Fixed Solar Panel Comparison & Guide

 

G’day.

This post is a fixed solar panel comparison, comparing solar panels that get semi-permanently mounted to a vehicle and are for 12 volts systems.

There are a lot of options when looking at solar panels, so this post will consist of fixed solar panels, while there will also be posts covering:

As the top portion of the fixed solar panel comparison post is just general solar panel information, you will find that it is the same across all three posts, so feel free to skip it on the other posts.

In the fixed solar panel comparison post you will see the pros and cons of this particular choice of system, be sure to check out the other posts for their pros and cons.

To make the fixed solar panel comparison easier for the reader, the tables provided will be sortable so you can organise the data as you see fit. The table of contents is also clickable so you can skip to the desired section.

The fixed solar panel comparison scatter plots are an interesting visual aid but should not be taken too seriously as a buying guide.

Often things such as weight, quality and dimensions will be the defining factor in what panel you end up looking at, although price is also important.

 

12 Volt system comparisons

For those who don’t know about 12 volt systems, I have written a very detailed post about how to plan a 12 volt setup that includes all of the information you could possibly need.

*Disclaimer

Affiliate links may be present on this page. These are links to websites such as Amazon, where if you decide to purchase something, then they will offer me a tiny commission. This comes at no extra cost to you and is just a way for me to try and support myself and the blog.

Why I did the fixed solar panel comparison?

 

As someone who is currently in the process of a 4WD build, this was my own research that was going on for my benefit in the background, but it would be a waste not to share it with others.

The idea at this stage is to mount a fixed solar panel on top of my canopy. Your available roof real estate will be a determining factor for the fixed solar panels.

The size of your lithium battery would also play a large part in determining how much solar you might be interested in, check out my lithium battery comparison here.

As far as sizing is concerned, I don’t really know what I am after, but given that I have a 125Ah battery at this stage, I will have a fixed solar panel system of 200W or less.

Therefore the systems here won’t be any larger than 200W and no smaller than 100W.

 

 

What brands are included in the solar panel comparison?

The brands that you will see in this post are listed in no particular order below, click their titles to be taken to the solar panel section of the respective websites.

Being in Australia, these brands were selected for the solar panel comparison based on availability to me here.

 

Redarc

Often referred to as the cream of the crop in 12 volt systems here in Australia, Redarc have a great track record when it comes to being bullet proof as well as innovative.

 

Enerdrive

Very much the most popular brand out there, a good mixture of quality without the high prices, although nor is it cheap by any means.

 

Kings

Kings are a budget brand that sell out of 4WD Supacentre stores across the country.

A good brand for those looking to make their first purchases without breaking the bank.

 

Victron

Internationally known company that have a large history in the renewable energy sector, big in marine and they offer very high quality equipment.

 

KT Cables

I have to admit I don’t know a lot about these guys but they are an Australian company that appear to be good quality and have some innovative products.

 

Projecta

A popular company here in Australia that is found at Supercheapauto and Repco. This makes it one of the most available brands on the market and easy to find to view in person.

A brief rundown on solar panels

 

When it comes to solar panel comparisons, it can get quite confusing.

The three types of solar are fixed, portable and blankets. You can combine all three of these if you wish to boost your system’s power by paralleling the panels.

This post is about fixed solar panels, but there are posts for the other two types as well. Just so everyone is on the same page here is a very brief explanation of the different types available.

FIXED
These are the panels that will be permanently mounted to a roof, canopy, caravan etc. They can be removed but are not getting packed away daily as they are bolted down.

BLANKETS
The blankets are the most technologically advanced, it will fold multiple times and pack away very small to take up a tiny footprint. They offer the best performance when looking at their weight against output.

PORTABLE
The portable panels are like the fixed panels, but they fold in half and get packed away when not in use, they come with legs to angle them towards the sun and get the maximum efficiency from your system.

 

 

Why you should consider getting a solar panel

 

If you want to set up camp for a few days and don’t think that you’ll be driving around, then solar is really important to top up your batteries.

Solar can allow you to run a smaller battery capacity in some instances as you know it will get refilled to some degree, so you don’t need a bucket load of amp hours to get you through an extended stay somewhere.

The way people travel these days with the amount of technology that needs a recharge, a solar panel will help you go further and maintain creature comforts. A panel is good clean energy and the system can be built up to the appropriate size over time.

Output amperage vs. Input amerage

 

Some manufacturers will advertise the output of the panel, others the theoretical input into a 12 volt system. In the solar comparison tables below I have added a column for both of these values.

Let’s do a little bit of simple math to get started, who doesn’t love math?

Solar panels often operate on a voltage of 17-19 volts, this gives them headroom to provide enough voltage to charge a battery in poor conditions: late afternoon, overcast, shade covered, or very hot days where resistance increases etc.

In these poorer conditions the voltage is hopefully above 14 volts and can charge a lithium battery. When conditions are good, this means that your solar regulator can input a higher amperage into the battery than that being measured at the solar panel.

This is because of a variant of ohm’s law: Power = Current x Voltage.

Therefore: Current = Power ➗ Voltage

The “power” of the solar panel is fixed, for example 100W of power. Your solar panel does not get hooked up directly to a battery, it goes through a regulator first (DCDC chargers often have built in solar capabilities).

A regulator will be outputting 12 volt** to the battery, this means that the current will be higher to compensate for the lower “voltage” of the equation, keeping the maths correct.

Simple theoretical example for a 100 watt panel with 20 volts max output:

100W =  20 Volts x Current

Therefore current = 5 amps.

 

MPPT regulator transforms voltage to 12V**

Current = 100W ➗ 12

Current = 8.333 Amps into battery.

 

**it’s not actually 12 volt, it is higher, but for the purpose of the theoretical maths in the tables I just used 12, because of the naming scheme “12 volt systems” etc.

Voltage Open Circuit

 

Voltage open circuit is not listed in the tables below as all of these panels listed are in the 20-23 VOC range.

BUT it should be noted that you can’t use just any panel on your 12 volt system!

The panels are especially made for this type of activity, they are different to the panels found on houses for example. Where the VOC becomes relevant is making sure your solar regulator can handle the panel’s VOC.

Solar panel accessories

 

Please note that you cannot hook a battery directly to solar power.

The voltages are too high and they need to be regulated, so they need to go through a regulator. Most DCDC chargers these days offer solar input built in, so be sure to buy a DCDC charger to suit.

See what the maximum power of each regulator or DCDC charger is so you don’t overload your system.

When it comes to solar regulators there are 2 types: PWM and MPPT.

Without going into details, MPPT is the option that will get you more power from your solar panel system and is the preferred method of regulation.

MPPT regulators will give anywhere from 20-30% more power back to the battery depending on the conditions.

Can you combine solar panels?

 

Yes, you can combine solar panels, provided you know about how you are connecting them.

You want to combine the solar panels in parallel to boost your wattage, the solar regulator will be the limiting factor so make sure you are aware of what it can and can’t handle.

Do not connect your solar panels in series as this will add the voltages together and you will more than likely ruin the solar regulator, or it will auto shut off.

People can and do connect in series, but I don’t think those people will be confused about why they do it, so for the purpose of most people, it is always in parallel.

Combining solar panels is a very popular thing to do provided you have the space and budget, as it allows you to combine the advantages of each system, which will be discussed further down in the solar panel comparison.

You forgot about [insert brand here]!?

 

Look, I am sure I missed out a few brands but these are the brands that were readily available for me to buy and look at, therefore the easiest to research and compare.

No further brands will be added to the tables but feel free to use the tables to make your own solar comparison and find the best product for you in your region. I hope it helps in some way.

 

Fixed Solar Panels

 

Fixed solar panels are the type that get mounted to a canopy or on top of a roof and stay there until they get damaged or upgraded.

These types of panels are the cheapest per watt and are therefore a great starting point for people who want to recharge their batteries when they’re in camp and not driving.

Avg $/Watt = 1.71

Avg Watts/kg = 15.38

In comparison, portable panels:

Avg $/Watt = 3.34

Avg Watts/kg = 11.62

 

Solar blankets:

Avg $/Watt = 4.09

Avg Watts/kg = 29.16

 

As you can see the fixed solar panel is by far the cheapest when you talk about dollars spent per watt of power.

Who are fixed solar panels for?

 

Fixed solar panels are for those who want a constant charge to their batteries and are happy to dedicate the roof space as a power generating area rather than a storage area.

They are great for those who have dedicated 4WD touring vehicles, that don’t need to do double time as a family vehicle for example. Also brilliant on camper trailers and caravans.

A dedicated 4WD tourer will be able to allocate this roof space for this purpose and still have storage space elsewhere.

 

Fixed solar panel pros

 

  1. The fixed solar panel is great because it is constantly working, there is no setting it up or tearing it down, you don’t need to change its angle (generally speaking) and you never forget to bring it with you.
  2. If you pair it with the right DCDC charger it will also charge your batteries as a priority over the alternator while you’re driving along. So it works quietly away in the background.
  3. The fixed solar panel is the cheapest type of solar panel and is usually lighter than a portable panel of the same output.
  4. If you park your 4WD outside at home, your battery will be charged all the time and you won’t need to worry about charging it before a trip.
  5. You also could argue that fitting solar on the roof will help prevent you from overloading the roof of your vehicle. It could force you to pack smarter and bring less unnecessary things.

 

Fixed solar panel cons

 

  1. The panel must go where the car goes, therefore in camp if you park in the shade like most people tend to do, you lose solar performance.
  2. This also means that the solar panel can’t be angled towards the sun (although you can get brackets for this). Generally speaking though the panel is flat, which is great at midday but loses some performance in the afternoon and morning.
  3. If you want to store things on your roof, you will either need to remove the panel or cover it up, rendering it useless. For example if the vehicle doubles as a work car during the week and you need to put materials on the roof.
  4. There is also potential for it to be damaged on the roof from hail or tree branches etc.
  5. If someone was brazen enough and your car was parked outside, there is a minuscule chance it could be nicked, but I would imagine that is unlikely.

Pricing

 

Wherever possible the pricing used was from the manufacturers’ websites. This was done regardless of if there was a sale on at the time of the table being made.

However the opposite may occur and prices may also go up after the making of this table, so understand that everything is fluid and forever changing.

Clicking the solar panel tag under “brand” will take you to see the latest pricing on Amazon or eBay, these are affiliate links but they don’t cost you any extra (as described below the intro).

Clicking the “price” will take you to the product on mygenerator.com.au

To see what other fixed solar panels are available at mygenerator.com.au that didn’t make the cut here, click to be taken to the relevant page. The website often has bundle deals if you’re after more than one panel.

Fixed Solar Panel Comparison Table

 

I have set the lower limit to 100 watts here as I think anything below that borders on pointless and didn’t manage to pique my interest.

If you have really limited roof space though just know that smaller panels do exist, so search around.

BRANDWATTSCOSTWEIGHT (kg)$ / WW/kgWxLxD (OPEN)MAX VOLTAGEMAX CURRENT AMPSTHEORETICAL AMPS INTO 12V BATTERYWARRANTY
ENERDRIVE100$2458.12.4512.351195x541x3518.75.3508.335
KINGS110$1007.390.9114.881005x670x3518.26.0409.161
VICTRON115$19781.7114.371015x668x30196.0409.58
KT120$1956.91.6317.39945x640x35196.32101
PROJECTA120$239101.99121570x511x3517.56.86101
REDARC120$2737.51.7021.331005x670x35206102
PROJECTA135$249111.8412.271360x665x3517.57.7111.251
VICTRON140$20791.4815.551250x668x30197.3611.66
ENERDRIVE150$31011.52.0613.041210x808x3518.58.1112.55
PROJECTA160$295121.8413.331490x165x3517.59.1413.331
KINGS160$13090.8117.771190x770x3019.58.213.331
VICTRON175$240111.3715.911485x668x3019.49.0314.58
REDARC180$40610.72.2516.821475x670x35209152
ENERDRIVE180$29911.51.6615.651482x680x3519.89.1155
REDARC200$44212.52.21161110x992x35201016.662
KT200$27911.51.3917.391476x670x3519.610.216.661

Fixed solar panel comparison scatter plot

Below is the fixed solar panel comparison scatter plot, this might help you decide between two panels that you hadn’t really been able to split before, or help you rule out a panel that you think represents bad value. 

Fixed solar panel comparison thoughts

 

When I look at that scatter plot it seems to me that the Enerdrive 100 definitely won’t be my choice. Unless those particular dimensions are of importance to you, it is hard to make an argument for it.

It is pricey per watt and also not overly light for a small 100W panel.

Redarc’s 120W panel looks like a much better option if you were going for a small panel for only an extra $28 you get better performance and less weight.

For the larger end of the panels, the Victron 175 looks to be just slightly better than the Enerdrive 180, as is the KT 200.

Fixed Solar Panel Comparison – Things To Consider

 

There are a few things to consider when looking at this data. Things that could shape the way you decide to go with your purchase.

 

Unified system

You may already have an Enerdrive system, or Redarc, or Kings.

Sometimes it is easier to keep the whole 12 volt system identical so you know that it will all just work!

Brand reputation

You may also decide to avoid a budget brand, despite what appears on the scatter plot.

To be honest, I don’t blame you. Reputation goes a long way and reliability can be key. However, for those weekenders and casual users there are great bargains to be had amongst the budget offerings.

 

Warranty

Look at Enerdrive’s 5 year warranty…

That might be hard to pass up and the more you use the system the more likely it is that the warranty will be of use to you. Be sure to read all the terms of the warranty first though as there may be some disclaimers involved in that.

 

Roof space

Sometimes as luck has it, a certain panel fits perfectly on your roof and fits your future plans for that space to a tee!

Perhaps a panel is small enough to only take up a part of the roof, or completely fill the empty roof space and provide way more power.

In these scenarios I wouldn’t be passing up the perfect fit to try and save a few pennies, it will definitely pay off in other ways for the time that it is mounted.

Which fixed solar panel did I end up choosing?

 

I have not chosen yet.

I am considering the Enerdrive 150 watt panel as it is a squat panel and there is a possibility I could start with one panel and fit another one later if I felt the need, giving me 300W total.

The other thing I am considering is just going for one panel, possibly the Victron 175W, Enerdrive 180W (the warranty is good) or the Redarc 180W.

After I have made a purchase or fitted the panel(s) I will be sure to update this part of the post.

Fixed solar panel comparison – Final thoughts

 

I hope this has been of some help, if for nothing more than to get you thinking.

If you can think of anything else that needs to be discussed feel free to comment, but I won’t be adding any more panels to the comparison as I have redone this table about 3 times as I kept considering more and more options.

Now you can critique your panel of choice if it isn’t presented here and compare it against the panels that are.

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