Microinverters: What you need to know

Unleashing the power of your solar panels requires more than just sunlight. Inverters are essential components of every solar panel system. Think of it like this: Solar panels capture energy from sunlight. Inverters harness that energy to create electricity compatible with your home.

More specifically, inverters convert the direct current (DC) electricity your solar panels generate into alternating current (AC) electricity that your home appliances can use. These unsung heroes of solar panel systems come in all shapes and sizes and contribute to the overall efficiency of your system.

While traditional string inverters connect multiple panels to a single inverter, microinverters operate at the individual panel level. They can optimize the conversion process to boost your solar panel system’s efficiency. Let’s dive deeper into microinverters, their technology, and how they compare to other inverters.

Microinverters convert the electricity from your solar panels into usable electricity. Unlike centralized string inverters, which are typically responsible for an entire solar panel system, microinverters are installed at the individual solar panel site. Most solar panel systems with microinverters include one microinverter on every panel, but it’s not uncommon for one microinverter to connect to a handful of panels. 

Microinverters are classified as module-level power electronics (MLPE). Each microinverter operates at the panel site independently of the other inverters in the system. The individual nature of microinverters is advantageous for complicated installations or those with shading. Due to its centralization, traditional string inverter technology operates at the level of the lowest-performing panel. With microinverters, solar panels have their own inverters and will continue performing efficiently even if one panel isn't producing as much electricity as the others.

Microinverters create flexible solutions for many solar installations, but they might not fit everyone’s unique needs.

Top pros and cons of microinverters

Pros of microinverters

Microinverters are an excellent investment for most solar shoppers, especially if you have a complex roof or one with partial shading. Microinverters operate at the panel level and don't require power optimizers for rapid shutdown compliance and optimization. If something is wrong with one microinverter, only the panel attached to it will shut down instead of the entire system. Diagnosing and fixing issues with microinverters is often quicker than with central string inverters. 

Microinverters can easily grow with your solar panel system over the years. Let’s say your energy demands increase in the future. You can add more panels with microinverters instead of matching the power output of a central inverter with your new system size. Plus, most microinverters are warranted the same amount of time as the panels they're attached to (typically 25 years), so you can expect them to last longer.

Cons of microinverters

Microinverters are generally more expensive than string inverters. While you'll likely have better overall system performance with microinverters, it’s important to ensure that the long-term performance benefit outweighs the upfront cost. Microinverters are also located on your roof, making maintenance more difficult (and costly if your warranty doesn’t cover labor). Alternatively, string inverters typically sit more conveniently on the side of your house. 

Clipping refers to power losses associated with microinverters and is an important consideration when shopping for a solar panel system. Often, the power output rating of your microinverter is lower than that of the panel itself. If your solar panel produces more electricity than its microinverter can convert at a given moment, clipping occurs, and your system can’t take advantage of the full power output of your solar panel.

Many homeowners choose microinverters. They're by far the most popular option on EnergySage. In part, this is due to their improved performance. Some installers also prefer them, meaning they include them in quotes more frequently. 

Microinverters are a great choice if your roof has multiple planes facing different directions. They also make sense if your roof experiences shading throughout the day or has different angles to it. Let’s say you have some panels facing east and others facing south. In this case, microinverters optimize performance by isolating each panel's production issues.

However, if you have a single roof plane that's south-facing without shade, we recommend talking to our installer about different options. In this case, microinverters probably aren't worth the extra cost.

Three common inverter options are microinverters, string inverters, and power optimizers. Here's how microinverters compare:

String inverters vs. microinverters

Wiring is the biggest difference between string and microinverters. Depending on the size of your solar panel system, you only need to use one or two string inverters to wire your panels. Microinverters often connect to just one panel. 

Given the minimal wiring requirements, string inverters are cheaper to install and maintain than microinverters. That said, the simplified wiring scheme can also make it more expensive to expand your solar system in the future. It also means that underperforming solar panels will affect the whole circuit rather than just its own output.

Power optimizers vs. microinverters

Unlike micro and string inverters, power optimizers don't immediately convert direct currents to alternate currents. Instead, they "condition" it and send it to a centralized inverter. These module-level power electronics (MLPEs) are similar to microinverters because they can monitor individual solar panel performance and allow flexibility when building a solar system.

When comparing your microinverter options, there are a few main factors to keep in mind:

Efficiency

Just like solar panels, microinverters have varying efficiencies. An inverter's efficiency measures energy losses during the conversion from DC to AC electricity. The more efficient the microinverter, the more solar electricity production.

Efficiency ratings are often measured under ideal conditions, but things like climate and weather contribute to a microinverter’s actual efficiency. Weighted efficiency ratings can help you level your expectations of a microinverter's performance. For example, the California Energy Commission (CEC) efficiency is a weighted efficiency rating based on conditions similar to the U.S. Southwest. 

Size

Microinverters come in various sizes, each designed to handle different voltages of electricity. You want to install a microinverter that's a manageable size for the associated panel's energy output and avoid excessive clipping. 

You’ll probably hear the terms “single-phase” and “three-phase” as you explore your microinverter options. This refers to how power is distributed in a microinverter; electricity flows through one active wire in a single-phase system and three active wires in a three-phase system. Single-phase microinverters are typically less expensive and suitable for many home solar panel systems, but three-phase microinverters transmit more power and can boost performance. A three-phase microinverter may be worth it for bigger homes with greater energy demands.  

Microinverters allow solar panels to produce electricity independently but can accommodate multiple panels in some cases. The benefit of two-in-one or four-in-one microinverters is cost, as you require fewer microinverters for your installation.

Warranty

Most microinverter options available today come with a 25-year warranty, protecting you against potential manufacturing defects or undue degradation. Albeit tedious, it's essential to read and compare warranty agreements when choosing solar equipment. Different microinverter manufacturers may offer the same warranty term but provide different levels of coverage as part of the warranty. 

Price

Although they are not typically the most expensive component of a solar panel installation, it's still important to weigh the price you'll pay for microinverters. Higher efficiency microinverters with longer warranties often come with higher price tags but can be worth it depending on your solar panel system setup and preferences.

Rapid shutdown requirements

When a rapid shutdown occurs, microinverters can shut down automatically in compliance. Each module has software to shut down in sync with these rapid shutdowns, so no extra hardware is needed.

Monitoring

Most microinverters today include smart monitoring systems to give real-time updates on your system’s performance and manage your appliances. Some companies have apps to deliver this data, while others can be viewed on any web-connected device.

Though Enphase currently dominates the U.S. microinverter market, other options do exist. Here are some microinverter companies you should know:

Enphase

Enphase is the market leader in microinverter technologies. Notably, the IQ8 series is hailed as the “all-in-one Enphase Energy System” due to its ability to form a microgrid during an outage. Enphase microinverters use smart technology to monitor performance through their app.

Hoymiles

Hoymiles offers microinverters to accommodate one, two, or four solar panels, depending on the complexity of your roof. Hoymiles microinverters are efficient and use smart technology to monitor performance.

APsystems

APsystems offers single-phase and three-phase microinverters. The Energy Monitoring and Analysis (EMA) software monitors performance and communicates in real-time. APsystems prides itself on being an affordable and flexible microinverter solution.