How To Choose the Best Solar Panel for Free Camping in Australia

Adding solar panels to your setup is one of the easiest and most efficient ways to charge your dual batteries so you can keep your food and drinks cold while staying at your favourite remote destination.

Choosing the right solar solution can be confusing and even overwhelming, even for those who have a good understanding. After all, solar technology has come such a long way that there are hundreds of brands out there in various options, sizes and prices.

If you don’t know how to select the right size and kind of solar panels right for your needs, then keep reading.

After reading our article, you will find out that providing your campsite with much-needed power is a lot simpler and affordable than you thought. There is no excuse for running out of power in the bush!

The basics

First, we will outline the basics behind what to look for and how to make sure you have enough solar to cover all your 12v needs, without spending too much.

Let’s get some terminology clear.  DC power is what you get from your 12v battery in your vehicle/caravan.  AC power is what a powerpoint at home or a 12v/240v inverter gives you.

When calculating solar panel sizes, you have 3 things to be aware of.  Watts, amps and volts. Their correlation is shown below.

Power (Watts) = Voltage (Volts) x Current (Amperes)

Now, we are going to break down the 5 most important things to check for when you are shopping for a camping solar panel;

1. CELL TYPE

When assessing the possible performance, quality and value of a solar panel, there are a handful of factors that affect the output that is possible for a given size of the panel. With modern technology, there are 2 main competing styles of photovoltaic cell used in the production of camping solar panels.

• Polycrystalline cell: These are the initial style of solar panel available on the mass market and were developed to be much more cost-effective to manufacture, using a lesser grade of silicone material, whilst still outputting sufficient useful power for campsite usage.
• Monocrystalline cell: Since the availability of higher grade silicone has become much more affordable, the ease of manufacture of higher performance solar panels means the surface area of a photovoltaic cell allows the size of camping solar panels to be much smaller than the styles previously available without increasing the cost, or size, means that it is now possible to power a whole campsite off one simple panel design

See below the visual differences between those two kinds.

 2. WATTAGE OUTPUT

The output of a solar panel is calculated into watts - the measure of total power. Again, the wattage of a solar panel is calculated with the formula below.

Power (Watts) = Voltage (Volts) x Current (Amperes)

The wattage of a solar panel is calculated using the unregulated circuit voltage and the total possible amperage output. Taking an example, below is the power calculator for a typical 250W solar panel.

13.8 Amps x 18.2 Volts = 250.068 Watts

This means your solar regulator has a total of 250 Watts of power to play with to keep your battery topped up and your campsite appliances running.

 3.SOLAR REGULATOR

As mentioned above, the voltage output of a typical 250w solar panel is 18.2 volts

 A 12v system is usually floating around 12.8 volts and a healthy charging voltage floats around 13.8 – 14 volts

This means that you have an excess voltage of around 4.2 volts, that needs to be reduced to prevent the dangerous “overcharging” which can release dangerous Hydrogen gas, and boil the acid inside your 12v batteries

There are 2 main types of voltage regulation circuits commonly in use today, that adjust the output voltage to a healthy level for your vehicles battery setup.

• PWM: PWM (Pulse Width Modulator) solar voltage regulators emit constantly varying pulses of DC power of varying durations to control the current flowing into a battery, and efficiently provide the most available power to a battery system. PWM regulators are one of the most popular styles of voltage regulation and are one of the most commonly included voltage regulators on many modern solar panel systems.
• MPPT: Maximum Power Point Tracking(MPPT), is an up and coming addition to the solar voltage regulator arsenal. The MPPT Regulators are considered cutting edge when it comes to extracting maximum potential wattage from a photovoltaic cell. The MPPT regulators monitor the output voltage of the solar cell, and the ability of your battery to take a charge, and converts the output to the maximum potential current, to increase the speed of charge and efficiency of your solar panel. The MPPT style voltage regulators can improve performance by up to 30% during overcast days but it can also cost twice as much a PWM regulator. 

4. SOLAR PANEL TYPE

There are two main options: portable or fixed solar panels. The portable type will subdivide into blankets, flexible or folding solar panels.

• Flexible solar panels are made by depositing PV material on flexible substrates like paper, making the most lightweight solution. They are the ideal choice for low-load bearing roofs, a popular use on boats and yachts. Due to their flexible nature, they can fit on curved and other complex surfaces. 
• Folding solar panels are a brilliant option if you’re on a budget and aren’t looking to travel regularly. They can be heavier and bulkier than their counterparts, but if you’re only away for a week and taking just the essentials with you, that shouldn’t be an issue. A big advantage of portable solar panels, like solar blankets, is that they are easy to set-up and angle to chase the sun. They quite often come with the solar controller and cables to plug to your battery, making this a no-fuss solution!
• Fixed solar panels are great if you just want to set and forget. They are attached to your vehicle, so you can charge while on the road and while parked at your campsite. On the flip side, solar panels must be in direct sunlight to get the best results – which isn’t always possible in campsites.
• Solar Blankets: For frequent travellers concerned about space and weight, solar blankets are a good investment. While more expensive than glass solar panels, they offer excellent quality and durability. Convenience is the best thing about solar blankets; you can set it up anywhere –  hang it off your awning, drape it over your trailer or bonnet, and start catching those rays. You can even place them across the windscreen so they keep your car cool while collecting amps! Then when it’s time to move on, fold your blanket away and slot it into your car. Easy!

No matter your preference, OnTrack Outdoor has all solutions available. You can shop for solar panels here.

5. CAMPSITE POWER USAGE

When choosing a camping solar panel setup, you need to consider your average power consumption at camp. By calculating your average amperage usage per hour of all of your camping accessories, you can figure out your usual amp hour requirements.

With these figures, we need our solar panel system to generate approximately 50amp hours of charge, So when looking at a 120w Solar Blanket, you have minimum daylight of 9 hours with a maximum charge potential of 7.41 Amps resulting in up to 66.69 amp-hours of charge. Making it perfect for this simple camping solar setup!

Armed with this knowledge you should be able to select the perfect 12v portable solar panel setup for your setup, whether it's weekend trips away, or school holiday breaks!

Click here to see our full collection of solar panels and accessories!