Got Solar? How to Retrofit and Expand Your PV System to Meet Your Needs

Michael Barnhard
Marketing Content Creator / Michael Barnhard

Let’s say you’ve owned a solar energy system for several years, and over time, your energy needs have expanded. Whether you need more power to charge a new electric vehicle or because of increased home consumption (maybe you invested in a new heat pump), there are many reasons why people may want to retrofit an existing solar energy system. Retrofitting is the industry term for upgrading or expanding an existing system, and it can mean adding new panels and Power Optimizers or even a new inverter to reach higher levels of energy generation. The simple answer is that you can add to an existing solar installation to make it more powerful, but there are some limiting factors and opportunities that you will want to consider.

What Can Your Inverter Support?

The first question you need to answer is about your inverter’s power rating. All inverters come with a maximum wattage that they can handle, which determines how many solar panels can be working on your roof at one time. A good inverter, like the ones from SolarEdge, will be built with an oversizing capability that allows you to add panels over and above the stated rating because the system’s peak energy output is only achieved for part of the day. For example, SolarEdge inverters generally come with 200% oversizing, so you can add panels up to that range beyond the inverter rating. If you have a solar system that does not support oversizing, you will have fewer panels installed, which means less power generation throughout the day. Swapping out an inverter is a relatively simple process, so consider adding one with oversizing if you want to get more power from your roof.


Can You Add Panels to Your Existing Solar System?

The next questions you’ll want to answer are how many panels would meet your needs, and if you have sufficient roof space for adding new panels. Panel technology evolves pretty frequently creating incremental improvements in energy output, so depending on your energy consumption, simply upgrading panels could be enough. You’ll probably also want to expand the size of your solar array, which could mean a mix of old and new panels. SolarEdge’s design flexibility allows users with SolarEdge Power Optimizers and inverters to use an array of panels that combine mixed wattages and orientations, which could give you more options than a traditional system. It means you could seamlessly use two different parts of your roof that face in different directions to expand your sun exposure. If you don’t have enough roof space, some suggest working with a roofer or other professionals to consider whether obstructions like vents can be moved or removed to create the necessary space. And, of course, you’ll also want to consider the orientation of your remaining roof space to the sun to get a sense of how well any expansion might perform relative to your needs.

If you are adding solar panels, this is a great opportunity to add Power Optimizers to your panels and upgrade to a SolarEdge system. There are a few reasons why you want Power Optimizers. The first is that they allow solar arrays to work together even if they’re set up in different orientations. The second is that Power Optimizers, as their name implies, are designed to enable each panel to perform at its maximum potential. A system without optimizers only produces energy at the level of the weakest panel on the string, so whether panel aging, dust, shading or other factors have reduced your power generation over time, Power Optimizers can improve the performance of your entire system. Lastly, they enable panel-level monitoring, which means that you and your installer can see how each panel is performing, enabling remote diagnostics and faster resolution of potential issues.

The Path Forward

While there is a lot to consider when expanding an existing solar energy system, an installer can help you work through the key issues and provide options about how to add on to what you already have. The best place to start is to think through how much energy your upgraded system will need to produce, and then work through your options to reach your goal. Solar technology is constantly evolving, so new add-ons and efficiencies are frequently being released. Thus, even if it looks like you can’t quite get there today, don’t be discouraged and keep checking in for the latest updates.

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