The market for portable solar modules and chargers is growing with multiple brands entering the market.The mobile solar market is growing in tandem with the impressive growth in the mobile handheld device market and the wearable markets.
In the past, portable solar chargers were considered a "green" product emulating a "green" lifestyle.While this can still be somewhat true, the portable solar products are now being tailored for the outdoors enthusiast, outdoor professionals, and in military applications.The purpose is more focused on performance and convenience for the mobile lifestyle (not just "green").
The cost of the solar panels have decreased, along with the standard crystalline panels used on residential and industrial solar arrays. The standard residential panels have reached commodity levels when considering availability and pricing.
"You get what you pay for"
Price has always been a factor when considering a solar product.In residential solar, the common metric is the final cost per watt of electricity provided for the home.The solar panels themselves are rated and marketed on a cost-per-watt price point.
Portable solar chargers are slightly different. If the manufacturing steps are the same, the smaller panels carry a higher cost per watt due to the decreased output from the smaller surface area of the panel. The value lies in the portability, convenience, and necessity (Compare a desktop to a laptop computer; pay a premium for the portability).
The standard residential panels adhere to industry standards in manufacturing and testing and are often tested by third parties.So you can be reasonably sure that a reputable manufacturer will meet industry standards and be of decent quality.
The smaller mobile solar charger market has not followed the same path.These products are not held to any industry standard and usually not tested by any third party.Many brands are far over-stating the power output of their solar charging products.These panels could be of questionable quality and durability, so a low cost folding solar charger could perform under the marketed specs and not withstand the hands-on often rugged treatment of a portable, outdoor product.
Look for a company that has tested their products and share their results.Look for actual durability testing, long-term tests, and output performance testing.I have personally used some inexpensive solar garden lights that didn't last the summer. The coating on the panels were not UV protective and clouded up after exposure to the sun.
The old saying, "you get what you pay for", definitely applies to the portable solar market.
What are Thinfilm and flexible panels?
Thinfilm and flexible have become broad terms that are not well defined in the solar industry.These days, thinfilm is not a technical term and more of a marketing term.Some companies are turning to other terms like "rollable", "paper-thin" or "solar paper" to differentiate their products from others.Flexible is another term that is loosely defined.The problem is, how flexible is it?Is it semi-flexible or semi-rigid, how much can it flex, can you roll it, what radius can it bend before breaking or other damage would occur?
So be aware that the terms "thinfilm" and "flexible" can apply towards different solar cell technologies and the properties can vary widely.Look for a thinfilm panel that can flex the amount you need and on a substrate that is still durable.
Compare CIGS flexible, to silicon crystalline panels
Standard silicon crystalline technology has been around for a long, long, time.With modern manufacturing techniques and the basic laws of supply and demand, these solar panels are now low cost and the resulting energy cost is almost on par with fossil fuel generated electricity.
Copper Indium Gallium Selenide (CIGS) technology does not use silicon and can be applied to flexible substrates instead of glass. The manufacturing methods are not as efficient and cost effective resulting in a higher cost per watt. Arguably, more effort could be focused on the manufacturing techniques and efficiencies and bring the cost of CIGS panels down to more acceptable levels.
The real advantage of CIGS is the light-weight, flexible solar modules that open the door for non-standard designs and applications.This includes Building Integrated Photovoltaics (BIPV) and on mobile devices with limited flat areas and flexing surfaces.The resulting products typically have a lighter weight and no worries of breaking or cracking glass, with an expected lifetime of 15 to 20 years on well designed products.
What fills your need?
When considering a portable solar charger, consider your environment, intended use, longevity, quality, features, and price.For example;
Light-weight - Will you be carrying the charger around with you? If so, are you hiking or camping where weight or payload is a factor.
Size - Again, will you be carrying the charger around with you? Consider a small charger or a folding charger that can fold up for compact size and/or fold out for more charging power.
Flexible - Will the solar charger be exposed to conditions that could damage or crack a glass panel? Sometime rough handling can damage a solar panel, so a flexible panel could reduce any damage and even absorb some of the shock.
Enough Power - What are you trying to charge? How many devices do you want to charge? Check the specifications on the device you are trying to charge.A laptop will typically require more power than a cell phone or a couple of rechargeable AA batteries.
Quality - How long will the solar charger last? Be sure the solar charger meets the marketed specifications for power output. Also be sure the final product is manufactured well and carries a decent warranty.
Price - Price is always a factor and there are multiple ways to compare or rate solar chargers.Whether you are comparing a cost-per-watt, or features on the charger, rugged qualities, type of solar, etc... Be sure to compare the facts, not the hype.