One of the most crucial parts of planning a camping, 4WD or caravan trip is deciding how to power your technology. If you’re going to enjoy the great outdoors, you may as well take advantage of the natural energy solution on offer: solar power. With a well-thought-out approach, you’ll be able to charge your smartphone, power a 12-volt fridge and even a 240-volt hair dryer or air conditioner. In this guide, we look at camping solar panels and how they can be used to recharge your batteries to power your outdoor adventure.
Why do I need camping solar panels?
A battery, whether in your tablet, car, or a dedicated caravan battery system, only has so much capacity. What are your options if you don’t have access to mains power? If you have a car, you can pull power from the cigarette lighter or USB socket whilst running the vehicle. We don’t recommend pulling power from a car battery if the engine is off. Especially if you’re in a remote location, the last thing you want is a flat car battery. Instead, you should opt for an independent source of electricity to power your camping needs.
Portable power stations offer a reliable and independent source of power. Devices such as Bluetti’s EB3A, AC180, and AC200Max are just some of the portable energy sources you can use to power your campsite. Even better, you can recharge compatible portable power stations by using camping solar panels, giving you an ongoing pool of power to draw from.
It is actually possible to power a device straight from a solar panel. For best performance, however, you need a battery to store and regulate the power. For example, cloudy skies can lead to inconsistent power output, which is why it’s best to let a portable power station use solar energy to charge, and then connect devices directly to the station.
How do solar panels convert sunlight into electricity?
A solar panel converts sunlight into electricity using photovoltaic (PV) cells. PV cells are made of materials that generate electrons when exposed to light. Solar panels generate electricity when particles of sunlight knock electrons free from atoms, setting them in motion. This flow of electrons is electricity, and solar panels are designed to capture this flow, turning it into a usable electric current.
Panels are rated by the maximum power they can produce. For example, a 100-watt panel will produce up to 100W in full sun in optimum conditions. If you had a 1000Wh battery (12v -83Ah) that was 50% full, it would need a minimum of 500Wh to recharge. The panel delivering 100W for an hour provides 100Wh, so in theory 5 hours to replenish your battery. Considering real-world conditions and losses as part of the solution, you probably need more than 8 hours to bring your battery back to full.
In addition to this guide on camping solar panels, we’ll also have guides that detail power consumption and the best batteries to use.
What types of solar panels are available?
There are three main types of solar panels: monocrystalline, polycrystalline, and thin film. Each type has its own advantages and disadvantages. The best solar panel for your installation will depend on your preferences and factors specific to your needs.
Monocrystalline solar panels are made from a single crystal of silicon. They are the most efficient and longest-lasting type of solar panel. They are also the most expensive.
Polycrystalline solar panels are made from multiple crystals of silicon. They are less efficient than monocrystalline panels but are more affordable.
Thin-film solar panels are made by depositing a thin layer of photovoltaic material onto a substrate. They are less efficient than crystalline silicon panels but can be made flexible and lightweight.
A less efficient panel means more panel surface area is needed to generate the same power wattage output. Solar cells can be packaged in a fixed glass panel aluminium walled enclosure or a flexible film.
Advantages of fixed panels:
It can have a high-voltage output
Generally, have better efficiency
Fit and forget
Advantages of flexible/portable panels:
Flexible can be bent slightly to suit a curved surface
Portable can be easily moved to maximise rays from the sun
There are also portable solar panels suited for camping that can be folded and stored in a vehicle and set up whilst you are stationary. Flexible, portable panels, often called solar blankets, are mostly not weatherproof, so they need to be packed up and protected from rain.
A house solar panel will have a higher voltage output versus a 12-volt specific solar camping panel.
How do I make the most of my solar panels?
The type of panel you buy is the starting point for getting the most out of your solar panel. Chances are you are limited in space. This may be a backpack or the roof of a caravan. Panels are of different quality and different prices.
A panel’s efficiency, normally around 22%, indicates how efficiently the panel is converting the sun’s energy into electricity based on a set area. This higher efficiency is important if you have limited space, like an RV roof.
Don’t shade solar panels!
Panels do not like being partly shaded, like shade from a tree branch. This shade affects the area more than the cells shaded on the panel, meaning you will get minimum power output. We used a Bluetti PV200 Solar panel (200w) and a 425-watt house panel for our testing.
Both panels are monocrystalline and have MC4 connectors (industry-standard solar connectors). The fixed panels are waterproof, weigh 20kg and measure 1.9 x 1 metre. The Bluetti is water resistant and weighs 7.3kg and 0.6 x 2.3m (0.6 x 0.6 folded)
Using the house panel in winter sunlight, we measured an output of 283 watts. When I placed my hand on the panel, essentially only shading a fraction of the panel, the output dropped to 63 watts, a 75% drop in output. Shade is your enemy. Panels with “half-cell” technology better deal with shading.
The same test using the Bluetti portable panel had very different results as it is made up of four panels, meaning shade on one of the four panels does not affect the output of the other three panels, so the loss is lower. Our equivalent tests saw a 5% to 30% loss depending on how much you shaded.
The direction of Solar Panel
The sun is hottest in summer in the middle of the day. To a point, this also means that a panel can generate the most electricity in summer. However, a panel tends to lose efficiency the hotter it gets.
Using the Bluetti panel in Sydney in mid-May at 1 pm, we generated 155W (from a 200W panel). In full sun at 2:30 pm this dropped to 115W. In overcast conditions at a similar time, the output was 58 watts. We could not test in the rain as the Bluetti panel is not waterproof, only water resistant.
A fixed panel does not move, but its angle to the sun affects the output. The best angle changes depending on where you are located in Australia, north to south and the time of year due to the sun’s angle. There are many complicated formulas to determine this. Still, chances are your fixed panel is flat on the roof of your car or caravan.
The effects of angle can be seen in this video, where a flat fixed panel produces 211 watts, which increases by roughly 50% to 330W when lifted at an angle.
A benefit of the Bluetti portable panel is that it can be laid flat or at an angle. Its rear adjustable legs let you position the panel at 40, 45 or 50-degree angles to maximise output. Australia is in the southern hemisphere, so we want to orient our panels north. You can also move and adjust the Bluetti panel during the day to maximise solar input and voltage output.
It’s important to make these adjustments so the panel follows the sun’s position during the day. For example, turn the panels to the northeast in the morning to follow the sunrise, north at noon and northwest in the afternoon to maximise the output. Testing these orientations, I saw a 29% output improvement by orientating the panel 45 degrees on the horizontal plane (east or west movement).
Using the vertically adjustable snaplocks on the rear of the Bluetti solar camping panel, I got 102 watts at flat or zero degrees, 155 watts at 40 deg, 163 watts at 45 deg and 161 watts at 50 deg. The biggest gain was 62% which compares back to our fixed panel test of 50% gain.
The net effect is the better you can align your panels to the sun, the faster you will charge your batteries.
Connecting your solar panels
A voltage regulator is required to get power from a panel into a battery. This voltage regulator may be a separate device or built into a charging solution. You must not use two voltage regulators.
Your battery solution will only accept a certain voltage, so your panels must not exceed this voltage. A distinct advantage of transporting power at a higher direct current (DC) thru a cable as less voltage is lost between the batteries and the solar panel. A house solar panel could have a voltage output of 35 volts. If you had a Bluetti AC200Max portable power station, you could connect this panel as the AC200Max supports a voltage range of 10 volts to 145 volts. A custom 12-volt in-car solution may be limited to 19 volts, so you could only use a panel with up to a 19-volt output.
Getting the power from the solar panel back to a battery then requires cables. The length and thickness of cables will affect the loss of voltage. Longer, thinner cables will experience more voltage loss, causing less power to get to the battery.
Two or more camping solar panels can be connected in a parallel or serial connection. A positive and negative cable comes out of each panel. Panels would be serial if the panels were connected by connecting one panel positive to the other negative or vice versa. Parallel would utilise a plug allowing two or more positives to be connected. Which method you use depends on what voltage your battery solution can accept. A serial connection of two like panels will double the wattage, and amps will remain the same. Two like panels in parallel will double the amperage, and the voltage will remain the same. E.g. The Bluetti panel we tested has a maximum power voltage of 20.5V at 10.3 amps, so 2 x PV200 in serial would produce up to 41 volts at 10.3 amps or 20.5 volts at 20.6 amps in parallel.
Do not exceed the voltage or the maximum amperage your solution can support. Best to seek professional help or a prepackaged solar generator solution when deciding on your setup.
A valuable solar camping panel not bolted down or locked is easy to steal, so be aware if you will leave it unattended at camp all day.
Be careful of cheap eBay panels offering high wattage for a relatively small size. If it seems too good a deal, it probably is not.
Main things to remember
So many variables affect how much power a solar panel can produce. It is hard to recommend a type, let alone a brand due to how quickly solar technology advances.
If you have the space and can hard mount a panel and want to set and forget, I would buy a house panel. There are lots of second-hand panels available for a small outlay.
If you are on a travelling adventure, I would recommend something like a Bluetti foldable solution, where you can follow the sun and maximise your output. The Bluetti 200W panel sells for $700 and has a 1-year warranty.
Orientation towards the sun on both the vertical and horizontal plane will give you the highest wattage output. This output is likely to be less than the stated rating.
Assuming your battery is right-sized for your power needs, the rule of thumb is a 12-volt 100amp (1200W) battery will need 200 watts of solar to charge it. Keep all of these things in mind and you ought to get the most out of your camping solar panels.