Powering your auxiliary batteries with portable solar panels has been something that many campers have known about for a while now. Here at REDARC, it has been extensively covered. From why it’s good, to why you should, we have demonstrated how you can get the most of your solar setup.
But what’s less understood, is knowing how much solar you need for your set-up. In this blog, we break down what you need to know to get started and introduce the REDARC solar calculator, so you can finally stop asking that question, 'how much solar do I need for camping?"
How much solar do I need for camping - getting started
You're probably asking yourself, 'what size solar system do I need?' There's no hard and fast answer to this question. No two set-ups are the same and your needs are going to differ from your neighbours either side of you. Plus, with so many different sized panels available on the marketplace, it can get pretty overwhelming where to begin.
The first thing you need to know is that all electric devices, like your fridge, lights, and charging equipment, are measured in Amps. Amps is a measure of how fast an electric current flows. The bigger the current, the more electricity is flowing.
So, you need to figure out how many electrical loads you have or will have and how many amps they will draw from your battery. This information can be found in the product manual or on the label of every device.
Next, you need to determine how long you will be using each item over a 24-hour period, as this will give you the total Amp hours used per day. Amp hours (Ah) is a measure of stored power. Amp hours is the number of Amps drawn, for the amount of time in hours that you draw that current.
Amps x hours = Ah
So, you need to know three things:
- The number of electrical loads to be run and their amps
- The duration of each item to be run over a 24-hour period
- The size of your battery
Therefore, the number of solar panels you require will be determined by the amount of charge that needs to be returned to the batteries during the sunlight hours of each day.
How many solar panels do I need?
To answer the question, how much solar do I need for camping, it is best to compare solar panels by their power rating or wattage. Watts is the basic unit of power and is a measure of how much electricity it can provide. In other words, the wattage of a solar panel determines the rate at which you can deliver to charge the batteries.
Volts x Amps = Watts
Say for example, you have a 12v system and you need to replace 75A/h of charge back into your batteries each day. You have 6 hours of sunlight each day. You will need:
75Ah x 12V = 900Wh
900Wh/ 6h = 150W of solar panels
In reality, it is recommended that you always overrate your requirements by at least 20%, therefore you would need 180W of solar panels.
As part of your solar panel system, it is also recommended you invest in a solar regulator to ensure your solar panels are applying safe and efficient charge. Browse our advanced range of solar regulators now for more information.
A real life example
Let’s run a scenario to gain a better understanding.
I go camping with the above equipment. The total loads used per day is 67Ah, therefore this needs to be put back into the battery each day. In order to maximise efficiency and extend the life of a battery, it is recommended that the battery is only discharged to no more than 50%. Therefore, I would need around a 134Ah battery.
Let's assume I only get 6 hours of optimal sunlight each day. So, how much solar do I need for camping?
67Ah x 12V = 804Wh
(804Wh/6h) = 134W of solar power
Including an additional 20% it comes to 161W of solar power.
This could be a combination of a 150 watt fixed solar panel, and then a solar blanket, or a 150 watt fixed solar panel and a 120 watt portable solar panel.
It’s not uncommon these days to see 4WD’s with a fixed 150W solar panel and an additional solar panel or solar blanket to provide more sustainable power when using more devices/appliances at camp.
Generally speaking and providing the weather conditions are suitable (not overcast), a 150W solar panel when paired with an in-vehicle battery charger will allow 24/7 use of a modern 60L fridge.
REDARC Solar Calculator
Although the concept can be quite technical, once you get your head around the calculations and different scenarios, you will find it’s not that complicated at all. All it requires is just a bit of your time to sit down with a pen and paper to work it all out.
But we’ve made it simple. Our solar calculator does all the work for you and provides an indicative measure of how much power will be needed per day depending on the size of the auxiliary battery bank and appliances used whilst touring.
To use the REDARC solar calculator, click on the button below.
Now you know how to answer the question, how much solar do I need for camping. You can find out more about the different types of solar panels on our website.
For a brief introduction to monocrystalline vs polycrystalline solar panels, click the link (left). And for those looking for a bit more of a detailed explanation, try our mono vs poly solar panels page.
