What is a string inverter? String inverters are a type of solar inverter that transform direct current (DC) into alternating current (AC). This makes them an ideal choice for residential and small-scale commercial solar systems. If you’re considering installing a solar system, it’s important to understand the different types of inverters available and what each one can offer. In this post, we’ll take a closer look at string inverters and explain why they might be the best option for your home or business.
String inverters vary in capacity, but most can typically manage multiple strings of panels. For example, you may be able to have four groupings of four panels each for a total of sixteen on one string. The size (measured in kilowatts or kW) and the wattage determine how many solar panels you’re able to safely attach without wasting energy.
String inverters are optimal for rooftops that have an entire south-facing side without any shading blocking the sun. If even a single panel becomes shaded, it would then limit energy production for the entire string based on the worst-performing panel’s output. This is why microinverters are recommended for rooftops with a lot of shading.
The benefits of string inverter systems
String inverters have advantages that make them stand out against other types of inverter systems. Some notable advantages are listed below:
Cost
String inverters are more affordable than other types of solar inverters because manufacturers have had time to make their production processes more efficient. You also only need one string inverter for most solar installations, as opposed to microinverters and DC power optimizers which are used for each solar panel.
While solar panel arrays have a lifespan of 25 years, string inverters will only last 8 to 12 before needing replacement. Consequently, over time, this will add more cost to your solar energy system. [1]https://thosesolarguys.com/how-long-do-solar-inverters-last/
Replacement is simple
For most home installations, you will only need one string inverter. With fewer parts, troubleshooting problems becomes more comfortable. Over the life of your system, your inverter is likely to be the first piece of equipment to fail. Solar panels are expensive, and the thought of having to troubleshoot or replace many inverters or power optimizers is daunting. However, being able to switch out one unit at an affordable price is more appealing.
Disadvantages of string inverters
Different types of inverters have different benefits and drawbacks, so picking the right one will depend on what your specific needs are.
Incompatible with system expansion
String inverters need to properly correspond in size to the solar array as a whole. If you’re planning on eventually enlarging your photovoltaic system, string inverters may not be ideal for you. If you want to get the best solar panel output, the inverter needs to be near its maximum capacity. If you add more panels, the inverter would need to be larger than your current one.
Although it may be costly, you could wire your new panels to a different inverter that’s thereby connected to the loads from your other inverter.
If you think you might want to expand your solar system in the future, microinverters are a better choice. They convert DC to AC behind every panel, so they can be easily expanded. You can add as many panels as you want, and your system will still work properly.
Limited system monitoring
In our smartphone age, being able to monitor the output of your solar installation can be a nice perk. With a string inverter, you don’t get as much system monitoring capability as you do with other types of inverters. This makes it difficult to detect any potential issues that may be present in your solar panel array or system components.
Microinverters and power optimizers come equipped with sophisticated monitoring capabilities that allow you to identify what part of your system is performing the best or worst and what needs to be adjusted. This gives you a better idea of what’s happening with your solar energy system overall.
Shorter lifespan
String inverters typically have a shorter lifespan than other types of inverters, ranging from eight to twelve years. This means that you’ll likely have to replace your string inverter at some point during the 25-year lifespan of the solar panel array. Replacing the entire system can be costly, so it’s important to consider what type of inverter will work best for your needs in the long run.
Although string inverter replacement costs are typically modeled into your solar savings estimates, it can still feel like you’re essentially buying a car with an 8-year warranty knowing the engine might die in half that time.
If you’re hoping to save money in the long term and increase your peace of mind, choose microinverters with 25-year warranties. They’ll last as long as your solar system does. [2]https://news.energysage.com/enphase-warranty-review/
Bottom Line
String inverters are less expensive than other solar options, but they only work well if your roof is unobstructed. If you have any type of obstruction, such as trees blocking parts of your roof during certain times of the day, you will not get optimal production. If even one panel gets shaded, the rest of your array might as well be shaded too.
You’ve probably heard the saying “a chain is only as strong as its weakest link.” Well, this can be compared to stand-alone string inverters.
If you want to increase the power your photovoltaic panels produce, we recommend using microinverters or DC power optimizers. This is especially effective if you have a roof that faces different directions or if your panels are in partially shaded conditions. Enphase is a top manufacturer of microinverters, and SolarEdge specializes in power optimizers.
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