Have you ever been told that you can’t install a residential solar system larger than 6.6kW? Well, here’s some good news – that’s not true. While 6.6kW systems are common, that is certainly not the limit!
So, why do people believe there’s a limit? It’s partly due to solar “professionals” lack of understanding, but more troublingly, some less-than-honest salespeople perpetuate this myth to simplify their job. Installing a standard 6.6kW system is straightforward, after all, meaning companies can sell more solar, with less work.
Should You Settle for 6.6kW?
While a 6.6kW solar system may cover a portion of your energy needs and is the most prevalent residential system size, it might not be the ideal fit for everyone. If you have a large family or a home filled with power-hungry appliances, you might want a system that more significantly reduces your energy bills.
Is 6.6kW the Limit?
No, residential solar systems can go much larger than 6.6kW. However, whether you should or not depends on two crucial factors:
1. Is It Worth It?
The primary goal of residential solar isn’t just to generate power but to consume it yourself. Feeding excess electricity back into the grid can be very cost effective, but that depends on where you live and the prices in most places are low. These days, the focus is on self-consumption, where you use what you generate instead of selling it back to the grid. If you use a lot of energy having a larger system that compensates for that makes a lot of sense.
If you have a tiny bill (less than $100 a month) then going over 6.6kw is less worthwhile.
2. Can You Export It?
Keep in mind that export limits exist to prevent excessive solar energy from flooding the grid. Even if you generate surplus power, you may not be able to sell it all back to the grid. In most cases you can export at least 5kw per phase which is still plenty.
How Big Can You Go?
The answer varies depending on your location and your retail provider’s export limitations.
For the purposes of this blog we are going to talk about the largest installation Proven Energy has ever installed on a residential house.
In Queensland, the maximum size solar system that can be installed on a single-phase electricity connection is a 10kW inverter, with 13.3kW of panels. This means that you can install up to 13.3kW of solar panels, but your inverter will only be able to export 10kW of power to the grid at a time. Recent changes in 2023 mean you can also have up to 10kw of ac-coupled Battery Inverter capacity.
In Queensland, there is a limit of 5kW per phase on the amount of solar power that can be exported to the grid at a time, regardless of the size of your system. This means that if you have a system larger than 5kW, you will need to use some of the solar power that you generate directly in your home, store it in a battery, or just be ok with the system sometimes just powering back as it needs to.
The maximum size solar system that can be installed on a three-phase electricity connection in Queensland varies depending on your location and the capacity of your switchboard. However, it is typically possible to install a system of up to 30kW of inverter (s) plus 40kw of panels.
BIG Systems
At Proven Energy we have installed many 30kw inverter with 40kw panel systems. Generally we install these on farm sheds, workshops, and businesses but also on quite a few homes. Generally these are installed on the shed or a combination of shed and house roof at the home.
If you have a commercial size solar system on a commercial premises, the math makes sense without even trying. If you’re using lots of power during the day, then a 40kw system is ideal.
We have also installed plenty of these on homes. Generally some on the house and some on a large shed. Even with this system being well oversized for these house the payback is still much better than compared to interest rates (yes, even in 2023). So if you have $30 -$40k burning a hole in your pocket, put it to better use than and see it turn into a solid investment.