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Crill(Newbie)Newbie
24 July 2024

Hi, the ATO website gives an example of how to calculate the KWH usage for Ben who has a separate work from home office with aircon running when he is working from home.


The example is not clear on how the kw per hour is calculated. In the example the air con unit is a 3.5kwh capacity with an end result of 1.09 kw per hour usage estimate. How is this usage calculated based on the energy efficiency rating.


for example, if a unit has a 15kwh capacity and an EER of 3 does that mean it is calculated to cost 5 kWh to run?



Example: electricity for cooling and heating

Ben works at home several days per week and keeps a record of the total hours he works from home. His record shows he worked a total of 768 hours from home in 2023–24.

When he works from home, Ben sits in a separate room of his house and always uses the air conditioner in the room when he is working. His air conditioning unit is small with a 3.5 kilowatt (kw) capacity. Based on the unit's energy efficiency rating, the unit costs Ben 1.09 kw per hour to run.

Based on his electricity bills, Ben pays 27.81c per kilowatt hour (28 c rounded up) for electricity.

Ben calculates the cost of cooling and heating for the room he uses when he is working from home as:

1.09 kw per hour × 0.28 per hour = 30.52c per kw hour

768 hours × 30.52 c = $234.39.


2,141 views
4 replies
2,141 views
4 replies

Most helpful response

Most helpful replyATO Certified Response

AriATO(Community Support)Community Support
ATO Certified Response5 Aug 2024

Hi @Crill


The example you have referred to for calculating electricity for the Actual cost method is based on Ben having information about the actual kilowatts (kw) per hour his air conditioner uses rather than him calculating it himself. As the example doesn’t make that clear, we will look into updating it. 


The kilowatts (kw) or watts per hour that an electrical appliance or light uses can generally be found in the manufacturer info, on the product or the star energy rating label or by searching the internet. If that info only provides you with the watts that your appliance or light uses rather than kw, you can covert this to kw per hour by dividing the number of watts by 1000. For example, if the energy consumption is 2,000 watts, then the appliance uses 2 kw per hour (2,000 ÷ 1,000).


For more info on energy ratings and the cost of running appliances refer to the link.


All replies

AriATO(Community Support)Community Support
31 July 2024

Hi @Crill


We're looking at this a bit more closely. Stay tuned.

friendlyfire(Initiate)Initiate
20 Nov 2024

I had similar questions, but about a ducted gas heater and found this thread. To be frank you're going to have to look at this a lot more closely, not a "bit" more closely. The 0.67 per hour method is not fit for purpose with gas at the price it is (thanks to John Howard for being asleep at the wheel throughout tenure as PM).


The gas/elec consumption found in the specs of an aircon or heater alone are also not good enough to calculate actual consumption. We can't just multiply max consumption by time worked in office. My gas heater switches itself on and off as needed to maintain a preset temp.


You need to do some proper thermodynamic studies in scenarios similar to real life to provide us some useful consumption rates to work with. We need you to account for the energy efficiency rating of devices and keep up with developments in technology. We need clear advice about impact of deduction from other people in the house (Lee's lounge room example is useless for this - on what planet would anyone try to get work done in the lounge while spouse and kids are watching TV?).


Similarly we need to change policy on ratio of work area to heated/cooled area. If I have to heat the family room to heat my office because of duct location then why is family room non-deductible, even if I'm alone in the house? It's silly and ignores basic physics.


Is there some sort of ETA on when all this is going to be cleared up? Until then we're just plucking numbers out of thin air to make this deduction.


Cheers,

James


AnitaATO(Community Support)Community Support
28 Nov 2024

Hey @friendlyfire,


Great feedback. We are always open to feedback and ways we can improve our services.


However, in this instance your best to reach out to your local member of parliament. They're the ones that impose the rules and regulations around the rates to use and what you can and can't be claimed.

Most helpful replyATO Certified Response

AriATO(Community Support)Community Support
ATO Certified Response5 Aug 2024

Hi @Crill


The example you have referred to for calculating electricity for the Actual cost method is based on Ben having information about the actual kilowatts (kw) per hour his air conditioner uses rather than him calculating it himself. As the example doesn’t make that clear, we will look into updating it. 


The kilowatts (kw) or watts per hour that an electrical appliance or light uses can generally be found in the manufacturer info, on the product or the star energy rating label or by searching the internet. If that info only provides you with the watts that your appliance or light uses rather than kw, you can covert this to kw per hour by dividing the number of watts by 1000. For example, if the energy consumption is 2,000 watts, then the appliance uses 2 kw per hour (2,000 ÷ 1,000).


For more info on energy ratings and the cost of running appliances refer to the link.


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Actual Cost method - how to calculate air con hourly usage with Kwh and Energy Efficiency Rating | ATO Community