Enphase vs SolarEdge inverters: reliability, specs, features

When it comes to buying a home solar system, homeowners often focus their attention on choosing the best solar panels. However, arguably the most important component isn’t the panels, but the inverter.

The inverter does the work of converting direct current (DC) power from the panels into alternating current (AC) power that your home can use. It’s the most complex device in the system, and the component most likely to experience failures.

Also, if your property experiences difficult lighting conditions - meaning significant shade for at least part of the day - the type of inverter you choose can have a big impact on your energy production.

For these reasons and more, it’s important to select the right type of inverter for your home solar project. Over 80% of the US home inverter market is dominated by just two companies: Enphase and SolarEdge. If you get multiple solar quotes, probably at least one of them will include Enphase or SolarEdge, and it’s also likely that you’ll be comparing one with the other. That’s where this guide will hopefully help you make an informed decision.

Module-level electronics: microinverters, power optimizers, and rapid shutoff devices

According to Tracking the Sun, an annual report by Lawrence Berkeley National Laboratory that summarizes solar industry trends, 94% of residential solar installations now use module-level power electronics (MLPEs).

That’s industry lingo for electronics that are attached to every panel (ie. module) in a system. MLPEs include microinverters, power optimizers, and rapid shutdown devices.

As you can see in the chart above, both microinverters and power optimizers are extremely popular in small solar installations. With large scale solar projects, power optimizers still have significant market share, but the usage of microinverters is minimal. This is most likely because of the cost premium of microinverters compared to other types of inverters.

One reason for the increase in the use of MLPEs in the past decade is the requirement for home installations to have rapid shutdown capability, which is a safety feature that lets first responders cut the electricity in the wires on a roof in the event of an emergency.

Rapid shutdown is accomplished with the use of MLPEs. Both Enphase microinverters and SolarEdge optimizers perform this function. There are dedicated devices like the Generac SnapRS that provide only rapid shutdown features, but it doesn’t cost much more to install an Enphase or SolarEdge MLPE, which reduces their popularity.

Enphase microinverters

The Enphase product lineup includes microinverters, AC solar panels, and batteries. They do not offer string inverters.

The newest Enphase microinverters are the IQ 8 Series. They improve on the earlier IQ 7 with higher capacity models, making the IQ 8 Series suitable for pairing with the latest 400+ watt panels that have arrived on the market in the past couple of years.

There are six models to choose from: the IQ8, IQ8+, IQ8M, IQ8A, IQ8H, and IQ8H 208v. The main difference between these models is the input and output power. Most home installations will only need either the IQ8 or IQ8+, as the latter tops out at 440 watts of input power. Only larger panels aimed at the commercial market will need the higher capacity IQ 8 models.

One other new feature of the IQ 8 series is Sunlight Backup, which is the ability to provide limited power output during a blackout without the need for a battery. (Standard solar inverters shut down during a blackout unless the system is coupled to a backup battery.)

Sunlight Backup means that your system can supply power to your home during a grid outage as long as the sun is shining. That might be enough to power a window air conditioner, gas furnace, or help keep your refrigerator from defrosting.

However, Sunlight Backup isn’t a free feature. It requires an additional component called the IQ System Controller, which currently sells online for $1,700. That doesn’t include installation, so it’s a pretty expensive feature with arguably limited use. However, if you do experience frequent blackouts but don’t want to go all-in with an expensive battery system, Sunlight Backup could be a nice option.

Enphase AC solar panels

Another Enphase product is AC solar panels. If you’re not familiar with AC solar panels, you can read my article for a detailed explanation.

The short explanation is that all solar panels produce DC power, but AC panels come out of the factory already paired with a microinverter (that’s mounted on the back of the panel).

The advantage of AC solar panels is that they save the installer a bit of labor, and they can also be cheaper than buying the panel and microinverter separately. The downside is that you have fewer choices compared to purchasing any panel on the market and pairing it with a microinverter.

Enphase partners with four panel manufacturers, which gives you some choices: they offer panels from SunPower, QCells, Panasonic, and Solaria.

SolarEdge inverters

SolarEdge offers central inverters that work with power optimizers. (SolarEdge does not offer a traditional standalone string inverter.) Their inverter for residential use is the single phase HD-Wave inverter. There is also a three phase HD-Wave, but that is for commercial use. (Homes in the United States almost never have three phase power.)

With the SolarEdge system, there is a central inverter that is installed in your basement, garage, or on an outdoor wall at ground level. It handles the DC-to-AC conversion for all the panels in the array.

There are seven products in the HD-Wave lineup. All of them share the same features except for power capacity. Here’s a list of the HD-Wave inverters by input power:

All inverters in the HD-Wave series require the use of power optimizers.

Power optimizers are a component that improves the efficiency of a solar array, especially in situations where some of the solar panels experience shade for part of the day.

Similar to microinverters, one power optimizer is wired into each solar panel. The optimizers allow the system to handle shading situations better than a string inverter, and also give you panel-level monitoring.

From a technical point of view, a power optimizer is a maximum power point tracker. An MPPT unit allows an inverter to better deal with partial shading, a situation that could cause the entire array to lose power generation if not compensated for. While a conventional string inverter might have 1 to 3 internal MPPT units, with a power optimizer system there is one MPPT per solar panel. This allows the solar system to get maximum electricity generation in partial shading situations.

Which inverter is more reliable: Enphase or SolarEdge?

Unfortunately, there doesn’t seem to be any hard data with which to compare the real-world reliability of Enphase and SolarEdge hardware.

The second generation of Enphase microinverters, which was released in 2008, was known to have an unacceptably high failure rate. The company launched a replacement program that owners of M175, M190, M210, and D380 microinverters can take advantage of.

Since then, Enphase microinverters have seemingly been much more reliable. They are currently on their 8th generation.

Enphase offers a 25 year warranty for its microinverters. SolarEdge power optimizers also come with a 25 year warranty, but their central inverter has only a 12 year warranty. However, you can extend that warranty to 20 or 25 years for about a couple hundred bucks.

So both companies offer similar warranties, but without any concrete data, is there any way to know which brand will actually be more reliable?

The best I can do is offer an opinion, which I’ll warn is based entirely on anecdotal reports I’ve heard from some installers. Take it with a very large grain of salt.

With that said, it does seem that there are more reports of SolarEdge failures than Enphase, particularly of the central inverter. This is notable because a failure of a central inverter will knock out your entire system. In contrast, a microinverter failure will affect only the panel its attached to. This means that even if Enphase and SolarEdge had similar failure rates, the impact of a central inverter failure is significantly higher than losing even several microinverters.

Again, this is only based on anecdotal reports, which probably isn’t very useful to help you make a good decision.

Instead, I would focus on making sure that you understand your installer’s warranty and how long they will cover the labor cost of any hardware repairs on your system. Downtime isn’t that bad if you have a responsive installer who can promptly schedule a repair.

Efficiency comparison

Efficiency in an inverter refers to how much of the DC input is converted to AC output. The process isn’t 100% efficient: some percentage of electricity will be lost as heat.

The good news is that both Enphase and SolarEdge systems are highly efficient, and have basically the same efficiency.

The latest Enphase IQ8 microinverters have a listed efficiency of 97%. That means 3% of the input electricity is lost as heat.

With a SolarEdge system, you need to look up the efficiency of both the central inverter and the power optimizers, and multiply the two numbers to get the total efficiency. The HD-Wave Inverter has an efficiency of 99%, while the power optimizer has an efficiency of 98.8%. If you multiply the two, you get 97.8%.

This means both are very similar, with SolarEdge perhaps having a very slight edge, but in reality the actual efficiency of your system will be affected by things like the length and thickness of your cable runs.

Warranty comparison

As mentioned before, Enphase microinverters and SolarEdge power optimizers both have a 25 year product warranty. SolarEdge central inverters comes with only a 12 year warranty. SolarEdge offers 20 and 25 year warranty extensions, but for an added cost.

Here’s the current pricing (as of 2023) for SolarEdge warranty extensions:

The warranties for both Enphase and SolarEdge cover product failures, but do not include installation labor.

Enphase vs SolarEdge pricing

In general, a microinverter-based system will be the most expensive option, a power optimizer-based system will be somewhat cheaper, and a string inverter will be the least expensive.

That said, the actual price you are quoted can be significantly influenced by the installer, who may have manufacturer partnerships or volume discounts. Because of this, you can certainly get a bid where Enphase is cheaper than SolarEdge.

Here’s some more data on real-world pricing from Berkeley Lab:

This graph shows that for residential projects, the difference in average total system price for systems with microinverters and power optimizers is quite small: about 10 cents per watt. This means that it’s certainly possible to be quoted on a microinverter-based system that is cheaper than an equivalent one with power optimizers.

Monitoring systems

Both Enphase and SolarEdge give you panel-level monitoring that is available via the web or a smartphone app. You’ll be able to see power generation in real time, and you can create reports on how many kilowatt-hours of electricity your system has produced on any day, week, month, or year.

Both systems also let you see how much power each individual panel generates, which is a great feature to help you monitor the health of your system and to know when one panel might be having a problem.

You can preview what this looks like by checking out any of the public systems that are available on the web. While the web portals that SolarEdge and Enphase provide don’t match exactly what their smartphone apps look like, it gives you a good idea of the detail available.

With an Enphase system, monitoring is provided by a separate product called IQ Gateway. It communicates over Wi-Fi or cellular to send data to Enphase servers. A SolarEdge HD-Wave inverter, on the other hand, has the monitoring system built into the device.

• SolarEdge demo site (select any system on this page)
• Enphase demo (The Solar Nerd house!)

Finally, both SolarEdge and Enphase also offer electricity consumption monitoring. The installer clamps a device called a current transformer around each of the two main feeder cables in your main electrical panel. With these devices in place, both the SolarEdge and Enphase apps will let you see how much electricity your home is consuming and how much solar electricity your panels are generating. This can be particularly useful if you don’t have full net metering and need to minimize the amount of electricity you sell to the grid.

Enphase Energy and SolarEdge: financial picture at a glance

One more thing to consider is the expected longevity of these companies. Solar equipment is different from many other products that consumers buy. You don’t expect your television to last 25 years, so multi-decade warranty support isn’t an issue. It’s a different story for solar equipment, because a 25 year warranty does you no good if the company has gone out of business.

I’m going to preface the following by saying that I’m not a financial expert in any way. I’m just reading the income statements for each company.

While both companies have been profitable for the past three years, Enphase Energy (ticker symbol: ENPH) seems to be in a better financial position. While both companies are profitable, Enphase had a net income of almost $400 million on a total revenue of $2.3 billion in 2022, while SolarEdge Technologies (ticker symbo: SEDG) had a profit of only $93 million on $3.1 billion in revenue. SolarEdge also burned through some cash last year, while Enphase had almost $700 million in free cash flow.

On the other hand, Enphase is carrying more debt than SolarEdge.

Again, I’m not a financial expert in any way at all, so I recommend clicking on the links above and doing your own analysis.

Enphase vs SolarEdge: which should you choose?

Enphase and SolarEdge are the 800 pound gorillas in the residential solar market, so if you get multiple solar quotes (as you always should) there’s a good chance that you’ll see quotes for both products.

Both Enphase and SolarEdge inverters are excellent, so you shouldn’t be afraid of making a “wrong” decision. Chances are, whichever manufacturer you go with, your system will work trouble-free for a couple decades.

That said, there are a few reasons why you might lean toward one or the other.

Shading: Microinverters will generally outperform power optimizers in difficult shading situations. Even though power optimizers are can limit the impact of partial shading, they will fail to work when too many panels in a string are covered in shade. Microinverters, on the other hand, have no such limitation. If your installation is impacted by trees or a complicated roof that throws shadows, a microinverter-based system may perform better.

Future expansion: You’ll notice in the list of SolarEdge HD-Wave products above that each has a power input limit. This limit means that if you expand your system in the future - as might happen if you purchase an electric vehicle, for example - the additional panels may exceed the power capacity of the inverter, and you’ll need to throw it out and purchase a larger one. Microinverters don’t have this design limitation: you simply add more panels and microinverters to your array. For expandability, microinverters have a clear advantage.

Reliability: Enphase might have a better reliability track record, but again I’ll emphasize that it’s my opinion based purely on anecdotal reports I’ve heard. Regardless, I think it’s safe to say that a microinverter-based system is more resilient because it doesn’t have a single point of failure. If you have one microinverter fail in your array, you might even choose to ignore it rather than pay for the repair labor.

Warranty: The 25 year Enphase warranty exceeds the basic 12 year SolarEdge warranty. You can get 25 years with SolarEdge, but it’s an optional add-on with a cost.

Price: In most cases, SolarEdge systems are cheaper than Enphase - but not always.

Final note: a string inverter might be just fine

Finally, it should be noted that if your solar panels are being installed on a single flat section of roof and you have no shading issues, your best value might be a string inverter. While a 10 year warranty for a single inverter is typical (meaning that you should plan for at least one replacement during your system’s lifetime), the cost of a string inverter is also considerably cheaper than microinverters or power optimizers. In addition, the labor cost of replacement is lower because you don’t have to go up to the roof to replace components. Read our guide to solar inverters to learn more about this topic.