Solar Inverters: String Inverters, Microinverters, and Power Optimizers

Solar inverters play a crucial role in any solar energy system. They convert the direct current (DC) output generated by solar panels into alternating current (AC), which is used by most electrical devices and appliances. There are three main types of solar inverters: string inverters, microinverters, and power optimizers. In this post, we will discuss each type in detail, their advantages and disadvantages, and how to choose the right one for your solar energy system.

String Inverters

String inverters are the most common and widely used type of solar inverter. They are called “string inverters” because they connect multiple solar panels in a series, forming a “string.” The inverter then converts the combined DC output of the entire string into AC power.

Advantages of String Inverters

  • Cost-effective: String inverters are generally less expensive than microinverters and power optimizers, making them an attractive option for budget-conscious users.
  • Simplicity: With fewer components to install and maintain, string inverters are relatively simple and straightforward to use.
  • Proven technology: String inverters have been around for many years, and their technology is well-established and reliable.

Disadvantages of String Inverters

  • Shading issues: If one panel in a string is shaded or underperforming, the output of the entire string is affected, leading to reduced overall system performance.
  • Limited expandability: Adding more panels to a string inverter system can be challenging, as it requires a redesign of the entire string configuration.
  • Single point of failure: If the string inverter fails, the entire solar energy system goes offline.


Microinverters are small inverters that are installed on each solar panel individually. They convert the DC output of each panel into AC power, allowing each panel to operate independently of the others.

Advantages of Microinverters

  • Optimized performance: Each panel operates independently, so shading or underperformance of one panel does not affect the output of the entire system.
  • Expandability: Adding more panels to a microinverter system is simple, as each panel has its own inverter and operates independently.
  • Monitoring: Microinverters often come with monitoring software that provides detailed information about the performance of each panel, making it easier to identify and address issues.

Disadvantages of Microinverters

  • Higher cost: Microinverters are generally more expensive than string inverters, as each panel requires its own inverter.
  • Increased maintenance: With more components to manage, microinverters may require more maintenance than string inverters.

Power Optimizers

Power optimizers are a hybrid solution that combines some of the benefits of both string inverters and microinverters. They are installed on each solar panel and optimize the DC output of each panel before sending it to a central string inverter for conversion to AC power.

Advantages of Power Optimizers

  • Optimized performance: Like microinverters, power optimizers allow each panel to operate independently, minimizing the impact of shading or underperformance on overall system output.
  • Cost-effective: While power optimizers are more expensive than string inverters, they are generally less expensive than microinverters.
  • Monitoring: Power optimizers also provide detailed monitoring capabilities, similar to microinverters.

Disadvantages of Power Optimizers

  • Increased complexity: Power optimizers add an additional layer of complexity to the solar energy system, as they require both individual panel optimizers and a central string inverter.
  • Maintenance: Like microinverters, power optimizers may require more maintenance than string inverters due to the increased number of components.

Which One Should You Choose?

The choice between string inverters, microinverters, and power optimizers depends on your specific needs, budget, and solar energy system design. Consider the following factors when making your decision:

  • Budget: If cost is a primary concern, string inverters are generally the most affordable option.
  • Shading: If your solar panels are prone to shading or have varying levels of sunlight exposure, microinverters or power optimizers may be a better choice to optimize performance.
  • Expandability: If you plan to expand your solar energy system in the future, microinverters or power optimizers can make it easier to add more panels.

Consult with a solar energy professional to help you determine the best type of solar inverter for your specific needs and system design.