Marine Solar Installations: why they’re unique

(Last modified on January 26th, 2022.)

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Sun Pacific Solar Electric solar installation at the Santa Barbara Natural History Museum Sea Center in a marine environment using IEC 61701 tested panels.
One of Sun Pacific Solar’s marine solar installations, this one for the Santa Barbara Sea Center on Stearns Wharf.

Marine solar panel installations. Simple, right? Not so much.

Installing solar in a marine environment, weather on a boat, near the waterfront or in a coastal zone is drastically different than building a solar power array in other areas. The main difference is that the materials used must be non-corrosive – this includes the nuts, bolts, rails, mounts and most importantly, the solar panels themselves. This is because some material warranties are voided if installed in marine regions.

Here’s the important questions we’ve answered:

  1. What is the IEC 61701 test and how do we interpret the results?
  2. What manufacturers warranty their panels in marine environments and how are these areas defined?
  3. Are IEC 61701 Certified solar panels warrantied in marine areas?

The Salt Mist Corrosion Test

The International Electrotechnical Commission (IEC) set a standard for salt mist resistance for solar panels with their IEC 61701 test. And although it’s intended to help consumers make more informed decisions, the reality is to be taken with a grain of salt (pun intended).

In the test, photovoltaic panels are misted with a salt water solution for a duration of time and their corrosion resistance is rated between 1 and 6.

Here are the test levels explained:

  • Level 1 – intended to be used for PV modules installed in marine environments or in close proximity to the sea.
  • Level 2 – not suitable for PV modules as the testing conditions are too weak (this level was originally intended for products exposed to corrosive environments from time to time that are normally protected by an enclosure) and should be avoided when applying the IEC 61701 Standard.
  • Levels 3 to 6 – intended for PV modules operating in locations where there could be a change between salt-laden air and dry atmospheres, for example places where salt is used to melt ice formations.

After undergoing the IEC 61701 test, solar panels are inspected. Power measurements are made, insulation is tested and panels are visually examined. No visual defects are permitted and power degradation cannot decrease by more than 5%.

However, here is the said grain of salt.

We have found that the IEC 61701 Salt Mist Corrosion Test is not always listed on spec sheets. And when it is, the resulting grade assigned is not always included. It’s also possible for different panels by the same manufacturer to obtain different IEC 61701 ratings. However, when a rating is included, it can be found in the data sheet’s “certifications and warranties” section.

How Warranties Describe Marine Areas

While you may think voided warranties only apply to installations directly on the water, this can also include solar arrays in broader coastal zones.

The definition of this zone and the specific language differs by manufacturer. And for a location like Santa Barbara, where the bulk of development is within two miles of the ocean, this language can have a substantial impact.

  • SunPower – PV panel warranty exclusions include installations “in locations, which in SunPower’s absolute judgment may be subject to direct contact with bodies of salt water.” The IEC 61701 test is listed on some data sheets.
  • LG – IEC 61701 test listed on some spec sheets, but their general warranty voids panels subject to damage and/or failure due to rust and direct contact with salt water.
  • Lumos – IEC 61701 test not listed on specification sheets. The Lumos panel warranty is void for installations in locations subject to and damage/corrosion resulting from direct contact with salt water.
  • Panasonic – panels IEC 61701 tested but not warrantied for marine installations (such as boats), or damage or corrosion resulting from direct contact with salt water such as ocean spray, or damage from rust.
  • Hyundai – warranty not specific but refers to their installation manual in which they state “modules shall not be installed in salty area within 500m (546 yards) from a body of salt water and/or area where salty winds hit directly. When modules are installed 7km (4.3 miles) from a body of salt water, the installer should check salt damage of the installed area.” Their data sheets state the panels have passed harsh salt mist tests, though they don’t site the IEC 61701 test specifically.

The Warranty Takeaway

Even if a solar panel has an IEC 61701 rating, it does not mean that the manufacturer warranties its solar panels in a marine environment. Deceptive? Yes!

Marine solar power installations are tricky. The manufacturers we’ve singled out above are the ones we’ve rated as Top 5 on the market, so doing this research for other manufacturers is even more important! This is why it’s important to read the fine print of solar warranties and choose an experienced solar installer.

Sun Pacific Solar’s installation at the Santa Barbara Sea Center, on Stearns Wharf, and the many installations we’ve done on boats are just some examples of our arrays in direct marine environments where special considerations had to be taken into account.

The quality and longevity of our installations are our top priorities, so we always use durable materials and adhere to their installation guidelines.

If you have additional questions regarding solar warranties or panel manufacturers, don’t hesitate to reach out!

2 thoughts on “Marine Solar Installations: why they’re unique

  1. Hi Ceci! Thanks for this helpful article. I´m a certified installer in Veracruz the Gulf of Mexico coast and some information on the web regarding the corrosion resistance of solar modules seems vague or confusing. For instance, the following note interprets the severity scale of the IEC 61701 norm different: , it states “If you want peace of mind you can get yourself a panel with level 6 resistance.”

    I would appreciate a lot confirming whether the modules installed within 200m or so of the coast should have the 61701 severity 1 or 6. I usually install Jinko, JA Solar, Canadian solar and at least all Jinkos modules have the IEC61701 severity 6 but I dont know if this rating if the highest of the lowest.

    Thanks, regards!

    1. Hello Marcelino, thank you for your question. It’s difficult for me to elaborate on the quote and article you linked because I do not know what source the author referred to for that information. However, the source I referred to for the IEC61701 severity breakdown is linked in our article. The speaker on the video is reading directly from the IEC (the International Electrical Commission) guidelines and given that this is the entity that established these standards and the related testing procedures, I am more inclined to trust this source. I think maybe the author of the SolarQuotes article also found this video resource but interpreted the information differently. After going through the explanations of the levels, the video talks about Australia’s Clean Energy Council’s interpretation of IEC61701. This Australian entity determined that although level 6 is the IEC’s least severe salt mist corrosion level, it deemed this test result to be adequate for PV installations in coastal areas, as close to 500 meters to the sea. This is the exact opposite of how the IEC should have been interpreted, hence the speaker’s confusion at the end of the video. But given that this ruling is only applicable in Australia, it has no bearing on the US or Mexico. I am not familiar with Jinko, JA Solar or Canadian solar warranties, but as our article outlines, just because the panels have been tested and given an IEC61701 score, it does not mean the manufacturer warranty will allow for module installation in a coastal zone or marine environment. Reading through the manufacturer warranties is the only way to know what will void it.

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