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Choosing a system size. why bigger is becoming the norm for solar system sizing (future proofing for EV charging, batteries etc).
The team of Brisbane electricians at Dillon and Kenzie Electrical have designed and installed hundreds of solar systems. We enjoy visiting your home to discuss the property but we also want to find out who you are and how you want your new solar system to work for you.
Some of the things we take into account are:
- Size, material and physical layout of the roof
- Where is the best spot for your inverter
- How does your switchboard look? Does it need a minor or major upgrade to comply with current standards?
- Do you have single or three phase power to your property?
- How do you use your power today but also how do you see the household dynamics changing over the coming years?
- Do you plan on having an EV the next time you upgrade your car?
- Are you considering a battery now or for the future?
All of this helps us design a quality system that is sized correctly for your needs.
When designing your new solar system we are controlled by some limitations set by Energex in South East Queensland.
- A property can only have a maximum of 10kW of inverter capacity per phase, single phase 10kW, three phase 30kW. This includes your solar inverter and battery inverter if it is connecting via AC Coupling. For more information regarding batteries head to our battery blog
- We are also allowed to upsize our solar panels by 1/3rd of the inverter. 5kW inverter = 6.6kW of panel capacity
- We are limited to exporting back to the grid a maximum of 5kW per phase. When single phase systems are larger than the 5kW inverter (think 6kW, 8kW or sometimes double 5kW) we need to put in place export limitations which will be achieved by using smart monitoring. As a bonus you will not only get to see what your solar system produces but how much you use and what is returned to the grid.
As you can see the majority of these rules limit single phase properties while three phase properties have a better ability to have a larger system.
The most common single phase solar system size is 6.6kW but during 2022 we have started to see people show more interest in planning larger systems. This is due to their energy needs increasing due to continuing to work from home, planning for electric vehicles and being battery ready.
It’s good to note that if you are installing a system larger than the 6.6kW on a single phase property and aren’t planning on installing a battery your usage needs to be great enough to use the extra energy provided by your solar panels. Otherwise you have installed a system that’s not going to provide you with good value for money since there will be panel capacity going to waste.
We recommend households with an average daily use of:
0-25kWh select a 6.6kW system
25+ kWh select a 8kW + system
If you are a three phase property we believe bigger is better and recommend a 10kW inverter with 13.33kW (depending on roof capabilities) to maximise the energy potential from your property.
When planning future batteries it’s important to make sure your solar system is sized correctly so that there is enough energy to fully charge your batteries. If you have a single phase property but are high energy users with a suitable roof it may be beneficial to install two 5kW inverters.
In a two inverter system they both work together thanks to some smart monitoring but the standard inverter feeds the property and daytime consumption while the hybrid inverter charges the batteries via DC coupling. This allows us to fully use the 10kW inverter capacity set by Energex but also fit and fill batteries and cover household usage.
Give us a call to discuss your personal situation to find the right fit for your property and usage needs.