Solar Upgrades


Upgrading your existing solar

With years of experience installing thousands of solar panels McNae Energy and Solar is well qualified to advise on repairs and upgrades.
Here are some ways you can improve and extend your system.

Replace your existing inverter with a bigger one that can take more panels

If your system is more than five years old and your inverter is at the cheaper end of the price-quality spectrum or it is full-up to capacity, then it’s probably worth replacing it with a premium quality inverter and adding more panels at the same time. 

If you get an inverter with dual MPPT inputs, then you can put your old array on one input and use the second input for new higher efficiency panels. You could also consider a hybrid inverter so you can add batteries to give backup power.

Add more panels to your existing inverter

If you have an existing string inverter and there is spare capacity on the inverter, we can add more solar panels to maximise its output. We will need to source solar panels of similar electrical specifications and similar size and looks to your originals to preserve the aesthetics of your array and not compromise the electrical specifications of your inverter.

The good news is that it is possible—in fact, recommended—to oversize the solar input to your inverter.  To get the most annual generation we recommend adding at least one third more panel wattage than your inverter’s name plate rating. E.g., if you have a 3kW inverter, then for maximum annual output, you should install at least 4kW of panels.

You might be thinking; how can this produce more power if the inverter only has a 3kW output? Well, 4kW of panels will generally only produce 80 - 90% (3.2 - 3.6kW) of their rated peak power due to losses like panel soiling, wiring loss, panel degradation (about 0.5% each year) and shading. The inverter will safely limit its output at 3kW, but it only needs to do this for a few hours in the middle of bright summer days. For the rest of the year, in the mornings, evenings and winter the peak power will be way less than the rated 3kW of the inverter and you will get more generation in the mornings and afternoons due to the oversized array. In general, oversizing your inverter gives a huge annual gain in generation, but only minimal losses due to inverter clipping.

Add storage

If you are currently exporting a good chunk of your power, it may not be worth adding extra solar panels because you’ll just end up exporting more power.  But why not add storage?  You can add a smart diverter and use your hot water cylinder like a ‘battery’ or you can add lithium batteries. Either way, you’ll reduce your export and increase the self-consumption of your own generated power.

If your system is older, you may have to upgrade some of the electrical items in your set up.

McNae Energy and Solar are experts at upgrades. We know the best options and can guide you through to what is best for your particular system and patterns of use.

Install a new system alongside your original

We always recommend micro inverters for this option. Because each panel is fitted with its own micro inverter, this option allows lots of flexibility, can handle different orientations and improves performance in shaded situations compared to string inverters. Both your new system and the old system will happily co-exist together.


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We are happy to discuss our potential involvement in any project you may have.


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