Reasons to Get Solar Panels and What to Consider When Buying

Want the ultimate freedom to traverse the vast land mass that is Australia and still have access to electricity? Hulking around a huge generator while using tons of fuel is one option. The other is having some form of solar. The second option is an environmentally clean and virtually maintenance-free alternative that won’t be an eyesore, or wake the neighbors in the campsite in the middle of the night. If you’re set on solar panels for your 4WD, campervan, motorhome or RV, there are a few interesting choices in terms of designs, sizes, and power output. The type of vehicle will be one factor determining what you get, another is your overall power needs to run all the devices and appliances you have onboard.

How do Solar Panels Work?

First, the tedious science lesson that explains the magic behind solar panels and how they produce electricity. Power and electricity in solar panels rely on electrons and knock them off their backsides when energised by photons present in sunlight. This happens between the positive and negative poles of the dozens of photovoltaic cells comprising the panels. Basically, electrons in positively-charged phosphorous layers are swept off their feet towards the negatively-charged bottom boron layer, much like a tumultuous love story. Both top and bottom layers are encased in silicon, with a barrier that allows for the flow of electricity. The purity of the silicon is what makes for different types of panels, and impacts overall efficiency.

The resulting power though needs to be transferred and this is done by conductive wire leading the charge to the edge of the panel. The generated current passes through a charge controller or solar regulator which controls the voltage and current reaching the batteries. The powering of any devices or larger appliances is achieved by simply hooking them up to the battery.

Which Type of Solar Panel is Right for Me?

While the working principles are the same in both fixed residential and portable setups we find in campervans and RVs, there’s more variety in solar panels on offer for the latter, and this can make choosing what’s right a bit harder. Solar panels differ in design and the way they’re fitted. Some buyers will prefer fixed solar panels, especially if the roof realty space is abundant, while anyone with restricted space might go with portable panels in a smaller size. Either way, you’ll need the right number of panels to get all the power you need.

You’ll find monocrystalline, polycrystalline, PERC and thin-film panels. Let’s see how they’re different as prices can range wildly among the different types. Monocrystalline panels are the traditionalist’s choice, with the purest form of silicon, often made of a single piece, and this aids in the conductivity and resultant efficiency. Monocrystalline panels are recognisable by their clean, bluish tint, which is not the case in polycrystalline variants. These have smaller, broken fragments of silicon. The slightly lower power output compared to their monocrystalline siblings though means they’re cheaper to buy.

A newer take on mono panels are PERC or Passivated emitter and rear cell panels that have the highest efficiency and some of the highest prices. They are more complicated to produce, since the additional bottom or rear layer helps to better absorb sunlight.

Lastly, choose thin-film panels in flexible designs if you’re fitting these to uneven surfaces on RV or campervan rooftops. These benefit by moulding to just about any surface, so are ideal for a range of different vehicles, but the tech isn’t there yet to equal the efficiency and output of mainstream monocrystalline panels.

Fixed or Portable Panels? Which is Best?

Choosing between a panel that is fixed to the roof of your vehicle or one that can be moved around to capture the most available sunlight has been a heatedly-debated topic. Neither a fixed nor portable solar is better than the other, but they each have their pros and cons, meaning they’ll suit different buyers.

Fixed panels are a set-and-forget option, but one that relies on more space, as panels that spurt out higher power can get big. If you have more going on in the RV or motorhome in terms of energy needs, maybe an aircon, fridge or microwave, then you’ll need several fixed panels to get these appliances running, as well as the right battery setup to store all the generated power. These panels are reserved for bigger solar setups, and ones that will have expensive inverters and monitors to have a painless supply of power when you need it.

Another aspect to consider is the build. Fixed panels will bear the brunt of bad weather, so need thicker glass to absorb impact, and something that ups weight. The upside is that panels will be charged both while driving and when parked, but you’ll need to have the RV or campervan constantly in the sun, and this is not always desired or possible when reaching your destination. Other than that, they are a low-maintenance option that also delivers the most power.

Portable panels come in a few different designs. Folding panels for instance will be two smaller panels in the fixed design, but separated by a hinge to allow them to be folded. There’s some logic behind the idea, especially in terms of space, but the weight is comparable to larger panels -in excess of 10 kilos. The downsides are usually lower efficiency and higher price. For campers that don’t have special power needs, one portable panel set directly in the sun and connected with cables to the rest of the system may be more than enough. This frees up space on roof racks or vehicle roofs for other items. Just consider the boot space when stowing it away.

Flexible thin-film panels are a good option for anyone working with difficult surfaces. These can take up the same rooftop space as fixed panels, but also other areas to absorb the most sunlight. The higher price and slightly flimsy build offset their lower weight. They score points on practicality but lose out on overall efficiency. Casual campers and anyone only needing to charge only a few lights and portable devices will be happy with either a solar mat or blanket. They’re decently built, being newer options on the market, and also have a decent output for their size. Mats are more practical in bad and cloudy weather, with included stands that can position the panel directly in the sun and maintain stance in stronger gusts. And they’re quick to set up or pack without taking up too much space.

What to Look For in Solar Panels?

1. Efficiency – this is how much of the absorbed sunlight the panel can convert into usable power. Fixed monocrystalline and PERC panels lead the way here, coming close to, or exceeding 25 per cent of the rated power. Similar numbers are found in solar mats with the same monocrystalline design. Lower levels are common in polycrystalline panels, ranging about 20 per cent, while thin-film panels fare worst.
2. Rated Power Output – this goes hand in hand with efficiency. The larger the panel the more power it can garner. The biggest mono or PERC panels are capable of a rated output of 400W, while decently sized mats and blankets gravitate towards 200W. Consider your overall power needs and get the panels in the right output
3. Size and Weight – This can be an issue for most casual users, as hauling or setting up larger panels can become an unnerving hassle pretty quickly. Fixed panels are large and take up all the space on the roof, so forget about fitting anything else here. Users though won’t need to worry about the weight. In this respect, mats and blankets are more practical options than folding panels, being easier to move around and considerably lighter.
4. Price – Thin-film and PERC panels are the most costly, while the middle ground is occupied by decent fixed monocrystalline panels. The added functionality of portable variants can up the price. Often, you’re getting your money’s worth regardless of which type you choose. Panels with included regulators will demand a slight premium, but save money when you have to buy this and any extra gear.