Will I need to upgrade my power?

Will I need to upgrade my mains power?



This article has been adapted from an Energy Freedom Homes response to a client question.

The question

I'd be interested to know more about the recommendation to upgrade the mains supply to 63A. My electrician-friend said that all new houses have a 40A supply. I'm assuming this should service the needs of having an all-electric house. To upgrade seems like it isn't really necessary?

The answer

Most new homes on a single title will have a minimum supply of 63A and most new developments with multiple dwellings on one site will have a 40A supply.
 
New builds that do have a 40A supply are based on historic practices, rather than consideration for the move towards all-electric homes.
 
This is because they are still being designed for gas appliances, which means they require a lower mains supply.
 
The reason for the confusion and the response from your electrician-friend is partially because there is currently no industry-standard.

As we explain below, increasing the current for your mains supply will allow you to add more electrical appliances to your home without tripping your mains switch if multiple appliances are used simultaneously.

Does this mean you'll be tripping your mains switch all the time? It depends on the size of your home and your energy usage. If you have a small home or low gas/electricity bills based on usage, you might be able to avoid a mains supply upgrade. However, if you have a big home and use a lot of energy, you should consider a mains upgrade.
 
We are hopeful that in the future the industry standard will support all-electric homes to make this clearer for homebuyers, renovators and owners.

How to future-proof your home

To future-proof new build homes we usually suggest 3 phase power for single title and multiple dwelling situations.
 
This position is supported by Henley Homes, who are currently offering volume build solar all-electric homes1. All their homes have 3-phase as standard to support solar, induction, reverse cycle air conditioning and a hot water heat pump.

However, this type of upgrade to existing homes can be very expensive, so we'd recommend the following:
  1. Figure out which additional electrical appliances you will be adding to your home as part of your electrification plan,
  2. Speak with an electrician to find out if your existing mains supply will be sufficient based on your current electricity/gas usage and your planned upgrades.
Here is a crunching of the numbers to demonstrate why a larger mains supply could be important, using a scenario around dinner time when you might be cooking with the heating on:

Appliance

Current load

Toaster

10A

Kettle

10A

Oven

10A

1x5kw air con unit

4A

Induction cooker 60cm with 2 burners in use

20A

Other general appliances e.g. fridge and TV

10A

Total

64A

 

If we combine all these loads, we can see that the demand will significantly exceed a 40A supply, which will trip the mains switch. 

 

Because you are upgrading your home rather than building a new one, we suggested an upgrade to a 63A mains supply. We have two reasons behind this suggestion:
  1. The likelihood of a 63A mains switch tripping is much less than your current 40A mains switch, based on the upgrades that you want to make to your home.
  2. Upgrading your single phase will cost you less than changing to 3-phase.
Considering your budget, this is the best trade-off for cost/stability under your circumstances.

Summary

If your home's mains supply is 40A and you use a lot of energy with a mixture of gas and electricity, you will have to be very careful about appliance use in an all-electric home.
 
To enable usage of multiple appliances without danger of tripping your mains switch, you have the option to upgrade to 63A single phase or to 3-phase mains power.
Not everyone's circumstances will be that of this client, and as such, the recommendation may vary. For example, if you have a large house, high energy usage and an intention to purchase an electric vehicle that will be charged at home, we would suggest upgrading to the maximum possible single phase mains supply, and possibly 3-phase.

Next steps

Another important check for your electrics is your switchboard. Find out more with our article, "Will I need to upgrade my switchboard?"

To find out more about your other upgrade priorities to achieve Energy Freedom, head to our article, 'What's the next step to your Energy Freedom Home?'
 
Wondering what an Energy Freedom Home is? Have a read of our article, 'What is an Energy Freedom Home?'
 
Want to fast-track home electrification? Join an Energy Freedom Homes Masterclass and learn to identify your needs, gain expert installation advice, and meet trustworthy tradespeople. Check your Masterclass readiness now!

References

1 Henley. (2022). You can choose a solar all electric home. Retrieved  2023, from https://henley.com.au/offers/promotions/solar-all-electric-homes