If you want to maximize your solar energy system’s production, finding the best solar inverter is as important as the solar panels you choose. For an “uncomplicated” roof – one that faces south and has no gables, chimneys, or other obstructions that can cast a shadow – the best solar inverter for you may be a standard string (aka central) inverter. But, more than half of new residential solar installations are using module-level power electronics (MLPEs) – such as power optimizers and microinverters – to maximize electricity production on more complicated, less ideal rooftops.
In the world of MLPEs, you might be trying to decide between two big names, SolarEdge vs. Enphase, and with good reason: about 95 percent of quotes on EnergySage included either SolarEdge or Enphase in 2022! That said, there are many other great inverter options to consider. At the end of the day, the question of which is the best solar inverter comes down to performance, warranties, cost, and personal preference.
There are three main types of inverters: string inverters, optimized string inverters, and microinverters.
The best inverter for you will depend on factors like their performance, warranty, and cost, as well as your own unique setup.
Some of the best available inverters come from Enphase, SolarEdge, SMA, and Tigo.
Visit the EnergySage Marketplace to receive custom quotes from local solar installers.
When it comes to inverters there are three broad categories: string (aka central) inverters, optimized string inverters, and microinverters. Here’s a breakdown of how they compare:
String inverters provide centralized power conversion and collective monitoring for all solar panels connected to that string. The power output is typically not optimized at the panel level, though there are some integrated software technologies that can improve performance. If you’re looking to increase your system’s size, you might need to add an additional string inverter to do so – overall, the maximum output power or the “size” of the inverter is typically close to the size of your solar energy system. String inverters are very efficient and might be right for you if you have an uncomplicated roof with lots of sun!
Optimized string inverters
Optimized string inverters also provide centralized power conversion and offer monitoring at the string level. However, because this technology pairs with panel-level power optimizers, they also provide panel level monitoring and optimization. If you want to increase the size of your system with optimized string inverters, you may need to add another string inverter, making the add-on more complicated. The maximum output power of the inverter should be close to the size of your solar energy system.
Microinverters provide power conversion and monitoring at the solar panel level. In a solar energy system with microinverters, the output power of each solar panel is converted independently. If you’re thinking you might want to increase the size of your system in the future, microinverters are a great option. You’ll want the maximum output power of your microinverters to be close to the wattage of the solar panels in your system.
When choosing which inverters to install in your solar energy system, there are a number of factors to consider. Ultimately, your decision will likely depend on your own unique situation (like the setup of your roof), but if you’re between a few different options, it’s good to have an understanding of how they stack up against each other.
The output power of your inverter provides a sense of its size. For microinverters, you’ll want the maximum output power to be about the size of your solar panels (typically 300+ Watts) to avoid clipping, which occurs when your solar panels are producing more power than your inverters can handle at a given point in time.
On the other hand, if you have a system with a string inverter, you’ll want your inverter’s maximum output power to be close to the size of your solar panel system (typically about 5-10 kilowatts, kW). If you have multiple string inverters in your system, you’ll need to make sure the output power of each inverter roughly matches the total wattage of its string of solar panels.
The efficiency of your solar inverter, expressed as a percentage, indicates how well it converts the direct current (DC) electricity that’s generated by your solar panels into alternating current (AC) electricity, which is the type of electricity you need to power home appliances. When your inverter converts electricity from DC to AC, some energy is lost in the form of heat – the higher the losses, the lower the efficiency. The higher your inverter’s efficiency, the better (most are somewhere between 96 and 99 percent efficient).
There are multiple voltage indicators that are important to an inverter’s overall performance. The minimum and maximum voltages, expressed in DC, provide a voltage level range at which your system can input solar energy from your panels to your inverter – the wider the range, the better your inverter can perform in more extreme conditions. You can calculate your inverter’s voltage performance using the following calculation:
(maximum voltage - minimum voltage) / maximum voltage
If you have an optimized string inverter system, be sure to include the voltage range associated with the power optimizer. Generally, your voltage performance will range between 0.4 and 0.8, with higher numbers indicating better performance.
Nominal voltage is another metric you might see for your inverter. It’s fairly standardized for all home solar energy systems and represents the voltage level at which your inverter connects to your home’s electric system (expressed in AC) – most inverters for home solar systems will connect at either 208 or 240 VAC.
If you’re noticing any unusual issues with your solar panel system, chances are it’s the inverter. While solar panel systems are highly reliable, inverters are the most likely component to fail. So, you want to make sure that your inverter has a comprehensive warranty in case anything goes wrong.
MLPEs like microinverters or power optimizers often come with a 25-year warranty, like the solar panels they live behind. On the other hand, most string inverters come with a warranty of around 10 years. It’s also important to consider other warranty factors like labor coverage and company bankability (i.e., how likely they will be around to actually uphold your warranty). Learn more about inverter warranties.
Typically, string inverters are more affordable than microinverters – and they’re even cheaper if you don’t include power optimizers. This is because you’ll only need one (or a couple) of inverters per solar energy system as opposed to one for each solar panel, cutting down on both material and labor costs.
Want to learn about the best inverters on the market? Here are some of the top companies to explore:
Type Of Inverter
|0.24 - 0.366 kW
|97 - 97.5%
|0.12 - 0.57
|Optimized string inverter
|3.0 - 11.4 kW
|97.5 - 99%
|0.23 - 0.80
|3.0 - 11.4 kW
|96.8 - 98.5%
|0.79 - 0.83
|Optimized string inverter
|7.6 - 11.4 kW
|98.4 - 98.5%
*Extended warranty available at additional cost
Best for: warranty duration
Enphase is headquartered in California and manufactures the most popular microinverter product in the United States (and the most popular inverter on EnergySage). Systems with microinverters generally cost more so you should expect a higher price tag if you choose to go with Enphase inverters. Enphase also offers a storage product that can be used in conjunction with its microinverters: the IQ Battery.
Enphase’s microinverters come with the longest base warranty at 25 years. Learn more about Enphase’s inverter warranty.
Best for: efficiency
SolarEdge Technologies is headquartered in Israel and manufactures the leading power optimizer product across the globe. They also manufacture hybrid inverters that are compatible with energy storage solutions, like their Energy Bank.
The SolarEdge HD Wave inverter series is the most efficient of the inverters on our list at 99 percent efficiency. Their power optimizers come with a 25-year warranty and their string inverters have a 12-year base warranty (but can be extended at a cost). Learn more about SolarEdge’s inverter warranty.
Best for: cost
SMA America is a subsidiary of SMA Solar Technology, which is headquartered in Germany and manufactures string inverters. The company was founded in 1981 and is widely considered to be a manufacturer of high-quality inverter products. SMA has long held a strong position in the US commercial solar sector, though historically the pricing of their residential products stood in the way of gaining ground in residential solar. However, SMA’s newer products and pricing are very competitive: many consumers on EnergySage receive lower cost quotes with SMA inverters than other options, when paired with similar solar panels.
SMA’s string inverters come with a standard string inverter warranty of 10 years, which can be extended at additional cost. Learn more about SMA’s inverter warranty.
Best for: voltage performance
Tigo Energy is a manufacturer of inverters, power optimizers, and rapid-shutdown devices based in the United States. They may not be a household name like SolarEdge, but their optimized EI inverters have the best voltage performance of any of the companies on our list due to their high maximum and low minimum voltages. Tigo’s inverters are hybrid and pair well with their EI Battery storage solution.
Tigo offers one of the longest base warranties for string inverters at 12.8 years (and a standard 25-year warranty for their power optimizers). Learn more about Tigo’s inverter warranty.
Ultimately, your inverter decision will be based on a number of factors, including the complexity and shading of your roof, the likelihood you’ll want to expand your system in the future, and more! To better understand what solution is best for you, check out some of our other inverter resources:
The best way to determine which inverter option fits your needs is to review actual quotes from qualified local installers in your area. When you register your property for free on the EnergySage Marketplace, you can review multiple that have been customized to your home and evaluate the costs and benefits of different inverter options! If you have any questions about your quotes or the equipment, be sure to schedule a call with one of our Energy Advisors, who can help guide you through your decision.