg after a big cloudy cold spell with no sun. But average temp in summer was mid 20s, in winter low 20s.
Here's a monthly chart I made between 2005 and 2010, the only form of heating apart from sun coming through N facing windows, was the gas oven when Dot baked a cake.


Buster fin
WA, 2596 posts
19 Dec 2021 1:49PM
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I agree it's not that simple but I still think there's something to it. I converted the garage into a room and has floorboards over a slab. It's always hotter in there in summer and colder in winter...

decrepit
WA, 12787 posts
19 Dec 2021 3:13PM
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Buster fin said..
I agree it's not that simple but I still think there's something to it. I converted the garage into a room and has floorboards over a slab. It's always hotter in there in summer and colder in winter...


yea well you put floorboards in, that insulates the slab, you would have been better with tiles, that doesn't insulate as much, and helps tie you into that 20c.

Probably a big difference between old style houses and modern ones is ceiling height. Higher ceilings are cooler, gives the hot air somewhere to go.

A lot depends where you are of course, in the tropics, you don't want to tie into the ground temperature it's too hot, and you certainly wouldn't want to do it in permafrost!

Harrow
NSW, 4521 posts
19 Dec 2021 7:57PM
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decrepit said..
roof colour is a big contributor, look how many black roofs are around.

Makes you wonder how much installing solar cells might cool a house, just by shading the roof.

GavGav
VIC, 193 posts
19 Dec 2021 9:43PM
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Mark _australia said..
Maybe if we want to reduce energy and save the planet, houses need a main switch inside that kills everything except for the fridge powerpoint. Put it next to the master bedroom and you flick it as you go to bed.




I built a system that does just that. Press the "Goodnight" button on the side of the bed and it shuts down the power and lighting circuits I chose for that setting. But, with all that automation there is an additional standby power to run the system (350w). But super convenient when you go to bed!

With all these discussions, you guys might be interested in this FB group.
My Efficient Electric Home. www.facebook.com/groups/996387660405677/
Lots of info and discussions about how to make your home more efficient and comfortable, and to reduce your running costs!

myusernam
QLD, 6154 posts
20 Dec 2021 5:43AM
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At $0.24 a kwh not a lot. Take out the fridge and freezer probably a lot less. You could maybe switch on an energy saving option on the wifi for late at night? Very convenient when u cant sleep tho.

nicephotog
NSW, 276 posts
11 Jan 2022 7:52PM
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Harrow said..
Anyone calculated how much standby power their house is consuming?

I got a time of use electricity meter installed recently and am able to download the historical usage data for each half hour. It seems we have a steady draw of around 220 watts 24/7.

So, that's 0.22 x 24 = 5.3 kWh per day. Our average electricity usage is around 16 kWh per day, so about a third of our bill is wasted on standby power!!

I'm suspecting the largest culprit is the sump heater in the ducted air conditioner. I'll switch that off tonight and see how much difference that makes on overnight power consumption. The wifi and cable modem are always both warm, so they must be chewing a bit of juice as well.


Depends how much loss in the wire run to the house connection, can lose a Kw over 200 meters.
Over time ready components that control on off switches loss leak electricity e.g. the hot water service, oven clocks or lights, security lights, transformers in TV's and Computer power.
(switch off the background on the menu)
windsolarhybridaustralia.x10.mx/batterycalculatorAH.html

(don't (unless you are in the business of...) refer to the Tomcat project - the site is uneditable and project is replaced anyhow (on the billion to one chance that ever interested anyone anyhow, here is the new link drive.google.com/file/d/1gbz54O8aOUEFOdRa40ZlRM7AtpS4Uj_C/view?usp=sharing) )

tarquin1
954 posts
11 Jan 2022 5:12PM
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I know a guy that invested in smart breaker boxes for houses. It would keep track of times when things were used. Then after a couple of weeks it would turn things off at the breaker at times they were not being used. Not in a way you would have to reset the time and everything though. If you did want to turn something on you still could. They were too expensive and never really took off so the company stopped making them. It should be law that they are installed in new builds.
Yes the amount of electricity used on standby is crazy.

AquaPlow
QLD, 1064 posts
11 Jan 2022 10:41PM
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The central approach for monitoring sounds G8.
Alternate approach for daylight hours is solar panels. A modest battery system and U R covered. The ABC science podcast had interesting article on building the storage battery as an integral part of the wall - due to size although not as energy dense as Tesla style Lithiums very effective.

Without automation (lots of individual control plugs etc adds up). If you have the smarts and interest (hobby ) Arduino approach opens up a lot of control systems. A new house / re-wired house has a better chance of automation without the manual micro-management which I found to be a PITA.

A good rule of thumb is starting with the older appliances - their design concept more often than not did not aim to minimise stand bye power. The energy stars rating for the main white good appliances always attracted our purchasing eye (I am long time CHOICE subscriber - their advice helps for avoiding energy hungry items).
Once I discovered the standbye draw on an older Kogan flat panel made me ditch it always warm.

The by-product of the shading solar panels provide on covered roof area you mentioned has to be useful. Neighbour has 80-90% of the north facing roof covered 20-25 panels - he can only sell 50% of max output to the grid but has commented on being cooler. The panels can get too hot to operate at peak efficiency on flatter roofs if the install frame doesn't allow for adequate ventilation.

Solar gives me a way out re-stand bye power use as although constant and it adds up I like the benefits.

AquaPlow
QLD, 1064 posts
11 Jan 2022 11:07PM
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Decrepit loved that review..
decrepit said..

Select to expand quote
Hmmm I think there's more to it than that. In Perth ground temp a meter down is 20c, so a concrete floor ties you to that. It's a much better conductor than timber, so feels cooler to bare feet, but actually warms the house in winter and cools in summer.
The thermal mass of the concrete stores suns heat in winter and night time cool in summer.
Our old house was designed on these passive solar principals. We had no airconditioning and no heating, just fans for the heatwave conditions when it didn't cool down over night. House hit 30.1 deg after a week of 40s, and got down to 17deg after a big cloudy cold spell with no sun. But average temp in summer was mid 20s, in winter low 20s.


When built into roof space in 1920's Californian bungalow with old clay tiles for roofing (see daylight through no insulation) - I came to conclusion without replacing and insulating roof it was a deal breaker v.hard space to not always be running heat/cooling till found a plaster sheet manufacturer who stuck commercial freezer grade insulation panels on the back. The builder charged to handle but did a g8 install and was very thermally stable - soundproofing was added benefit. The hitch to this approach was cabling / power/light fittings had to burrow thru!! Double brick, solid plaster walls and ten foot ceilings downstairs where g8.



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Forums > General Discussion   Shooting the breeze...


"Standby power" started by Harrow