SOLAR POWER: WHEN QUALITY PREVAILS

You can’t go to a free camp these days without seeing an array of different sized and shaped panels

Over the last decade, portable and fixed solar panels have increased in efficiency and provide more power in a much smaller package, making that quick weekend getaway more affordable and appealing.
This has meant that the number of gadgets that come along for the ride is growing, meaning that keeping charge up in the battery is becoming more important to make the trip comfortable. So what makes a good panel for your application, and what should you consider?

Considerations
There are plenty of cheap and nasty solar panels around but when it comes to something you rely on, it’s worth taking the time to do your research before purchasing. We all know that you get what you pay for and if you go for the cheap option you will often end up buying quality the second time around, says Redarc.
Redarc suggests you consider where the manufacturer of this brand will be throughout the warranty period to back up its product, stating that just because it looks similar you still need to ask are the materials as good, and can you trust the claimed performance figures?
So how do you decide what is quality and what is not? There is no formula for working this out, and everyone has a different perception on value for money. How you use the panel (portable, mounted, blanket), how often you use the panel (every day, every weekend, once a year), what conditions you use it under and how big is the impact if it fails when you need it most, are all things to consider when selecting the right panel for you. At the end of the day, Redarc advises that you look to the brands you know and trust for other quality products on your rig. By doing this, it says, you will be headed in the right direction.
So beyond the branding, what else do you look for, posits Redarc?

Solar tech explained
There are varying factors that influence the level of charge that we can extract from the panel during daylight hours, says Redarc. These include panel temperature and shading from clouds or obstructions around the campsite, and the angle that the panels face toward the sun.
Polycrystalline and monocrystalline cells are cell types used in rigid (glass covered aluminium framed) panels. All crystalline solar panels, by their nature, gradually lose a small percentage of output as the temperature of the panel rises upwards of 25c. Monocrystalline panels generally do this to a slightly lesser amount than polycrystalline panels.
An amorphous solar panel on the other hand does not suffer this decrease in output at all until more extreme high temperatures, at which point you
will have packed up camp and headed for the nearest AC unit many degrees ago. This makes amorphous and monocrystalline the cells of choice for Australian conditions.

Performance out in the sun
Crystalline panels do not perform as well with partial shading, whereas an amorphous panel is only slightly affected by minor partial shading. The angle of solar panels to the sun is one of the factors that can quite easily be controlled with portable solutions, and once again impacts on the output of a crystalline panel the most.
A crystalline solar panel must be as perpendicular to the sun as possible to achieve best performance. Amorphous solar blankets are able to take better advantage of changes in light intensity and having a matt, non-reflective surface means it’s able to make the most of the light even at increased angles from the sun.

Why quality matters
Redarc says the greatest advantage of an amorphous solar blanket is the incredible flexibility and the fact it is extremely lightweight. Therefore, it says, the quality of the assembly of these panels is most critical as they are moved, folded, bent, squished etc. You can have a reasonable cell, but if it is just glued to some canvas then it won’t last long in the real world, Redarc cautions.
The same applies to the frame of rigid panels, whether permanently mounted or portable, the torsional forces and vibration experienced in any automotive application is enough to damage the cells and connections in a thinly framed panel. The quality of the cell can be reflected in the surface area also, with highly efficient cells needing less surface area to achieve the same output.
When you see a panel with numerous ‘pieces’ of cell all connected together, Redarc says you can tell that impure or poor-quality cells have been used with the worst bits of the original cell having been cut away leaving the somewhat useable remains to be strung together. Some of the cheapest examples of this even exhibit colour differences within the cell pieces or amongst the groups of cells, explains Redarc.
Any more than one cut in a single square cell (often only there to bump the voltage up quicker as they are series connected) would be the recommended limit, Redarc says, stating not only would you have many more connections to have potential issues with, but it gives you an idea of the quality and purity of the original cells – and cell purity is directly related to performance and longevity.

Finding the right solution
Redarc advises that the best thing to do is to seek advice from reputable auto electricians like a local Redarc Solar Installer and RV and 4X4 shops like the nearest ARB.
You can also use the Redarc Solar Calculator at www.redarc.com.au/solarcalculator to see how much power is needed for your setup.

For more from Redarc, visit www.redarc.com.au