SMA vs Fronius String Inverters: What’s Best?

SMA America and Fronius are industry leaders in solar string inverter technology. Both companies offer high-efficiency inverter solutions for residential, commercial and hybrid solar energy systems at an affordable price point. In addition, both inverter manufacturers provide unique technologies born from their decades of research and development across various energy production and storage applications.

Inverters are an important component of your solar energy system; they are responsible for converting the energy generated from your solar energy system into usable power to energize your home. If the installation site has environmental barriers to energy generation such as shading, a north facing roof, low sunlight hours, etc., optimizing solutions such as microinverters and inverters with optimizers may be recommended. The right inverter for your system is cruical, so it's important to learn what makes the "best solar inverters".

Many homeowners and installers want to know, “Which string inverters are better, SMA or Fronius? ” So, we went ahead and looked at string inverter series lines, option and accessories from both manufacturers. We found that both companies build powerful inverter technology for use in a wide variety of system types. but both companies produce slightly different products. It is our opinion that both invverter lines make an intelligent investment choice for a home or commercial solar power system. We believe both manufacturers deliver exceptional quality and are great choices. Let’s look now and see what’s best.

SMA and Fronius offer high-efficiency string inverters that should be considered by any prospective DIY or professional installer. We highly recommend both companies and their respective technologies and have compared their various offerings your consideration.

In this SMA vs Fronius inverter comparison, we will be taking a closer look at the following:

• Lines, Technologies & Price Points
  • SMA SunnyBoy vs Fronius Primo
  • SMA SunnyBoy Storage vs Fronius Symo Hybrid
  • SMA Tripower Core-1 vs Fronius Symo (Advanced and Lite)

• Warranty Comparison

• Solaris Recommendations

Interested in SMA or Fronius? See our inverters here.

SMA & Fronius Lines, Technologies & Price Points

SMA and Fronius serve both residential and commercial solar systems, in addition both manufacturers offer single phase, three phase and hybrid inverter options – which means their inverters are specifically designed for grid-tied and hybrid solar energy systems. To gain a better understanding of the various options, we will be comparing the following:

• Residential - Single Phase Inverters
  • SMA SunnyBoy 
  • Fronius Primo
• Commercial - Three Phase Inverters
  • SMA Tripower Core-1
  • Fronius Symo Advanced & Lite
• Single Phase - Hybrid (On-Grid w/ Battery Backup)
  • SMA SunnyBoy Storage
  • Fronius AC/DC Coupled Options

Which option will work best for your specific installation depends primarily on your site and energy goals. Do you plan for battery backup at a later date? If so, you would be better off starting with a hybrid inverter so you can add battery backup in the future. If a single phase inverter is selected, the inverter would need to be changed out to add battery backup or an expanded solar array can be added to go to an additional inverter. For further savings it is best to plan your inverter for the future. To find out more about your options with SMA and Fronius, check out our comparisons below.

SMA SunnyBoy vs Fronius Primo

SMA’s single phase inverter line, the SunnyBoy, offers a range of wattage options that allow for hundreds of string configurations and multiple independent MPPTs. This means that your solar energy system can be designed specifically to your usage, which leads to greater cost savings with less materials. All SMA inverters come equipped with integrated solar system monitoring solutions through their free online platform which can report data both to you and your installer (if applicable).

The -41 iteration of the SMA SunnyBoy pairs with their Smart Modules which include options such as optimizers, fire safety, rapid shutdown as well as monitoring. Unlike traditional string and optimizer systems which require optimizers on each individual panel, SMA inverters can run without the addition of optimizers for every panel in your array. If only part of your energy system is affected by shading optimizers can be installed at that portion of the system while the lower cost rapid shutdown Smart Modules cover the rest of the system for rapid shutdown compliance. This can add a great deal of value to the solar energy system without dramatically increasing materials costs.

Fronius offers the single phase inverter line - Primo, is compact with a sleek and lightweight design that is easy to both place and install in residential applications. The inverters come with a number of integrated features including: dual power-point trackers, high system voltage, wide input voltage range and integrated monitoring options.

Unlike SMA, Fronius does not offer an optimizing solution, however, it is important to note that single phase systems are typically used on installation sites that do not require such solutions. Integrated monitoring allows users to quickly identify faults or energy loss in the system. Fronius overs the same coverage solutions as SMA with their online platform and app. In terms of monitoring both manufactures deliver expansive details so you know how your solar energy system is performing.

	SMA Sunny Boy	Fronius Primo
Size Range:	3kW - 7.7kW	3.8kW - 15kW
Average Efficiency:	97.33%	95.95%
Average Cost per Watt*:	$0.24	$0.32
Warranty Period:	10 Years	10 Years
Downloads:	SunnyBoy Specs SMA Warranty	Fronius Primo Specs Fronius Warranty

*Averages based on pricing as of the posting of this article.

Winner: SMA

While Fronius has a wider offer of size ranges, SMA has a higher average efficiency rating and lower price point. Though, it may be worth comparing prices if multiple inverters are required under SMA, there may be a single inverter option with Fronius. In terms of warranty periods, the two manufacturers are tied.

SMA Tripower Core-1 vs Fronius Symo (Advanced and Lite)

SMA's Tripower Core-1 three phase commercial inverters come fully integrated with SMA's Smart Monitoring solutions and provide reliable, flexible and safe inverter solutions fit for almost any commercial application. The free standing design of the Tripower inverters fit for commercial roof tops, car ports, ground mounts and more. No additional racking is needed to install the inverters, which means less bill of materials and time spent installing the system.

The inverters come with six MPP trackers and twelve direct string inputs - making it one of the most flexible and cost effective commercial solar inverter solutions on the market. Equipped with rapid shut down capabilities and enhanced DC AFCI arc-fault protection the inverters are fully compliant with the newest safety standards.

Fronius offers two three phase commercial inverter options with through their Symo line with the Symo Lite and Symo Advanced inverters. The Symo Lite line is transformerless, has dual MPPT, and high maximum string size voltage ranges. The Symo Advanced combines the benefits of the Symo with module level shutdown, which is a requirement in some states. The Symo Advanced inverters include an integrated PLC transmitter for SunSpec Rapid Shutdown and is compliant with both past and present NEC requirements. Like the Symo, the Symo advanced requires zero tilt mounting, is light weight and easily field serviceable.

The inverters are designed using Fronius's SnapINverter technology, which allows for easy installation and servicing. Installers can utilize the Fronius app to quickly and easily set up the inverter without having to open the inverter itself. Likewise, the inverter does not need to be opened to troubleshoot using the same software - unless indicated by the error that is being experienced. The light weight of the inverters allows them to mount to a number of wall faces, and the snap-in design of the hood ensures that the inverters are non-intrusive at the point of installation.

	SMA Tripower Core-1	Fronius Symo Lite	Fronius Symo Adv.
Size Range:	33kW - 62kW	10kW - 24kW	10-24kW
Average Efficiency:	97.83%	97.58%	97.25%
Average Cost per Watt*:	$0.12	$0.22	$0.30
Warranty Period:	10 Years	10 Years	10 Years
Downloads:	Tripower Specs SMA Warranty	Symo Specs Fronius Warranty	Symo Adv. Specs Fronius Warranty

*Averages based on pricing as of the posting of this article

Winner: Tie

In terms of size ranges, Fronius wins, however it is difficult to draw a direct comparison on price point given the wide variance in size range between the inverters. SMA pulls out slightly ahead with a better price point and higher average efficiency than Fronius. In the case of this comparison, which option is best for you is largely dependent on the scope of the installation. For mid-sized three phase systems, Fronius may be the best option, however large scale three phase systems will benefit from the fewer number of inverters needed to meet project demands.

SMA SunnyBoy Storage vs Fronius Symo Hybrid

The SunnyBoy Storage hybrid inverter is compatible with high-voltage batteries such as the LG Chem or Tesla Powerwall. The hybrid system is designed to act as an interface between the solar array and the electrical grid and provide backup power in the event of an outage. The inverters can provide up to 2000 watts of battery back-up power either at night when the panels are not generating energy, or during a blackout as previously mentioned.

The SunnyBoy Storage inverter allows for flexibility in project implementation, its AC coupled technology allows for installation according to your timeline - meaning you can install the system without battery backup and add to it later in the future. This can be very helpful when working within a set budget and allows for future options for the system owner should the need for energy backup power arise.

The Fronius Symo Hybrid inverter allows for surplus energy from your solar array to be stored via battery backup. Fronius's hybrid inverter is compatible with various third party batteries such as LG Chem or BYD, which makes them compatible for hybrid installations. A highlight of Fronius Symo Hybrid systems is that loads can be supplied at the same time the battery is being charged, even in emergency power mode.

Their Multi Flow Technology allows for AC and DC coupling to accomplish battery storage. The installation process can be difficult, it is recommended that Fronius couple systems be installed by a certified contractor, or checked off by a NABCEP certified electrician before being put into operation. To gain a better understanding of Fronius's AC/DC coupled systems, check out Fronius's hybrid installation guide. In addition, the hybrid inverters can be difficult to source.

	SMA SunnyBoy Storage	Fronius Symo Hybrid
Size Range:	3.8kW - 6kW	3kW - 5kW
Average Efficiency:	97.5%	97.8%
Average Cost per Watt*:	$0.46	$0.56
Warranty Period:	10 Years	10 Years
Downloads:	SunnyBoy Storage Specs SMA Warranty	Symo Hybrid Specs Fronius Warranty

*Averages based on pricing as of the posting of this article.

Winner: SMA

SMA's SunnyBoy Storage inverter comes in at a lower price point than the Fronius Symo. In terms of efficiency the ratings are comparable within 0.03% of one another. While the Fronius Symo Hybrids offer a comparable solution in terms of size range, SMA's more streamlined installation process makes it a more feasible solution for residential installs in most cases.

Warranty Comparison

Both SMA and Fronius offer 10 year limited product warranties across their various inverter lines. This means that both companies will cover replace defective inverters that fall within their respective criteria. This criteria falls within industry standards through comprehensive support and replacement for any inverter that is not damaged due to shipping or improper installation. Both can be easily ruled out and overall feedback on support and warranty claims have been positive for SMA and Fronius.

While their warranty offerings fall almost in line with one another, Fronius's warranty does not cover shipping costs to or from their facilities for replacement or costs of labor for replacement. SMA offers free ground shipping, with an option to pay for expedited shipping. Labor costs are not stated outright in their statement and are taken on a case by case basis.

For more in-depth warranty coverage, SMA and Fronius both offers extended warranty programs that will increase the years of coverage on your system, provide additional support as well as further grantees for shipping and labor cost coverage.

	SMA	Fronius
Standard Warranty:	SMA Warranty	Fronius Warranty
Extended Warranty:	SMA Extended Warranty Brochure	Fronius Warranty Plus Brochure

*Contact SMA or Fronius directly to learn more.

Winner: Tie

Although SMA wins against Fronius based on their coverage of shipping for their standard warranty period. Fronius's various warranty extension offerings do include a number of useful additions as well.

Solaris Recommendations

Based on the criteria of our assessments, SMA inverters win the comparisons overall due to their value-based price point, high efficiency and ease of installation. SMA's Smart Modules also give them in edge in terms of flexibility of design, and improving upon the efficiency of the system as a whole. However, Fronius is not far behind in terms of efficiency, technology and, in some cases, price point and can be an ideal solution for both residential and commercial installs.

In addition, both manufacturers are backed by years of research and have at various times proved to be leaders in innovation and energy technology. Their warranty periods are above average for string inverters, out doing the stabdard five and seven year string inverter warranties on the market. Their respective ten year warranty periods are beat only by two years by SolarEdge, who offers a twelve year warranty period.

If warranty is a strong consideration in your inverter selection, both inverter manufacturer's offer extensive and affordable warranty extensions so you can be secure in your investment into their technologies. Technical support is available through both their monitoring website and technical support channels, making it easy for installers and homeowners to quickly troubleshoot and solve any issues within their system.

If you are considering installing a single phase, three phase or hybrid solar system SMA and Fronius we recommend SMA and Fronius inverters. Interested in getting a residential or commercial solar string inverter system?

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