Solar is a relatively new topic.
After all, at the age of three, my father installed four massive solar panels on my childhood home back in the early 80s. Heck, he was quite progressive! While solar panels are not new themselves, using solar panels on travel trailers is – and it’s changing the way we live and travel.
A properly designed solar system is not a simple “one and done” solution. I’ve seen countless manufacturers put one or two solar panels on the roof of their RV and call it “solar-powered.” The unfortunate reality is this could not be further from the truth.
There are so many industry buzzwords floating around that it can be quite challenging to understand what solar means. My goal is to explain what it means to have solar power and what you can expect to gain from a properly designed solar system. After all, how does a solar-powered travel trailer benefit me?
I’ve broken it down into three straightforward concepts to help understand exactly what solar power does and how it benefits the travel trailer owner’s day-to-day life.
The top three considerations for finding the best solar powered travel trailer while traveling off-grid are:
As an architect, when designing a solar-powered brick and mortar home, the location and orientation of the solar panels with relation to the sun are critical to maximizing the capture of energy. In the northern hemisphere, a north-facing wall or roof surface will receive very little if any sun exposure at all when the foundation is affixed to the ground.
While these design features remain true, this is not nearly as important on a solar-powered travel trailer.
Trailers are constantly moving, and the relative position to the sun depends on the exact position of the trailer at any given moment. Thus, solar panels are typically placed flat on the roof to take advantage of the widest range of solar conditions that you may come in contact with while traveling.
If you find solar panels on a wall, I encourage you to silently chuckle inside as the designer clearly cares more about how the solar panels “look” rather than how they function. After all, you can’t see solar panels up on a roof of a solar-powered travel trailer.
Solar panels are only effective when the sun is overhead. Solar panels become significantly less efficient when the sun is low in the sky.
This is called the “angle of incidence.”
The most effective a solar panel will ever be is when the sun is directly above or perpendicular to the solar panel. Even in the sunniest of environments, the early morning and late evening hours will not provide much solar power. For this reason, we typically calculate an average of 5 hours of sun per day. More sun = more power, simple. One area we can control how much power is captured is to increase the exposed area of solar panels. One simple way to accomplish this is to put as many solar panels as possible upon that horizontal roof surface. When the sun is directly overhead, more solar panels = more electricity generated. To put this into perspective, high draw appliances like microwaves, air-conditioners, and hair dryers use about 1,000 watts of power at any given time. If you have a 1,000-watt solar system, you are supplying around enough power to make one of those appliances run. But what if you have a 2,000-watt system? What happens to all that extra power?
That’s where batteries come into play.
If you capture more than you use, the excess is stored in a rechargeable battery system to keep that power to be used at a later time – like, night, for example.
For a truly off-grid solar powered travel trailer, you will need at least 1,000 watts to accomplish the basic tasks required to stay off-grid for short periods of time. If you’re looking to extend that time to weeks, months, even indefinitely, you’re going to need 2 or 3 times more than that.
Based on an energy calculator created by Living Vehicle, about 3,000 watts of power is more than enough to run almost all appliances that are required on a day-to-day basis, indefinitely.
That means you will never need to plug into shore power – as long as the sun is out.
Now that we have all those beautiful solar panels on the roof, capturing power whenever the sun is shining, we need a place to put all that energy. Batteries are a topic in and of itself, and we could talk for days about the size, chemistry, efficiency, etc. For our purposes, I’ll make it simple. I recommend as big of a battery system as you can fit, afford, or otherwise get your hands on. Think of your battery system as you would a gas tank on a motor vehicle. The larger the gas tank, the longer you can go – and the fewer stops you need to make between trips to the gas station.
Except, in the case of a solar-powered trailer, that gas station is directly above you at all times when the sun is out. It’s a beautiful thing.
The reason I recommend a large battery system is because the sun does not always shine. I have traveled days, even weeks at a time when I did not see the sun. Not one watt of power entered my energy system from the solar panels. So, I had to rely on the energy stored when the sun was out. The more energy I had, the longer I could go before recharging. Batteries, or energy packs, are measured in how many watts they may store over a period of time. This is measured in kilowatt-hours. In simple terms, if that 1,000-watt array of solar panels is exposed to the sun for one hour, it will store 1,000-watt-hours, or one kilowatt-hour (kWh) of energy. Use this power as you would! But when it’s gone, it’s gone – you must recharge.
Of course, there are times when the sun just doesn’t come out – winter, for example. I’ve traveled up in the pacific northwest and didn’t see the sun for weeks at a time. There’s only so much energy conservation I was able to do before I simply ran out of power while traveling. This is where backup power generation comes into play.
Having a backup power supply at the ready is nothing new in the recreational vehicle industry. It’s so common that many RV’s, travel trailers, and campers have a primary source of power – a generator.
There are all different types of motor-driven electric power generators, but they all do the same thing – make electricity.
One issue I have with this concept is that manufacturers have relied so heavily on these generators that they have now become the primary source of power when away from shore power. This is a flawed approach, in my opinion.
Generators are an excellent piece of equipment, supplying high amounts of electricity at the push of a button – but there are downsides to generators too. They are noisy, smelly, and often can’t be used where you’re traveling.
Many national parks only allow using generators for one or two hours a day. That’s not a great spot to be in if a generator is your primary source of power.
When you combine a solar-powered travel trailer with a generator, the primary source of power becomes the sun. When the sun is out, power is freely flowing (and yes, that was a pun). There’s nothing better than free, clean, and silent power. Of course, the sun does not always shine, and it’s a beautiful thing to have planned for that moment. Backup power generators at the ready, capable machines ready to supply power at a moment’s notice. Now there are other types of backup power generators besides the common gas- or diesel-powered units, and they take all shapes, sizes, and kinds. One of my favorites is leveraging the engine of the tow vehicle. After all – the trailer does not have an engine itself and requires a tow vehicle to move. The installation of a high-voltage alternator in the tow vehicle may quickly and efficiently recharge an entire trailer energy system in a matter of hours.
It’s a great way to take advantage of what’s already there.
In the end, solar systems are an excellent addition to solar-powered travel trailers. Properly designed, they allow you to harness the seemingly free and unlimited resource of the sun’s power and go farther than ever before possible. When you are hundreds or even thousands of miles away from the nearest gas station, solar power is available. With enough solar panels, a large enough battery pack, and backup power generation when the sun doesn’t shine, that solar travel trailer can go farther than ever before possible. Now that’s freedom.