Solar Microinverters: When Is It Best to Use Them?
If you’re wondering what solar microinverters are, you’re not alone. As more homeowners prioritize renewable energy sources in their everyday lives, learning more about energy and electricity happens naturally. Most of us are somewhat familiar with solar panels, but understanding how they work and what components they use is another level.
Let’s take a deep dive into solar microinverters and how they contribute to a solar power system’s functionality.
What Is a Solar Microinverter?
Likely, all of the appliances you have in your home run on alternating current (AC) power, meaning the flow of electricity can reverse direction when needed. However, devices that run on batteries frequently use direct current (DC) electricity that remains steady.
The energy produced by solar modules creates DC power, which can be used for solar battery chargers without issue, but it won’t work to power your home. This scenario is where solar microinverters become necessary.
Inverter manufacturers have been around for decades, and inverter technology has improved dramatically over the years. One industry that has taken full advantage of this advancement is solar energy. Because solar microinverters are smaller than a home internet router, solar panel manufacturers can attach them directly to their panels, making them compatible for home use.
Advantages of Solar Microinverters
Attaching a microinverter to each solar panel may seem a bit excessive, but this setup allows for many advantages that over designs don’t afford.
Quick Shutdown
Solar microinverters can shut down rapidly, something that needs to be possible to protect firefighters and other first responders in an emergency. Without this quick shutdown capability, individuals could be exposed to deadly voltage levels from your solar panels.
Lifespan
As solar inverters have advanced, so has their reliability. Most manufacturers, such as Enphase microinverters, provide extended warranties on their solar microinverters, with most being valid for 25 years.
Versatility
Because solar microinverters are attached to each solar panel, they are ideal for solar arrays that create varying energy production levels. For instance, maybe some solar panels in the collection face east while others face southeast. Or perhaps some panels receive more shade during the day than others. Each microinverter can convert and regulate its solar panel’s output without compensating for all the energy going to a central inverter.
Panel-Level Monitoring
Utilizing solar microinverters also allows for solar panel monitoring at the panel level. Otherwise, most solar users only have the option to track production levels of their entire microinverter system. This advantage gives users the chance to make adjustments to individual panels when required.
System Expansion
If you’re considering starting small with your solar setup, it’s a good idea to use solar microinverters as they make it easy to expand your system down the line. Other inverters would make this change more complicated or possibly even impossible.
Disadvantages of Solar Microinverters
While they sound ideal, solar microinverters do have some downsides as well.
Extra Parts
If you decide to install 12 solar panels on your roof, that means you also need 12 solar microinverters. Having this additional hardware on your rooftop could pose a more significant fire hazard as microinverters are more likely to attract lightning. If your home or roof is made from a lot of wood or other flammable materials, you may not want to take the risk.
Maintenance
On top of their potential hazard, maintaining so many solar microinverters can be a hassle. Every time one of them has issues, you first have to determine which one it is and then have a solar installer climb up on the roof to fix or replace it.
Expense
For a standard, 5kW system for solar panels for home, solar microinverters will cost about $1,000 more than the standard alternative. For some people, this additional expense simply isn’t worth it.
What Is a Solar String Inverter?
If the disadvantages of solar microinverters are making you think twice, you still have the option of a standard string inverter system. A string inverter is a singular box that solar installers place near your home’s service panel and electricity meter.
String inverters work as a series circuit, meaning anywhere from 6 to 12 solar panels can be connected to the series at once. For most residential settings, one string inverter is enough to regulate the solar energy system’s output. String inverters can use power optimizers to help regulate voltage and compensate for solar panels’ production differences.
Advantages of String Inverters
Solar string inverters may not seem as hi-tech as solar microinverters, but they provide homeowners with some significant benefits.
Cost
Most string inverters will have a lower price tag than the amount needed to purchase enough solar microinverters. Plus, since most solar systems only need one string inverter, it is cheaper to have it installed into the system.
Simpler Setup
Again, a string inverter can easily hook up properly without wiring mishaps or connection issues because it’s a standalone box.
Easy to Troubleshoot
Since the string inverter is where all of the energy conversion happens, when your system has a problem, the first place you can check is the inverter, which is easier to access than solar microinverters would be. Having professionals make repairs will be cheaper and faster for this reason.
Disadvantages of String Inverters
Essentially, all of the advantages that solar microinverters offer directly combat the disadvantages of string inverters.
Partial Shade
If your solar panel installation requires some of your panels to experience shade for even a portion of the day, having a string inverter means every panel connected to that series will be affected. Also, if factors other than shade affect the output of an individual panel, the whole system will suffer.
Rapid Shutdown Compliance
Most string inverters do not meet the regulations for rapid shutdown on their own. If you live in an area where rapid shutdown compliance is required, solar installers will need to wire a rapid shutdown box to your inverter to make it compliant. While this may sound simple, it can create an additional expense you weren’t calculating.
Limits Expansion
Adding more solar panels to your system at some point in the future will likely mean needing to add another string inverter as well. This add-on signifies more wiring, possible reconfigurations, and of course, greater expense.
Monitoring
String inverters won’t identify when an individual solar panel is having issues as everything is connected and routed to the same place. Without the convenience of panel-level monitoring, you’re left guessing which panels may be defective, damaged, or covered in debris.
Lifespan
String inverters don’t last as long as solar microinverters. In fact, their lifespan averages between 8 and 12 years, less than half of solar microinverters. So while they may cost less upfront, over 25 years, you’ll have to double that expense.
Solar Microinverters vs. String Inverters: Which Is Best?
Every solar panel setup requires an inverter to convert the panels’ output into usable home energy. The best option depends on your situation and what the advantages and disadvantages of solar microinverters and string inverters mean to you.
Microinverters are ideal when you must comply with rapid shutdown requirements or have pockets of shade or differently-orientated panels on your roof. Plus, with the right upgrades, microinverters allow an owner to know when an individual panel has a problem. However, microinverters are more pricey and can create maintenance issues when they do need repairs.
On the other hand, string inverters are easy to set up, access, and maintain as everything is together in one place at ground level. If even one panel has issues, your string inverter will alert you to the problem right away (even if you don’t know exactly which panel it is). String inverters also cost up to $1,000 less than the average array of microinverters required in a solar home setup.
Unfortunately, string inverters won’t last even half as long as microinverters, so you should consider this in your solar budget. Also, string inverters aren’t great for solar designs that have varied panel orientations or shading issues. And, if you ever want to expand your system, a string inverter could create a roadblock that isn’t easy to get around.
Once you consider all of these factors, the choice of inverter for your solar panel system should be clear. Microinverters technology continues to advance at rapid speeds, while string inverters remain a reliable, convenient option.
Solar Is the Solution
Even though deciding on which inverter setup is best for your solar energy system may seem overwhelming, investing in this form of renewable energy will go a long way in making your home or business energy independent. Plus, as the solar industry continues to expand and improve, you will have all the support and professional advice you need from solar companies and solar installers.
Whether you go with a more traditional string inverter or choose to install solar microinverters instead, you’ll be happy with your systems’ ability to produce energy, save you money, and help make your property greener for years to come.
