Independent Tests Winner

July 2016   

Norwegian Magazine Seilas made an extensive testing of competing solar panels in the 50-watt class. The test was first published in June 2016

Later the magazine Praktiskt Båtliv (Practical Boating) published an article based on the same measurements and conclusions.

The test focused on measuring the electricity production in reality like test conditions. The test also included an estimation of physical qualities and a comparison of the estimated lifetime.

SUNBEAMsystem Tough 50W Flush was pronounced the “TEST WINNER”.


The test layout

Electricity production in many real life conditions were measured. Such as cloudy weather, partial shadowing and different solar angles.

Further on the magazine compares the construction and physical properties of the tested solar panels. Size and weight were also taken into account for.

The magazine proposes that a 50W panel is suitable for keeping your batteries topped up. This is however followed up with the recommendation that most users will need 100W to keep up with their consumption on a modern yacht. They also tell the reader that in most cases it might be practical to utilize two 50W panels to reach the total recommended 100w.


General recommendations

The test contains much useful information for those who want to learn more about electrical systems on a yacht with a focus on solar panels. It is mentioned that ordinary lead-acid batteries are difficult to charge over 80% of its capacity with an engine alternator. To be able to top up and utilize the final 20% of the battery capacity, solar panels are needed (or a shore power charger).

You will also find a discussion regarding what to consider when purchasing a solar panel. An external expert advises against solar panels constructed with a metal backside or with bad junction boxes. The reason to this is that it might cause future water ingression in the solar panel.


Comparison of external features

When comparing the physical properties the Magazine’s favorite is the SUNBEAMsystem panel due to its tiny size and weight, smallest of them all. This is important because it makes it a lot easier to find a space for fitting of the panel.

The paper also made a note that all the other panels equipped with a junction box are prone to water ingress. SUNBEAMsystem unique Flush model completely lacks a connection box which is deemed as a big advantage.

Electricity Production

The core of the test was the extensive in reality measurements during several types of conditions. Measurements made was; maximum power, power after sunrise, power in the morning and power at noon. Then repeated during cloudy weather with sunrise, morning and noon measurements.

A comparison of the produced power while being partially shadowed were also made.

SUNBEAMsystem was pronounced the overall winner in the power production test.


Best in test

To summarize: ´The SUNBEAMsystem Tough Flush 50W was pronounced the test winner and the test board only had one minor complaint. Which was that the panel has got a slightly higher price compared to the tested budget panel alternative.


The article can be read in full here.



March 2016   batliv

In the yacht magazine Båtliv number 2/2016, SUNBEAMsystem was tested and compared to other options.


The newspaper notes that SUNBEAMsystem “Marine panels with the latest technology” had the highest efficiency in the comparison.

The tests was conducted in Stockholm, Sweden (59oN) at a solar radiation of approximately 800W / m2 had the following result


Panel Results (at 800W / m2 solar irradiation)
Foldable panel > 130 W / m2
Traditional solar panel with frame Up to 150 W / m2


Marine Panel – Latest technology (SUNBEAMsystem) up to 190W / m2


We at SUNBEAMsystem conclude that the magazine’s measurements provide an efficiency of our solar panels ranging from 21.25% to 23.75%. That is an average of 22.5%.


Installation Advantages

The Magazine upgraded two boats. Boat number one previously had a solid solar panel with glass front and aluminum frame. Boat number two had a thinner solar panel with traditional cells and a protective stainless steel sheet on the back that was needed to protect the older type of fragile cells.

On boat #1 the magazine installed two SUNBEAMsystem 30W (60W in total). It increased the total power by 17% utilizing the same surface area. There was a significant weight saved, 4.8kg compared with previous solar panels. As a bonus the minimal size enabled installation of 2x30W SUNBEAMsystem on a surface that previously could not be used with older type solar panels. Hence multiplying the total installed wattage.

Boat #2 was upgraded with 2 x SUNBEAMsystem 30W with a resulting increase of 20% compared to the previous installation. The junction box free installation was very much appreciated by the owner

SUNBEAMsystem notes that the sample boats on average increased the installed wattage by 18.5% just by replacing the old solar panels. We also note benefits for the owners such as no junction box to stumble upon as well as avoiding ugly cables along the deck. There was also a significant weight loss for both boats.

Output in the Swedish reality

On the boat #1 with a combined swivel and horizontal mounting, extensive measurements were made over the summer. They revealed good effect in all the different conditions that we suffer during a Nordic summer. During normal sunny conditions the mean production was about 7.5A   corresponding to 106.5 watts. This result is 89% of the normative effect, a much higher value than traditional panels usually produce.

To complete the test of 30W panels fitted on the two boats. The newspaper also did tests on dry land including two other sizes. SUNBEAMsystem 50W (Part No. SP50) And SUNBEAMsystem 60W (Art No SP60-12v). In this test, the air temperature was about 20 degrees Celsius, relative humidity 48%. The solar panel was directed straight at the sun at the peak of the day. The measurements were conducted 4 times with 4 independent measuring instruments to verify all values. The highest observed effects are shown in the table below (Wp)


Panel Results
SUNBEAMsystem SP50 (50W stamped effect) Wp = 51W
SUNBEAMsystem SP60-12V (60W stamped effect) Wp = 69W


Original article can be found in the Yacht magazine Båtliv No. 2 2016.


Mars 2013    

In The Magazine Photon’s long term test made over 2012 in Germany, SunPower solar panels produced 8% more energy compared to the top 10 out of 151 tested solar panels.


Jan 2013      

BEW / DNV conducted test on a fair amount of competing solar panels where SunPower solar panels produced 8-10% more energy per stated watt compared to the competitors.