Portable vs Fixed solar panels off-road

What is the best solar panel is suitable for camping?

Do you need help deciding between a fixed solar set up vs portable folding solar panels?

Home of 12 Volt offer a huge range of both portable and fixed mount solar panels to suit the Caravan and camping market and it's all quality!

So let's explain the difference:

 

Mounting solar panels to the roof of a Caravan

There are a number of reasons you may choose to fix your solar panels on the roof of a caravan. From ease of use, no set up and pack up, storage issues and just overall convenience; there is no wonder this has been a popular option for campers for the past 20+ years. 

Mounting solar to the roof is a fantastic option for individuals looking to stay independent of 240 volt power. Solar panels have the ability to harness power from the sun and store it back into a battery storage system. The ability to harness free solar power can help an individual to stay in one location for extended periods of time, if not, indefinitely.

So how much solar do you need and what type of panel should you use on the roof?

How many solar panels do I need to charge my battery? This is a common question we are asked and honestly, it comes down to a number of factors. Factors such as:

- How large is your initial battery set up

- How long are you looking to stay independent from power

- What are you running from your battery system

- Are you charging from any other source (Vehicle / Generator, etc)

Solar is only one clog in the entire off grid system and when coupled with other forms of charging, it can be extremely useful in an entire off grid set up. 

Taking into consideration the above factors, let's start breaking it down.

The majority of travelers will start with one battery, around a 100 AH or 120 AH size. The battery has the ability to provide you an initial amount of time off-grid on it's own, before adding any form of charging.

The average caravan user will draw approx 20 - 50 Amps per day from the battery system. This essentially means that one battery can provide the camper a 2-3 days of independent use on the battery alone, before adding solar.

Now, no matter what a sales person may tell you, a solar panel will only operate in sunlight. Solar Panels require ultra violet light in order to produce power, which essentially means that you can apply he same rule as 'any time you can be burnt by the sun, then at this same time, a solar panel will work in these conditions too'. Solar will therefore operate in overcast conditions, however, they will not operate in the shade.

Throughout Australia, the sun will remain in the sky for differing times of the day; the Western and Northern parts of Australia will see much longer days compared to the Southern or Eastern parts of Australia.

Let's say the average time we can harness the sun light for is approx 8 - 10 days o any given day. This time frame is what we work with in order to work out how much power we can harness from the panels.

But what if we are mounting flat to a roof of a Caravan or Motorhome? Then what? .. Well, it is simple, mounting flat to a roof of a vehicle will mean that we limit the amount of time we would be harnessing the power from the sun, and therefore instead of working with a 10 hour time frame, we instead say that we have the ability to harness on average 6 hours per day of sunlight.

Each panel has the ability to produce a differing amount of power per every hour in the sun. The average size panel that campers tend to install are between 100 - 150 watts in size. Let's say we work with a 135 watt monocrystalline solar panel, the average output of this size panel would be approx 7 Amps per every hour in the sun. (7 Amps x 6hours = 42 Amps produced in one day). *variables apply

When mounting on the roof, many users decide to mount multiple solar panels, linking them in parallel to harness twice the amount of power. (2x7Amps = 14Amps x 6hours = 84 Amps produced in one day) *variables apply

So what if you are only drawing 50 Amps but you can produce 80+ Amps from the solar panel? This is no problem at all! Providing your solar panels use a solar charge controller, otherwise known as a solar regulator, then this will ensure that the batteries are never overcharged, even if the battery reaches fully charged half way through the day. The solar regulator will limit the load into the battery and will provide only what the battery requires.

At the end of the day, the most important thing to know is how much power you are using from the battery system verses how much you can replenish back into the battery system. 

 

But the big question that many remote campers fail to ask themselves is..

How often will you park in full sun vs parking in the shade?

Combating heat whilst camping is a huge factor that many individuals face. It is not surprising that when setting up, it is common for campers to look for a beautiful shady tree to park their vehicle under in order to stay cool from the suns rays. But what does this mean for your solar panel output? Well, as stated above, no panel can operate in the shade. The panel will produce voltage in the shade, but will not produce amps. Unfortunately it is the AMPS that charge the battery.

So what if you want to park in the shade?

No problem, the best alternative to this would be the choice of a portable solar panel instead of a fixed mount system.

Portable solar panels allow the user to park the vehicle in the shade, whilst still being able to harness the sun's power. Simply place the solar panel in sun and run a lead from the solar panel to your battery set up.

Many portable panels are built with in line solar charge controllers, however, you may choose to opt for a solar panel with no regulator in line if you instead have a regulator in your system. *Note: You must use a solar charge controller / regulator between the battery and the solar panel to ensure that overcharging does not occur.

When choosing to opt for a portable panel, there are a number of other advantages in which the user will not get from the use of a fixed mount system.

Portable solar panels allow the user to essentially 'chase' the sun throughout the entire day. This can extend the average 6 hour harness time to 10 - 12 hours in some cases! This means that a portable panel can sometimes provide to be twice as efficient compared to a fixed mount system.

Of course there are downsides of a portable panel. The need to carry additional items in the vehicle can prove difficult and also the act of setting up, moving and packing up the panel can become quite tiresome.

If you were to ask us on what our opinion on the best set up is, we would have to say that every individual's system is very different to the next... however, we do strongly feel that a portable panel is very big advantage to hold, even for users of fixed mount systems.

We'll leave you with the last say as to what system suits you best ..

If you do need help in calculating your system and how much solar you need, please check out our DIY calculation page HERE

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