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.
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.
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.