During periods of lower solar energy production, such as winter and cloudy days, it is frustrating to see power bills rise. With an oversized PV system installed, you’ll be able to produce more energy than usual during these periods, which can save you money and maximise electricity production!
What does PV Oversizing Mean?
In Australia, it’s common to install a solar system with the solar array operating at the same capacity as the inverter. PV Oversizing your system means that your solar panels are installed with a larger capacity than the inverter is meant to operate at.
Many electricity providers limit the export of energy from homes to the grid at 5kW. A 5kW inverter is Australia’s most popular size due to this cap. Most people would match 5kW worth of panels to a 5kW inverter as that would be more compatible right?
It seems strange to install a lower capacity inverter and lose all the extra electricity produced. But is it actually lost? Oversizing your system is a great idea once know the truth about panel efficiency!
Reality of Your Solar Panel Efficiency
A single solar panel will essentially never produce the amount of power that they are set to. For example, if you have a 330W panel, it will seldom generate 330W of power at a time.
The reason why it is rated higher than it usually generates is due to the Standard Test Conditions. The panels have been tested in conditions set for optimal energy output. These perfect conditions are not based on reality (even at midday, when the sun is the strongest) and do not consider any elements that could alter the panels performance, such as overcast days, shading, colder months, etc. This is why 5kW of panels will most likely never reach 5kW of electricity production.
Adding an extra panel and oversizing the system can assist your inverter to operate at an above average efficiency, making up for any power lost!
Benefits of Oversizing your PV System
PV Oversizing your panels will save to quite a bit of money and allow for increased electricity production. Some locations in Australia have imposed limits on the size of inverter you can install to 5kW. By oversizing your panels up to 6.6kW, your 5kW inverter can work at a greater efficiency and generate higher levels of electricity for your household.
PV Oversizing also works the same way with weather and sun conditions. During the day, there is a window of around 6 hours of optimal sunlight conditions where most of your energy is produced. By oversizing you can take full advantage of the sunny hours and generate more energy than you would with a smaller panel array. Plus, when the environmental conditions are not favourable, the system will still be able to produce more energy for your consumption.
PV Oversizing is also completely safe and effective! The latest inverters generally function at constant and efficient levels. When the panels installed are only supplying three quarters of the inverter’s capacity, you get a less efficient inverter.
If you are interested in generating more energy and saving some money, oversizing your panels is a great option for you!
2 Responses
Good one.
Sounds like a smart move.
Is there an upper limit to the solar panel capacity?
You quote 6.6 with a 5kW inverter. Would it be possible to run a 10.5kW panel array with a 5kW hybrid inverter?
I have a 4.2 KW system . 16 Jinko 300w panels.
Solax inverter 4.2kw.
I would like to add a couple more panels to boost its capacity to 5kw.
How much would this cost .