SolarEdge vs. Enphase, A New Evaluation

Reme Meck, NABCEP-certified PV Installer

I’ve looked at Enphase vs. SolarEdge before from the view of reliability and energy production.  I also considered installation time, concluding that Enphase is superior due to not having to install a central inverter while SolarEdge does.  The reality of the situation is somewhat different, so I’m revisiting this conversation with a much-needed update utilizing new information and perspective.  My valuation focuses on three main points, installation time/labor, price of materials, and energy production.

Installation Time/Labor

Most Enphase systems require the installation of an electrical breaker panel to combine branch circuits into a single circuit for interconnection.  Each branch circuit can handle up to 16 PV modules.  Enphase uses a proprietary trunk & drop cable to connect the system together, which must be cut to length and properly dressed against the mounting rails.

The SolarEdge system more resembles a traditional string inverter in its wiring once the optimizers are installed.  There is no additional wire/cable required to connect the optimizers together.  Each circuit can handle up to ~5.2kW of power, or ~18-20 PV modules. SolarEdge also requires the installation of a string inverter, which requires two people to manage safely.

Since Enphase can only do up to 16 PV modules per circuit, on average there will be more “homeruns” in Enphase systems than SolarEdge, which can typically do 18 – 20 modules per circuit.  A “homerun” is where a circuit (AC branch or DC string) on the roof is wired back to a breaker panel/inverter near the point of connection with utility power.  More homeruns add cost, require more installation time and material, and create more points of failure in the system.

Even though the Enphase system doesn’t have an inverter to install, the overall installation time is very comparable.  This is due to a couple of factors.  The additional time needed to install the string inverter instead of a breaker panel is made up in easier/faster wire management up on the roof and fewer homerun circuits, making total install time between the Enphase and SolarEdge systems very comparable.  In conclusion, they’re too similar to say one is better than the other without more analysis.

Price of Materials

If you consider just the inverter equipment, SolarEdge is cheaper than Enphase by ~10%, depending on where you buy it from.  This is due to Enphase’s slightly higher raw product cost as well as other accessories required by the Enphase system (proprietary trunk cable, wiring accessories).  SolarEdge also includes monitoring out of the box without any additional hardware, which is another net savings.

Enphase has the benefit of all its accessories and trunk cable being designed to connect together with very little additional hardware.  Aside from the inverters and cabling, an Enphase system will require a very short list of materials to complete the installation.  This includes a rooftop junction box to transition from Enphase’s trunk cable to raceway wiring, cable strain relief glands, and wire & micro inverter attachment hardware (which are typically included with the solar racking system).  Some jobs will also require the installation of a dedicated breaker panel to combine branch circuits, but the hardware required to install this is identical to what is used to install disconnects and meter bases so it should already be on-site.

SolarEdge has the benefit of being a simpler system with fewer proprietary accessories, so installers have more freedom of choice in selecting their installation hardware for the job.  One issue with the SolarEdge system is the inverter enclosure requires Allen screwdrivers to open/close it.  While this is good from an anti-tampering perspective, it requires the installer to provide additional tools and equipment they may not have otherwise needed.  Aside from that, no other special hardware is required by SolarEdge that Enphase doesn’t also need (attachment hardware, rooftop J-box, etc.).

Even with the string inverter, SolarEdge is at least 10% less expensive than Enphase.  SolarEdge may require additional hardware to complete the project, namely string inverter mounting hardware and DC wire management, but these products are widely available.  Enphase includes more of the hardware and accessories required to complete the project out of the box, but the proprietary nature of these products carries a higher price tag.  SolarEdge wins the price battle, but Enphase gets a consolation victory in its ease of install.

Energy Production

My previous post references a report by PV Evolution Labs that concluded Enphase produces 2.4% more energy than SolarEdge.  I was also able to recreate these results using PVSyst.  That report is now two years old, and in the solar industry that’s ancient history.  The PV Evolution Labs report also used older equipment models for both Enphase and SolarEdge.  For this post, I’ve performed a new analysis using the following as the basis of design:

PV Module –       (20) Solarworld 280W (datasheet)

Inverters             (20) Enphase M250 microinverters (datasheet)

(20) SolarEdge P300 optimizers (datasheet) w/ (1) 5000W SolarEdge Inverter (datasheet)

Locations – Albuquerque NM, Fresno CA, & St. Louis MO

Results (VCF files and PVSyst reports available upon request)

Annual Energy Production (kWH/year)
Location Enphase M250 SolarEdge P300 % Difference
Albuquerque, NM 9941 9870 0.71%
Fresno, CA 9059 8992 0.74%
St. Louis, MO 7695 7639 0.73%

 

This new analysis shows different results, and these results are consistent across different locations.  SolarEdge has closed the gap in performance between it and Enphase, and now less than a percentage point separates them.  Enphase still produces more energy than SolarEdge, and would be the choice for a system looking to maximize its energy yield.  However, the gap in energy production between Enphase and SolarEdge is small and getting smaller.

Conclusion

Enphase and SolarEdge are both viable options for a solar project.  SolarEdge has lower equipment cost and slightly lower production.  Enphase has higher equipment cost and slightly higher production.  Installation time is roughly the same.  As an aside, Enphase is seen as the safer option than SolarEdge, since Enphase micro inverter systems never exceed 50V DC while SolarEdge is designed around 350V DC strings.  Enphase also has more design flexibility, but SolarEdge’s monitoring and system commissioning is superior.  There are dozens of factors determining whether Enphase or SolarEdge is the right choice for your project, and I’ve only explored a handful of them here.  If you want to maximize your energy yield, Enphase is still the choice.  From a price perspective, SolarEdge wins hands down.  Call us today and we’ll help you make the right choice for your project!

Reme is one of Affordable Solar’s most valuable employees. His system engineering experience and expertise makes him one of the best in the industry.

14 Comments

  • Mike Rogerson

    need to see those PVSyst files.

  • bob

    AP system?

    • Marge

      You mean I don’t have to pay for expert advice like this anyorme?!

  • john nagyvary

    How is SolarEdge monitoring and system commissioning superior? I’ve installed these systems and both of these aspects are quite straightforward and simple.

  • Michael Douglass

    The SolarEdge operating voltage of 350 VDC versus the Enphase 240 VAC reduces the ampacity needed in home run cables by a third and additionally only is 2 wire (plus ground). This can be a significant savings for ground mount systems located at a distance from the panel. Also, Enphase requires more breakers and panel space for the same size system.

    • Bon

      Wires that carry AC can be sized smaller than equivalent DC.

  • Robert Silvers

    But EnPhase loses up to 1% a year due to clipping that wipes out the 0.7% advantage.

    • Scott Chazdon

      What? What clipping. I monitor all the systems we have installed and have not seen any clipping.

  • Sher Doncas

    Need to see your files. .73%? What you talking

  • Diwakar Shetty

    The part about safety is the most important for me so far as installing on my home is concerned. Won’t the micro-inverter create 240 AC on the roof? Not that safe but still safer than the 350V DC of SolarEdge on the roof.

  • Asgar Irani

    Which system is better when you add a battery backup system to either system? I am told enphase being an AC current can not easily handle this and the micrometers switch on/off constantly to a point the wear out. Can someone shed some light on this. Thank you.

  • Eve Leland

    Does the EnphaseS280 allow monitoring of individual panels?

  • scott b

    What’s the cost difference? Is the cost difference including replacing the solaredge inverter once over 25 years?

  • Dan Staples

    Nobody is discussing heat in this thread. I have been told that in “High Heat” areas like Phoenix where it can easily get to 120+ degrees the SolarEdge inverters out-perform the Enphase inverters by a big margin. The hotter it gets, the worse the Enphase inverters look in the comparison. I have not done any testing myself and have no data on this but it is what I am being told by other Solar Installers. If that is true, why isn’t anyone discussing the heat issue. It doesn’t get hot enough in most places in California to matter but in Phoenix it does matter.

    Can someone who knows more than I know – confirm or deny this?

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