I get the Harbor Freight flyers, and every time the price drops (on sale now @ $139.99) I get tempted to buy one. But, then I remember this review....

KE7LLU writes:
I'd like to throw in some information concerning "the harbor freight 45 watt solar panel kit" and those like it sold under different brands. Some of the info is from personal experience with a smaller Harbor Freight panel and the other is from what I've read and will share so you can draw your own conclusions.

I've had some misgivings about these 45 watt kits after I had purchased a small Harbor Freight 5 watt panel a number of years ago which is made of the same solar cell material as the larger 15 watt HF panels. When I bring it out to test, I've noticed that it just hasn't performed very well compared to other 5 watt panels I am evaluating. The output having actually decreased over the time I've owned it. I don't have anymore personal data other than that observation but it's left me with a knot in my gut every time someone has asked me about the 45 watt Harbor Freight panel kits.

Every so often I'd look for experiences on the net from people that have actually bought and put in to use the HF panels but they have been very few and most are only initial reports with no long term data such as the one here on eHam.

However, in my hunt to find meaningful data that would support my gut suspicions (I admit, I was biased by my own personal experience), I came across this review on Amazon.com: "M. Anderson's review of Sunforce 50044 60-Watt Solar Charging Kit" www.amazon.com/review/R2ZJLCRGOX7T0R

That led me to the report it mentions: www.humboldt.edu/%7Eaej1/aSiKenya_FinalReport_July2_05.pdf
or
www.humboldt.edu/%7Eaej1/JacobsonKammen_aSi_Kenya_EP07.pdf

In the report it shows some pictures of the panels being evaluated and reviews and shows those that were experiencing problems. They look similar/identical to me to the Harbor Freight panels which also are manufactured as I understand in Shenzhen China by the Topray Solar Company. By that association I could conclude that the panel design after almost 5 years hasn't changed much and any current and similar panels could be subject to the same failure rate as the study reported which was that of two sets of panels under different brand names but manufactured by the same company, 3 of 4 panels for one brand failed completely during the first few months of testing and 1 of 4 failed with the other brand. In addition the test showed that all panels from both brands showed a large decrease in their power output of over 50% in the short time they were in service. Meaning that after only a few months in the sun the panels were only supplying 6 watts of power from panels that were rated at 14 watts. (Note: the HF panels say 15 watts but under load their actual initial output is 12 watts or less) This 50% decrease in output would support what I've seen with my own HF 5 watt panel which is made of the very same solar cell materials as the larger set of 45 watt panels.

The Topray Solar Company also makes similar panels for Sunforce in 60 watt configurations which are sold by a number of different stores and shop such as Amazon, CostCo and Northern Tool. My experience with Sunforce support and warranty service are a whole other topic for discussion and I would not put much trust in them either.

The solar cell material in question is fairly easy to identify compared to other solar panels. The panels are made of an amorphous A-SI type solar cell material also known as thin-film. Please note that not all thin-film solar panels have the same problem as the Harbor Freight or similar panels but the panels made by the same manufacture maybe suspect. The solar cells in question have very long thin lines down the length of the panels about 3/8 inch apart like in Figure 2 or Fig 6 of the Humbolt test results docs linked above.

Source: www.eham.net/reviews/detail/6825