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Posted

One of the biggest hurdles i face before pulling the trigger on a solar system is determining what is causing the outrageous energy consumption in my home. I think it am at risk of selecting an improperly sized solar setup if i can't get a handle on how much i am actually using at firstHouse is brick, split level, gas Hot water, Split system aircon (used 2-3 days a year), wood fire heating. We are a family of 3, I work from home, wife works locally, primary school aged child. Our average daily consumption is about 37kWh which seems outrageous to me. There is a variation of only 1-2 Kwh each quarter. Possible contributors I've considered are:

  • Pool pump - runs 1-2 hours a day - 6star energy rated
  • Underfloor heating in 2 bathrooms - set on a timer, only used in cooler months
  • Fridges - Standard kitchen fridge, ancient minibar fridge outside, wine cabinet that runs at 12-14 degrees
  • Lights. mix of halogen , flouro and conventional energy saving - all being replaced with LED in next 3 months
  • Espresso machine
  • Induction cooktop
  • Some kind of weird energy leak to nowhere 

I've thrown a power meter on the fridges and pool pump which appear to not use much at all. Would be happy to hear any ideas as to a) what you would consider normal usage for the above and b) what could be causing my excessive usage.

Steve

 

Posted

Steve, based on what you claim to be running, that level of power usage is ridiculously huge!

Your pool running hours are very low. Normal pool filter run times should be six to eight hours in Winter, and seven to ten hours in Summer.

 

Also, are you sure your bills are 'Actual Read' and not 'Estimate' ?

 

Cheers,

Jason.

 

Posted (edited)

Sorry, pool runs for  1-2 hours a day when not in use May - Oct, 4-6 Nov to April. 

confirmed it was an actual read per the latest statement. The 3 meters also closely match what was on the statement so i am confident the readings are real. Unfortunately.

 

Is it possible the meters themselves could be reading higher than they should? (clutching at straws here)

Edited by Jone5y
additional Q
Posted (edited)

Steve, it really helps to do an audit.

Get a spreadsheet (or a bit of paper) and go to every room, and every space, inside and outside your home. Write down every item in each space that uses electricity, and its Wattage (W).

Next write down whether it is:

1. Always on

2. On standby. If on standby, write down how many hours per day it's turned on, that's your 'on' hours. Twenty four minus that number is your 'standby' hours.

3. Only on when switched on (such as a lamp). Write down how many hours per day it's turned on.

 

That's a good starting point to finding where your power goes. Do that and post your results here and we can work it out.

 

Cheers,

Jason.

 

Edited by koputai
Posted

Not sure what type of power meter you have, but see if you can monitor after each circuit-breaker/fuse/RCD.

If your power meter is not capable, see if your local electrician can do it for you. Then compare with what is going in. 

If the power equation doesn't balance (ie. power in = power out = power displayed on 'smart'' meter), then you have a serious fault with the smart meter. There was a recent case on one of the current affairs shows that told of a household with a wildly inaccurate smart meter.  Compensation?  Well that's where the problems began.....

Posted

Lots of good ideas above.  Another option for making sure it is not something like a highly inefficient fridge (or other appliance) is to grab one of these simple power meters that you can plug into the supply to any appliance and it will tell you watts / amps etc.  About $20 at your local hardware store.

Meter.jpg

Posted

Thanks for the suggestions all. I have one of the above meters from when i last looked into this so I'll dig it out again and compile the results in a spreadsheet to be posted here. If nothing obvious there I'll employ a sparky to assist with the meter 

 

Cheers

Steve

Posted
12 hours ago, gibbo9000 said:

Lots of good ideas above.  Another option for making sure it is not something like a highly inefficient fridge (or other appliance) is to grab one of these simple power meters that you can plug into the supply to any appliance and it will tell you watts / amps etc.  About $20 at your local hardware store.

A smart plug with built in meter is good option too.   You can monitor from a phone etc  which is handy if the socket isn't accessible to view (eg.  behind a fridge),   and I believe it'll log  history so good to work out consumption of intermittent loads.   

<$20 for this one.      

https://www.bunnings.com.au/arlec-grid-connect-smart-plug-in-socket-with-energy-meter_p0135442

Posted

Sorry if I missed it above. Are you with an energy provider who offers any analytics? 

We're with Powershop and it helped me establish where our usage was by looking at the hours of day we were using power. We are consistently around 45-50 kwH daily usage (family of 4 but large house, pool, servers (home business), ducted heating/cooling, commercial coffee machine, etc etc). 

I did some tests on the espresso machine and established I was better off turning it on (Z-wave power point) first thing in the morning and off late into the day after my last coffee. This used less energy than turning it on and off throughout the day and reheating the boiler each time. But it was still more cost effective to turn it off overnight rather than leave it on all the time.

My pool also uses 6-star pumps but then I have electric heating also, but even in non-use months I can still see where the circ pump turns on and off in daily usage.

Induction cooktops - these are power suckers. This causes the biggest spike of all each day and it is very easy to see when it turns on between 6-6:30PM and off again on daily usage. Fortunately, it's not an appliance that is used for long.

Most solar companies we spoke to reckoned we needed a 20kW system to cover our needs and they were probably right. That was simply not in the budget though, and our 12kW has definitely brought down our bills. The FIT is useless, so until my smart charger arrives I'm manually putting the excess on good days into the EV.

My advice aside from the knowledgeable people here - get quotes, quotes, and more quotes. Each time in the process you learn a little more and understand it all a bit better.

Posted

Dishwasher i had totally overlooked, clothes dryer is rarely used but I'll throw the meter on it next time it is.

Am part way through compiling usage numbers

Posted

UPDATE: Audit completed. Used a power meter to measure everything i could. Linky to google sheet here

Points of note:

  1. Bill shows average of 32Kwh over previous 15 months so the last 40kWh reading is higher than average. Covid probably played a role in that
  2. Some items such as cooktop and underfloor heating are hardwired, so data has come from known usage times and specification documents
  3. Underfloor heating seems comparatively low compared to other devices but is in line with online sales info
  4. Wine cabinet a huge contributor. I'll be troubleshooting its usage and/or finding an alternate solution in the future
  5. Little drinks fridge outside is using a comparatively high amount. Its almost as old as i am so that was somewhat expected
  6. There is an unknown standby contribution for a number of the devices measured. I suspect this would add up to another couple of kWh

Based on an average usage of 32kWh, there is still 6-8 unaccounted for. Inaccurate estimations, and occasional high powered tool usage (not included in table) would account for some of it.

I am more comfortable with "where it's all going" now and feel i'm in a better position to make an informed decision regarding the size of solar system required. Happy to hear your thoughts on the above and steps to reduce consumption (turning off at the wall will not be tolerated by the better half).

Posted

Nice work Steve.

 

Wine fridges are huge power users, as are a lot of small fridges.

I think there’s some errors in some items on your list:

The pool filter. 2 hours, 0.8kWh. The average size pool pump draws about 1kW. That’s 2kWh per day right there, more if there is a controller/salt water chlorinator rather than a simple timer running it.

 

Lounge AV. 6 hours, 1kWh. Just the standby on a TV and AV receiver is likely to be 0.5 to 1 kWh per day, let alone having it running for 6 hours.

 

Study. 10 hours for laptop and monitors at 0.6 kWh means they’re only drawing 60w all together. This seems too low.

 

Lighting. For the number of lights and hours, that works out to only 10w per light. That’s what an LED bulb will draw. Incandescents and halogens are more likely to be 50w each.

 

Anyway, you’ve started to get a good handle on what you’re using. It does make you realise which items are really costly to run.

 

Cheers,

 Jason.

 

Posted

Thanks for the reply Jason.

For the low readings I measured for 2 hours with the units active and multiplied the kWh shown on the meter by the avg daily usage. I'll retake some readings to be sure. Wherever multiple devices were used; AV, pump and chlorinator etc, the meter was placed between the power outlet and powerboard so all devices were measured concurrently. As for the lights, they are 10W energy saving bulbs so that made sense to me 🤷‍♂️

 

The wine cabinet did surprise me given the temp it runs at compared to a conventional fridge. I guess the humidifying is what makes the difference. The need for humidity is largely removed now that most wine is not under cork closure.

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