An Overview of Solar Inverters

Central vs Micro Inverters

Inverters are an essential component of home solar energy systems. They are used to convert the direct current (DC) electricity produced by solar panels into alternating current (AC) electricity, which is the type of electricity used in homes and businesses.

There are two main types of inverters used in home solar energy systems:

1. Central inverters are called “string” inverters because they are connected in series (or “strings”) with the solar panels, and they convert the DC electricity from all of the solar panels into AC electricity.
2. Microinverters: Microinverters are a newer type of inverter that are installed on each individual solar panel, rather than being connected in series with all of the panels. This means that each solar panel has its own inverter, which can be beneficial for systems with panels that are not all facing the same direction or are shaded at different times.

Inverters are typically located near the electrical panel in a home or business, and they are connected to the grid through a two-way meter. This allows the home or business to use the electricity generated by the solar panels, as well as sell excess electricity back to the grid. Inverters are an important component of home solar energy systems because they allow the solar panels to generate electricity that is compatible with the electrical system in the home or business. Without an inverter, the DC electricity produced by the solar panels would not be able to be used.

Solar Basics - What is a Solar Inverter?

Solar Power World
"Inverters are considered the brains of a solar project, whether it’s a 2-kW residential system or a 5-MW utility power plant."

Popular Makers & Models

Enphase (Microinverters):

Founded in 2006 and headquartered in California, Enphase Energy has become a global leader in microinverter systems. Enphase inverters are manufactured in the United States, Mexico, and China. One of the key features of Enphase inverters is their microinverter technology, where each solar panel is equipped with an individual microinverter, allowing for panel-level monitoring and optimization. This distributed architecture enhances system efficiency, improves resilience against shading, and offers flexibility in system design. Enphase holds numerous patents, including those related to its micro inverter technology, powerline communications, grid integration, and energy storage. Enphase has consistently gained market share in the United States and remains a preferred choice for residential solar installations.

Enphase's IQ-8 microinverters can provide "sunlight backup" by creating a microgrid, allowing the panels to continue powering the home in a grid outage without a battery installed.

SolarEdge (Central Inverters):

Established in 2006 in Israel, SolarEdge has made significant strides in the solar industry with its power optimizer-based inverters. SolarEdge inverters are manufactured in Israel, China, and the United States. SolarEdge was the first to successfully commercialize power optimizers, a device that offers module-level maximum power point tracking (MPPT), before feeding back the electricity generated into a central inverter. Their central inverters have a standard 12 year warranty, and typically fail after about 13 years. Most installers offering systems using SolarEdge include an extended, 25 year warranty. When your inverter eventually does fail, you will receive a brand new one. SolarEdge has a substantial patent portfolio covering power optimizers, inverters, and other advanced solar technologies. Their inverters feature rapid shutdown capabilities, module-level monitoring, and centralized arc fault detection for enhanced safety. SolarEdge's solution is often favored for commercial and larger residential installations due to its flexibility in system design, and compatibility with high-voltage batteries.

Sol-Ark (Central Inverters):

Sol-Ark is an American company that specializes in hybrid solar inverters, meaning that the system could be either grid-tied or off-grid.. Founded in 2014, Sol-Ark inverters are designed and manufactured in the United States. One of the standout features of Sol-Ark inverters is their all-in-one design, combining a solar inverter, battery charger, and transfer switch into a single unit. This integrated approach simplifies installation and enhances system efficiency. Sol-Ark offers a warranty of up to 10 years on their inverters. The warranty covers both the product and its energy output.. Sol-Ark's patented technologies include advanced MPPT (Maximum Power Point Tracking) algorithms, seamless grid-tied/off-grid functionality, and intelligent load management. These technologies optimize energy production, enable efficient battery charging, and provide users with control over their power usage. Sol-Ark inverters have gained popularity for their versatility, particularly in applications where grid independence and energy storage are essential. They pair well with HomeGrid batteries.

SMA (Central Inverters):

SMA is a German company that has been a prominent player in the solar industry since 1981. SMA inverters are manufactured in Germany and China. The company has a diverse range of inverters catering to residential, commercial, and utility-scale applications. SMA's installers are known for their reliability, high efficiency, and advanced grid management capabilities. SMA has been at the forefront of inverter technology, holding numerous patents related to string inverters, grid management, and energy storage integration. Their inverters incorporate features like integrated DC disconnect switches, reactive power control, and intelligent grid management to ensure stable grid integration and optimal performance.

SMA has traditionally held a significant market share in the United States, particularly in utility-scale solar installations. They lost market share to Enphase and SolarEdge starting in 2015 due to a lack of rapid shutdown capablilty and per panel monitoring ability. They have since caught up, while remaining the most cost competitive option.

AP Systems (MicroInverters):

Headquartered in the United States and established in 2010, AP Systems' microinverters are manufactured in China. AP Systems' microinverters feature advanced communication capabilities, enabling panel-level monitoring and optimization. Their patented technologies include advanced grid detection algorithms, enhanced MPPT, and rapid shutdown functionality. One microinverter can service four solar panels. AP Systems' micro inverters may be slightly less reliable than Enphase installers, but at a lower price point.

Generac (Central Inverters):

Generac, a well-known name in the power industry, has expanded its offerings to include solar inverters. Founded in 1959, Generac is based in the United States and manufactures its inverters domestically. Generac inverters are primarily designed for residential and commercial applications, providing grid-tied solar solutions. Generac offers a warranty of up to 10 years on their inverters, ensuring reliability and longevity. The warranty coverage includes both the product and its energy output, ensuring customer satisfaction. Generac's inverters have rapid shutdown capabilities, advanced monitoring, and compatibility with Generac's PWRcell battery storage system. These integrated solutions enable seamless backup power and optimization of solar energy usage.