Solar inverter warranties: What to know

If solar panels are the face of solar power, solar inverters are the heart behind it. Without inverters, you aren’t able to power your home with solar energy, so it’s vital that this important piece of the system is protected

As with solar panels, the available warranties and protections for solar inverters are among the most important factors to consider when comparing your options. However, sifting through pages of dense documentation can be intimidating and confusing, and warranties vary by both manufacturer and product, making direct apples-to-apples comparisons near impossible.

Fortunately, EnergySage has developed a scoring system to help consumers compare. This system considers factors such as product warranty terms, labor and shipping coverage, and how easy it is to transfer ownership.

We'll review the most important aspects of a solar inverter warranty, discuss what's standard for the industry, and compare some of the top inverter brands on the EnergySage Marketplace.

Inverters are the unsung heroes of solar energy systems. Without them, you wouldn’t be able to harness the power of your solar panels to power your home. Solar panels generate direct current (DC) electricity, but most home appliances require alternating current (AC) electricity. Inverters take the DC electricity from your solar panels and convert it to AC electricity usable for your home.

A solar panel system is a multi-decade investment that is paid off over years through reduced utility bills, and depending on your location, other benefits for sending excess power back into the grid. The less solar power your system produces, the more your home may need to draw from the utility company, which eats into your savings. A good warranty ensures your solar inverter is free from manufacturing defects over its term, protecting your expected return on investment.

We compared some of the top solar inverter companies' warranties against each other and the industry standard. Here’s what we found:

Solar inverter warranties look different from company to company and product to product, so we developed a scoring system for easier comparison. The warranty factors include:

Also known as a materials warranty, a solar inverter product warranty covers the integrity of the equipment itself. If your solar inverter has a defect or mechanical issue, if it breaks, or experiences unreasonable wear and tear, that's where your product warranty comes into play.

Unlike solar panel warranties, inverter product warranties are harder to compare apples-to-apples. For starters, there are three different types of inverters, all of which are subject to varying industry standards; most string inverter technologies come with a warranty of about 10-12 years, while microinverters and power optimizers often have 25-year warranties. If you install a string inverter with power optimizers, your string inverter and power optimizers will likely have different warranty terms. 

While the warranty terms for inverters themselves vary, warranties for communications equipment (which allow the inverter to connect to other devices like solar panels and battery systems) are typically capped at 5 years for both string inverters and microinverters.

With all this in mind, we created a ranking system that weighs inverter technology and warranty term length to better compare your options across different inverter technologies. However, the best inverter for you largely depends on your system’s unique needs: A 25-year microinverter warranty may rank higher than a 12-year string inverter warranty, but the string inverter may be better suited for your system and, therefore, more valuable to your investment.

While the warranty may cover replacement products or parts, that doesn't necessarily mean the manufacturer will cover the labor and shipping costs required to reinstall that equipment.

Your warranty likely won’t cover labor costs

Most manufacturers do not reimburse for the labor associated with replacements or repairs of their products. However, this usually isn’t an issue since many local installation companies will cover maintenance and repair costs within their own warranty agreement. 

Inverter companies with outstanding warranties may cover these costs entirely or up to a certain amount (i.e., all labor costs up to $500). Some inverter companies will pay for these costs by providing the company that performs the repair (i.e., your installer or another certified contractor in their network) a rebate or check rather than reimbursing you directly.

Likewise, shipping is usually on you

Many manufacturers will cover the material costs associated with the replacement part but not necessarily the fees to ship the equipment to your house. Or, they may be able to ship the product to a local or regional distributor, but require you or your installer to get that product to your home. As with labor fees, the best warranties may cover shipping but typically have an upper spending limit for what they will pay.

The top inverter manufacturers, such as Enphase, SolarEdge, and SMA, cover shipping costs for replacement equipment as part of their warranty agreement, so long as the "claim is justified," meaning they've confirmed it's a reasonable claim, and you followed the proper return merchandise authorization (RMA) process. You may have to pay a shipping tax under certain circumstances.

Most solar inverter manufacturers leave workmanship (labor) warranties to the installer. Still, like labor and shipping costs, some manufacturers offer an extra safeguard by tacking on their own workmanship warranty coverage. 

When applicable, it's typically only an option if you work with specific installers in a manufacturer's certified network. They're putting their brand name and reputation behind their work and want to make sure they can stand by the installer performing the installation.

Warranties exist to protect your purchase, but manufacturers also try to protect themselves from unreasonable claims. This is often known as the "fine print" – stated limitations and void clauses the manufacturer uses to protect itself. 

Here are a few limitations to keep an eye out for:

When you're comparing one solar inverter warranty to another, consider the following:

• How old is the company that is providing the warranty? Is it a bankable company, and does it have insurance policies or an escrow to ensure its warranties will be upheld even if it goes out of business? Bloomberg New Energy Finance (BNEF) publishes lists of top-performing solar inverter companies based on bankability.

• Who is on the hook to actually fulfill the warranty? Does the manufacturer have a parent company or subsidiary that backs the warranty or processes claims?

• How easy is it to make a warranty claim? Does the manufacturer allow you (the product owner) to submit the claim directly, or do you need to contact your installer? Does your installer need to come to your property and perform a diagnostic assessment before submitting any claims?

• What happens if you move? Does the warranty automatically transfer to the new system owner, or is it more complicated? Does the manufacturer charge a transfer fee?

Warranty transferability

Some companies offer extended product warranties at an additional cost to give you added peace of mind. Extended warranty offerings are more common with string inverters than microinverters, likely because the latter’s standard offering already spans two and a half decades.

The inverter you choose will ultimately depend on multiple factors, including its warranty. If you're still considering your options, you can easily compare quotes from local installers on the EnergySage Marketplace to go solar with confidence.