Power optimizers: What you need to know

You'll need an inverter to convert your solar panels' direct current (DC) electricity into usable alternating current (AC) electricity for your appliances. There are multiple inverter options to consider when selecting solar equipment for your system. In this article, we'll discuss the ins and outs of power optimizers, a popular module-level power electronic (MLPE) often paired with string inverters.

Power optimizer systems offer a hybrid solution between a traditional string inverter and microinverters; with this technology, power optimizers are installed at each solar panel. As your solar panels produce electricity, the power optimizers "condition" the electricity from your solar panel, optimizing the voltage before sending it down to the inverter for conversion. Importantly, power optimizers are not an inverter on their own: they need to be paired with a centralized string inverter that handles the conversion process.

Because power optimizers operate at the panel site, they each act independently. As such, MLPEs like power optimizers are the best option for complicated installations or those that experience marginal shading. When you install a traditional string inverter without MLPEs, the panels can only produce electricity at the level of the lowest-performing panel on the same string. This isn't a problem when you pair the inverter with power optimizers. Because panels have their own MLPE component, solar panels will continue performing efficiently even if one panel in the system isn't producing electricity.

The overall size of your solar panel system and its expected energy output helps determine which size inverter to install with your optimizers. If your solar panels produce more electricity than the inverter can handle in a given moment, "clipping" can occur, resulting in power losses. To learn more about solar inverter sizing, check out our blog.

There are many reasons to consider installing a power optimizer system. For one, they allow for individual panel performance monitoring. Using power optimizers, you can compare how each panel performs independently rather than solely evaluating the system's performance alone. This can mean quicker equipment servicing, as it's easier to identify if a particular panel is failing.

Like other MLPE technologies, power optimizers are an excellent solution for more complicated installations with panels facing different directions or tilting at varying angles. If you have some panels facing east and others facing south, using power optimizers on each panel will allow them to perform to their maximum ability when sunlight hits them, as they will not be impacted by the production issues other panels in the system might experience.

Optimizer solutions are typically more expensive than traditional string inverters. However, the additional upfront cost can be worth the added monitoring and production benefits. If you have an easy installation on a single roof plane facing south with no shade, a lower-cost string inverter system can be an effective solution.

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

Efficiency

Just like solar panels, power optimizer systems have varying efficiencies. Efficiency is a measure of how much energy is lost in the form of heat during the conversion from DC to AC electricity. Higher efficiency inverters lead to higher overall system efficiencies and more solar electricity production.

Size

Power optimizers come in varying sizes, each designed to handle different voltages of electricity. Similarly, the inverters paired with power optimizers also come in varying sizes. Generally speaking, larger inverters will be more expensive; however, you don't want to install an inverter that's too small for your system or a power optimizer that's too small for the associated panel's energy output. Manufacturers of power optimizers often list guidelines as to the maximum DC wattage a solar panel should have when connected to their products. A qualified installer can also help determine which size centralized inverter is best for your system based on your proposed system design and site-specific conditions.

Warranty

Most power optimizer options available today come with a 25-year warranty to protect you against potential manufacturing defects. Additionally, the string inverter paired with power optimizers has its own warranty that typically lasts between 5 and 15 years. However, manufacturers that offer the same warranty term may provide different levels of coverage as part of the warranty. It's important to read and compare warranty agreements when choosing solar equipment.

Price

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

There are two primary manufacturers of power optimizers to be aware of:

SolarEdge

SolarEdge, headquartered in Israel, is the global market leader in power optimizer technologies. They make their one-string inverters to pair with their power optimizer solution. One of their more popular inverters is the HDWave. In addition to manufacturing power optimizers, the company partners with multiple solar panel manufacturers to offer smart modules. They also manufacture energy storage, monitoring, and EV chargers to pair with their inverter products. The company serves more than 45 countries worldwide.

Tigo

Though accounting for a smaller portion of the market, Tigo is another manufacturer that produces power optimizers. The company, founded in 2007, operates out of its California-based headquarters but serves Europe, Japan, Australia, China, and the Middle East.

Before going solar, evaluating multiple options is essential to ensure you're making the right decision for you and your property. On the EnergySage Solar Marketplace, you can receive up to seven solar quotes to compare online. Given your property and energy needs, local installers will provide custom quotes and propose an inverter solution. These quotes will include information about inverters, including but not limited to warranty, type of inverter, and manufacturer.