There is a growing interest among Baby-boomers and even Millennials to live full-time on the road in an RV. Some of them want to experience off-grid camping in national parks using solar power. Although it is possible to harvest the Sun’s energy to produce clean power, it comes at some expense and you must be willing to compromise.
Installing several solar panels on the roof of an RV may seem like the natural choice, but you may very well be creating unforeseen problems with water migrating through cracks and gaps in the caulking caused by Sun damage or road motion. The increased surface area can also impact mileage and even create metal fatigue on an already thin membrane.
Watt You Need
Many folks underestimate their power needs when it comes to solar and do not take into consideration the number of sunny days available, look angle, bad weather or panel positioning. Just adding more solar panels has little effect if you don’t increase your storage capacity. Lead-acid batteries are very heavy and this adds to your vehicles towing capacity. To make matters worst, a lead-acid battery should not be discharged below 50% of capacity, at least on a regular basis. This means that a 400 AH (ampere hour) lead-acid battery bank can only be expected to produce 200 AH.
Do Your Homework
This ebook is not an attempt to discourage you from exploring the wonderful world of solar, in fact, I encourage you to research and explore your options. Solar is a wonderful thing. I have been making portable and permanent solar trackers for my own use for the last 10 years. I have personally solarized my Barn and on a couple of outbuildings. I also built a passive solar furnace to supplement the heating system in the Barn.
My solar installations worked because I did my best to match the power produced by my solar panels with the storage capacity of my batteries. I produced 500 Watts and stored 1000 AH (based on 50% discharge). This equated to (10) 100 AH batteries or nearly 1000 pounds.
The alternative to lead-acid is LiFePO4 batteries. They are one third the weight, can be charged 3 times faster and can be discharged down to 70-80%. They are also 3 times more expensive.
Fixed Angle Solar Panels
This is a topic that has been hotly contested for years by solar enthusiasts. Most would argue that there is not enough power gain to justify the cost. That is actually true if you are basing it on a tracking cost of 1K-3K dollars. However, a solar panel mounted on a flat surface is not as efficient as a panel that tracks…period. You can expect to see between 25-35% more power with a dual axis tracking system. Just because it has not been cost effective in the past does not mean it can’t be done now.
Fixed solar panels are greatly impacted by shade cast by trees and other obstructions. A partially shaded panel will reduce the overall output of the system, so consider this when laying out your system.
Build Your Own Solar Tracker
There are actually very few portable solar tracking systems on the market. They are either very heavy, not portable and they are expensive. The least expensive model is $1200.
I have created a system that can be built by anyone using readily available parts. It is lightweight, easily assembled and it can be built for around $300.
The plans include, drawings, dimensions, parts list (Amazon Affiliate Links), photographs and a video of it in operation. It consists of a sturdy ground mounted tripod and a universal mount that expands to accommodate panels from 50-watts to 100-watts. It utilizes the new flexible mono crystalline solar panels that are so compact they can be stowed under a mattress. I have listed everything you need to charge your RV storage battery through the Zamp receptacle or directly at the battery.
Imagine building your own complete portable solar tracker:
$350 for a 50-watt system
$450 for a 100-watt system.
This design can be modified to be mast-mounted on the side of an RV. It can also be made permanent by cementing a pipe in the ground and swapping out flexible solar panels with rigid solar panels.
Just as people moving into tiny homes need to down size you too must consider what it is you really need to power with solar. If I was to set out to boondock for a few days at a time I would bring a small portable propane fired generator, and only if I could safely transport and protect it. I would bring a small gasoline fired generator if I could safely stow the gas.
I would have a 100 watt tripod mounted tracker on the ground and another one mounted on a mast on the side of the ladder. I would bring a large portable and foldable 200 watt solar panel just to help out on overcast days.
I would avoid running an air conditioner but I would run DC powered fans to cool the space.
I would focus on providing power to essential DC loads and carry a portable 2000 Watt pure sine-wave inverter for limited AC usage.
I would install (2) 100 watt LiFePO4 batteries and I would not expect to stay off grid for more than 2 days.