You won't get a return on your solar investment if you prefer full-hookup RV parks and campgrounds. However, if you'd rather go boondocking in the sunny Southwest for extended periods, then an RV solar system designed for your needs may provide the energy independence you're looking for. Still need answers? Here are answers to common questions and misconceptions new RV owners have about solar.
Having electrical independence is awesome! Solar has greatly enhanced our RVing experience and expanded our camping options.
My wife and I enjoy the freedom of traveling and camping without hookups and have been powering our RV from solar for many years.
We don't use power-hungry appliances for extended periods and don't have a residential refrigerator. Our mid-sized off-grid solar system and battery bank provides enough energy to power our RV indefinitely as long as there's sun. Our large AGM battery bank has enough reserve capacity to power our RV for at least a couple days without being recharged. In fact, we rarely plug in anymore.
We also know that solar is certainly not for everyone who owns an RV.
Since you're reading this, I'll assume you're thinking of adding solar to your RV and still have unanswered questions. So keep reading, this article is for you.
How Can You Benefit From Solar?
The only time you will benefit from solar is when your RV is disconnected from shore power. There is no reason to have solar on your RV if you primarily stay in full-hookup RV parks. If you prefer to camp in areas where there are no power hookups, then solar may be worth considering. If occaisional boondocking is your thing, then a portable solar panel kit may be all you need to benefit from solar and avoid a potentially costly permanent installation.
When not on shore power or generator, your batteries become your primary source for DC power. Onboard or portable generators do a good job powering your RV but require a steady supply of gasoline to run. The noise levels can also disturb nearby campers. A solar charging system requires no gas, makes no sound and can charge your batteries for hours and hours unattended as long as the sun is shining. In fact the sole purpose of solar panels on an RV is for battery charging.
A common misconception is that solar panels will power your RV. While this is not entirely false, it is a mistake to think of solar panels in that capacity. As I've stated the primary purpose for solar panels on an RV is to recharge your battery bank when your RV is not connected to shore power or powered by generator.
Why don't RVs Come With Solar?
Solar charging systems are not standard equipment on most RVs as they only benefit RVers who camp for days at a time in areas where there are no power hookups. So solar remains a custom option like having a satellite dish installed. Many RV manufacturers will pre-wire for solar panels to simplify the process of running cable from the roof into the RV.
In a well designed RV solar charging system however, there are many factors unique to each installation that determine cable type, thickness and length. For this reason most "wired for solar" dealer configurations fall short.
How much does an RV Solar System Cost?
The cost of a permanently installed off-grid solar system can run from $1,500 for a very basic system up to $15,000 or more for a high-end system to run a residential refrigerator or air conditioner. Here's why the "real cost" can get this high.
Many new RV owners love the idea of free camping without hookups and using solar panels to power their RV. What they really want is a battery powered off-grid electrical system that powers their RV day and night while camping in those amazing locations.
Let's face it, solar energy is pretty cool. Which is why many new RV owners jump directly into pricing solar panels online trying to figure out "How many solar panels do I need to power my RV?"
In reality, there are several components needed to take your RV off-the-grid with solar. Solar panels are just one piece of the puzzle. You should really start with your battery bank.
Components of an off-grid solar powered electrical system
- Deep Cycle Battery Bank (adequately sized for your needs)
- High Quality Power Inverter to convert battery power to household AC power
- Battery Monitoring System to keep track of how much power you have available
- Solar Panels (usually 2 - 8 panels or as many as you can fit on your roof)
- MPPT Solar Charge Controller to manage the charging of your batteries from solar
- Connection Equipment (Cables, Connectors, Fuses, Cut-Off Switches, Circuit Breakers and Junction boxes)
- Auxiliary Generator (optional)
- Battery Charger (used with generator - optional)
You can see how the full system cost can add up quickly.
Also keep in mind that the price and features available for each component vary considerably. You can easily spend $1,000 to $10,000 on deep cycle batteries alone. A hybrid power inverter like this one that automatically switches between power sources typically costs around $1,500 compared to a $400 basic pure-sine inverter like these. The list goes on.
Then add the expense to design a custom system and install it on your RV. You can cut labor costs if you're a qualified do-it-yourselfer.
Your individual power needs will ultimately determine the size, cost and components you'll need. There's no one-size-fits-all solution.
Here are some ball-park estimates for three common off-grid configurations (not including labor):
Basic Off-Grid Solar System
This setup can power basic small electronics like lights, laptops, mobile hotspot, TVs, and cell phone booster.
- 220 Ah of flooded deep cycle batteries
- 200-300 watts of solar panels
- 1,500 watt pure-sine inverter
- 20 Amp MPPT Charge Controller
Cost of components: $1,500 to $3,000
Typical Boondocking Off-Grid Solar System
This setup can power small electronics plus periodic use of a microwave oven, coffee maker, hair dryer, electric blanket.
- 450 Ah of flooded deep cycle batteries
- 400-600 watts of solar panels
- 2,000 or 3,000 watt pure-sine inverter
- 30-50 Amp MPPT Charge Controller
Cost of components: $4,000 to $6,000
Large Power Load Off-Grid Solar System
This type of setup can power a residential refrigerator 24/7 plus other essential equipment.
- 600-800 Ah of lithium batteries
- 800 to 1000 watts of solar panels
- 3,000-4,000 watt hybrid inverter
- 60 Amp MPPT Charge Controller
Cost of components: $12,000 to $18,000
Is solar worth the investment?
If you are a new RV owner I recommend using your RV for a while before making any major upgrades. Over time you will figure out what your camping preferences and limitations are. You'll be in a better position to decide whether an investment in solar is something you'll benefit from. Seasoned RV owners, on the other hand, will probably know whether solar is a necessary feature when purchasing a new RV.
If you feel camping off-the-grid is something you're interested in, then I encourage you to try it out first before making a significant investment in solar or generators. Consider starting out with a portable solar panel kit. There is no permanent installation required and they provide plenty of power to keep your batteries charged. Just store the portable panel when you don't need it.
You could even create your own portable solar battery charger. Building your own is a fun way to learn the basics of solar. Here's a simple project video showing how to build a basic portable solar charger.
How Can Off-Grid Solar Expand Your Camping Options?
When we first started RVing, we primarly stayed in RV parks. We didn't even consider locations that did not have full-hookup sites. Over the years our preferences have changed. We still stay at RV parks periodically, but prefer to seek out more scenic locations.
At first my wife was a bit uncomfortable with the idea of being off-the-grid and having to sacrifice too many creature comforts. These days we don't have to sacrifice much while off-the-grid and she is totally on-board with boondocking without hookups.
There are many beautiful campgrounds located on public, National Park, or State owned land. Camping at these campgrounds is inexpensive and often free. However, what you gain in beautiful scenery and solitude you lose in amenities.
Having a totally self-contained and self-sufficient RV prevents us from having to sacrifice much. In fact we can function quite well off-the-grid without campsite amenities. We have more options for camping, are more spontaneous, and even save money by not relying on expensive RV parks.
Do you need a generator if you have solar?
Don't ditch your generator for solar. You'll need to put back the power you took out of your batteries, even on those days when exposure to the sun is limited. This is when a auxilliary generator comes in handy. A generator can also power an air conditioner, heater or other power hungry appliance when you're battery bank and inverter can't.
If you don't have a large on-board generator, a small portable generator can provide enough power to recharge your batteries and run a few small appliances.
There are cases when some have abandoned their generator completely and made the necessary adjustments for living solely off of solar. As for us, we have less of a need for a generator since installing solar and a large battery bank. Solar is our primary source of battery charging, but we still like the security of having a generator available if we need it. We also boondock only in locations with a moderate climate. Extremely hot and humid climates are generally not optimal for boondocking with solar.
What can you power with solar?
The solar panels on your RV are used mainly for battery charging. Therefore, the amount of power (electrical load) you can draw is determined primarily by the capacity of your battery bank and inverter, and NOT by the amount of solar on your roof. This is a common misconception people have when they ask "how many solar panels to I need to run my whatever?" Instead they should ask "how much battery capacity and what size inverter do I need to run my whatever?"
Lights (preferably LED), laptop computers, radios, fans, TVs, water pump and other small items can be used while on battery/inverter power. In some cases small coffee makers, low power microwave ovens, toasters, and low power hair dryers can be used for very short periods depending on your battery's state of charge and size of your inverter.
|I put my inverter to the test to see if I could make coffee and microwave popcorn. Watch the video and see what happened.|
High power consumers like air conditioners, heat pumps, space heaters, or water heaters generally require more power than a standard RV solar/battery/inverter system can provide.
Power hungry components like those will rapidly drain your RV batteries. For this reason, most RVers who rely on solar relocate throughout the year to sunny locations that have moderate climates. Keeping cool means opening windows and/or turning on an electric fan, not running an air conditioner.
Is it possible to run an air conditioner off of an RV battery bank? Yes it is. Is it a practical solution? No, not at this time. As the price of off-grid lithium battery systems continue to fall, we may start seeing lower powered AC units for off-grid RVs. For now, I'd stick with a good fan.
Residential refrigerators are also large power consumers since they run 24/7. If your RV has a residential refrigerator that only runs on electricity, you'll need a large lithium battery bank and solar array.
Experiment and determine how much power you need?
The best way to figure out what your needs are is to just go do some dry camping for a few days while measuring your power usage. To get an accurate indication of your state of charge, you will need a battery monitoring system. Without one, you'll simply be guessing and probably guessing wrong. The battery voltage or level gauge your RV came with will not give you an accurate measure of your battery state-of-charge (how much reserve power available). So this is an essential first step to figuring out how much power you need while out camping.
Take your RV dry camping and watch that battery monitor. You won't need solar panels for this experiment. Just use your RV and see how long it takes to get down to 50 percent of available capacity (if using lead acid batteries). Can you make it through a 24 hour period? When you reach 50 percent, well that's all you've got. It's time to recharge your battery bank.
Take note of what equipment you've used and for how long. If you need more power, add more battery capacity and try again. Try to get through a good 24 to 48 hours before you need to recharge. Everybody's needs are different, but having enough battery capacity for one or two days is a good benchmark to start with.
Keep that 50 percent of battery capacity in mind if you are using lead acid batteries (i.e. flooded or AGM batteries). 50% is your "usable" capacity. For example, if your 200 amp hour battery bank gets down to 50 percent in 24 hours, then you've used approximately 100 Amp Hours of capacity during that time. So if you need 200 amp hours to live, then you'll need a 400 amp hour battery bank. Once you figure out how big your battery bank needs to be, you will have a good idea of how much solar you will need to keep those batteries charged up.
If your RV has lithium batteries, then you usable capacity will be 80 to 100 percent of the batteries rated amp hours.
A simple way to estimate how much solar power you'll need is to apply the 1 Watt to per Amp Hour rule. Simply put, your maximum solar output (in watts) should equal your battery capacity (in amp hours).
For example: A 400 Amp Hour battery bank will need roughly 400 Watts of solar. This is just a rough measure to get you in the ball park. You should also take into account the efficiency of your panels, amount of sun in your area, cable size/length, and power loss between your solar panels and batteries (i.e Voltage Drop). I recommend adding at least 20 percent to the solar estimate to account for these factors.
That should get you off to a good start. When you are ready for more, these articles will help you take it to the next level.