RV Solar Power Basics: 5 Things You Need to Know

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Introduction

As more RVers opt for boondocking in off-grid locations, many are turning to solar energy to power their adventures. Solar panels allow RVers to create power without the need for external sources, offering wider possibilities, increased independence, and potentially cost savings. However, before taking the leap and installing solar on your RV, it’s important to understand the basics to ensure your RV solar kit is set up for long-term success. In this guide, we’ll walk you through five things to consider before you add solar to your RV so you can make an informed decision and enjoy the full benefits of your off-grid adventures.

Thinking about camping off grid? Be sure to also read our article, “Best Boondocking Resources: Everything You Need to Know About Dry Camping in an RV.”

1. How Much Solar Power You Need for Your RV

So you’re thinking about adding solar to your RV. Where should you begin? The first step is understanding your RV’s daily power needs. Calculating your energy usage in watt-hours will tell you how much power your solar panels need to generate.

Calculating RV Solar Needs

1. Find the power ratings of all the appliances in your RV. 
2. Estimate how many hours you typically run each appliance. 
3. Multiply wattage by hours of use. For example, a 10-watt LED light used for 8 hours equals 80 watt-hours per day.

Repeat this for all your appliances to estimate your total daily energy usage. You can also use a load calculator, such as an online energy usage tool, or use a plug-in power monitor to measure your usage directly. 

Matching Solar Panels to Energy Needs

Let’s say you calculate your total energy usage to be 1600 watt-hours per day. You’ll then need to determine how many solar panels you’ll need to give you these 1600 watt hours. 

Solar panels are rated by their wattage, but the actual energy they produce depends on sunlight. For example, a 100-watt panel might generate its full rating only under ideal conditions—like high noon on the equator. In most locations, you’ll get a fraction of the panel’s rated capacity. You can use a solar power efficiency tool like this one to help you determine how much energy you can expect to get from your solar panels based on location and time of year.

Let’s say you calculate that each 100 watt panel will offer around 375 watt-hours per day. You can now use these numbers to find out how many solar panels you’ll need to meet your energy needs.

If you divide 1600 (your total energy expenditure per day) by 375 (watt-hours offered per solar panel), you’ll find that your solar panels would need to be rated at least 427 watts to provide all the energy you need in a day. To ensure reliability during overcast weather or shorter winter days, it’s wise to build in extra capacity. You might choose to install solar panels that offer 500 watts in total to ensure enough margin.

By calculating your daily power consumption, you can select the right solar panel system for your RV, ensuring you’re fully prepared without overspending.

What Does This Mean in Plain English?

Let’s break this down into real-world examples that every RVer can understand.

A typical 1000-watt microwave running for 15 minutes uses about 250 watt-hours. A small RV air conditioner (11,000 BTU) draws around 1000 watt-hours for each hour of operation. A Splendide washer/dryer combo uses approximately 300-400 watt-hours per load on average. A 32-inch LED TV typically uses about 30-50 watts, meaning 4 hours of evening entertainment would consume around 120-200 watt-hours.

To put this in perspective: if you want to run your air conditioner for 4 hours, use your microwave for 30 minutes total, do one load of laundry, and watch TV for 4 hours, you’re looking at about 4,750 watt-hours of energy for just these activities. Using our earlier calculation method, this would require around 1,300 watts of solar panels (typically 13 panels at 100 watts each) under ideal conditions. And remember, that’s not counting your other daily power needs like lights, water pump, fans, and device charging.

This is why many full-time boondockers who want to run their air conditioning opt for solar panel systems in the 1,500-2,000 watt range, often combined with a robust battery bank to store all that energy for cloudy days and nighttime use.

Solar Power for RV Air Conditioners: How much solar to run RV AC?

Many RVers specifically want to know about solar power for RV air conditioners, since they’re typically the most power-hungry appliance in any rig. Running an RV air conditioner on solar power requires a substantial setup – you’ll need at least 1,000-1,500 watts of solar panels just for the AC unit alone.

But it’s not just about the panels. To run an air conditioner effectively on solar, you’ll also need a robust battery bank (generally at least 400 amp hours of lithium batteries) and a pure sine wave inverter rated for at least 3,000 watts to handle the AC’s startup surge. While this level of solar setup represents a significant investment, many full-time RVers find it worthwhile for the ability to stay cool while boondocking in warm climates.

2. Types of RV Solar Power Setups for RV owners

There are two major types of solar panels that you can invest in for your RV: roof-mounted and portable. 

Roof-Mounted Solar Panels

Roof-mounted solar panels are permanently installed on the roof of your RV. These panels stay in place at all times, providing continuous power without the need for setup or take-down.

Pros:

Roof-mounted panels are always available for use with no need for daily setup. They have the capacity to offer more power due to the ability to install more panels. (Note: Be sure to consider your battery’s capacity as well as the number of solar panels when trying to increase the capacity of your electrical system. More on that in the next section.) Finally, with roof-mounted panels, there is no need to store panels inside the RV. These may be best for full-time RVers and frequent boondockers.

Cons:

Buying and installing roof-mounted panels are more expensive than portable panels. Their efficiency may decrease in shaded areas or if parked away from optimal sunlight. Also, once installed, you can’t move the panels to adjust to changing conditions.

Portable Solar Panels

Portable solar panels are free-standing units that can be placed on the ground or set up wherever sunlight is best. These panels offer more flexibility than roof-mounted solar panels.

Pros:

Portable solar panels can be placed in the best sunlight depending on the conditions. They are less expensive than roof-mounted systems, which can make solar energy a practical option for those on a budget. Portable solar panels may be best for part-time RVers or those who only need occasional off-grid RV power.

Cons:

Portable solar panels must be moved each day for optimal sun exposure. They need to be stored while on the road, which means they will take up room in the RV when not in use. They could be stolen if left unattended outside, and their limited size makes it difficult to generate enough power for energy-intensive appliances compared to roof-mounted systems.

That said, portable solar panels require minimal setup and can come in handy for temporarily powering small appliances or charging a cell phone.

Here’s an example of portable RV solar phttps://amzn.to/4adReHfanels available on Amazon.

Portable Solar Generators

A portable solar generator combines a battery, inverter, and charge controller into a single movable unit – offering RV owners a simpler plug-and-play alternative to traditional solar setups that require purchasing and installing separate components.

Pros:

Since everything is integrated into one system, you won’t need to worry about matching components or complex installation – just connect your solar panels and start generating power. The ability to easily move these units between locations adds versatility, while built-in features like battery monitoring and multiple charging options (including shore power and vehicle charging) provide peace of mind when traveling.

Cons:

Portable solar generators typically carry a higher upfront cost compared to purchasing individual components, and their all-in-one nature means you’ll have less flexibility to customize or expand your system to meet specific needs. While adequate for most RV applications, they may also offer less overall power capacity than a custom-designed solar setup with multiple batteries and panels.

What’s the Best RV Solar Panel Setup?

Ultimately, your decision depends on your energy needs, budget, and camping style. Roof-mounted panels suit full-timers seeking a permanent, high-capacity solution, while portable panels offer flexibility for part-timers or those with lower energy demands. Portable solar generators provide a middle ground, offering simplified setup and versatility at a higher upfront cost than individual components. Consider your travel habits, technical comfort level, and power usage to find the best fit for your RV lifestyle.

3. Battery Storage and Capacity

It’s crucial to understand how your solar panels interact with your battery as part of your RV’s electrical system. 

Here’s what you need to know. 

Your RV’s battery powers all electrical functions, whether AC (alternating current) or DC (direct current). It can be charged in three ways: plugging into a campground pedestal, using a generator, or harnessing solar energy.

Think of your battery like a bucket—it can only hold so much energy before it’s full. Once fully charged, any additional solar power is wasted and can even harm the battery.  Therefore, it is essential to ensure not only that your solar panels can generate enough power to meet your needs, but that you have a battery bank that can store the right amount of power. This includes being able to store enough energy to use overnight, when your solar panels are not generating any power.

Common types of batteries

There are a few common types of batteries that you can use to power your RV.

Lead-acid: While affordable, they are heavier, require regular maintenance (checking water levels), and have a shorter lifespan compared to lithium-ion. Their capacity decreases over time.

Lithium-ion: These batteries are increasingly popular due to their high efficiency and lifespan. They are significantly more expensive upfront than a lead-acid battery, but they are lightweight, long-lasting, and require little maintenance.

Sizing your battery

You’ll need to determine what size battery bank your RV needs to ensure you can store enough power to use when your solar panels cannot harness energy (like at night or in overcast conditions). You can use this simple formula to determine how large your battery bank should be: 

​​Using our earlier example of 1600 watt-hours per day, divide this by the battery’s voltage (e.g., 12V). This gives you 133.33 Amp-Hours, the capacity needed to meet your energy needs. Remember that for lead-acid batteries, you’ll want to double this number to ensure the charge doesn’t fall below 50%, which can cause damage. Check your RV’s current battery to see its amp-hours (Ah) are enough to meet your needs if you switch to solar or if you’ll need to invest in a more robust battery bank.

For a more in-depth discussion about RV batteries and solar power, check out this YouTube video by DIY Outdoor Life.

4. Cost Considerations and Budgeting

When outfitting your RV with solar power, it’s important to understand the costs involved. Here’s a breakdown:

Solar Panels

Panels typically cost $100 to $350 each, with a 500-watt system needing around 5-6 panels, totaling $500 to $2,100.

Charge Controller

Charge controllers regulate power from panels to batteries. A PWM controller like this one can cost less than $100, while an MPPT controller like this one can range from $150 to $500.

Batteries

Battery costs depend on type. Lead-acid batteries tend to fall below $300, while lithium-ion batteries are more expensive, ranging from $500 to $2,000 or more.

Inverter

An inverter converts DC power to AC. In other words, an inverter allows you to send power from your battery to the electrical outlets in your RV for things like charging a phone or plugging in a TV. An inverter may cost between $100 and $250, with higher-quality models up to $500.

Additional Costs

Other costs associated with RV solar panel installation include mounting hardware ($50 to $300) and wiring/connectors ($50 to $200). Adding panels or upgrading to a higher-capacity RV solar battery later as your energy needs increase can also increase costs.

DIY vs. Professional Installation

Choosing to install your solar panels yourself will save you money on labor. If you choose to go with a professional to install your system, you may add $500 to $2,000 for the cost of installation. Whether to take a DIY or professional installation approach will depend on a number of factors like your personal experience, budget, and the type of solar panels you choose for your RV.

Cost of Portable Solar Generators

All-in-one portable solar generators typically range from $2,000 to $5,000 for the base unit. While this may seem higher than purchasing individual components, the price includes an integrated battery, inverter, and charge controller. Additional expansion batteries or solar panels would increase the total cost, but you’ll save on mounting hardware and installation since these units are designed for plug-and-play operation.

5. Maintenance and Troubleshooting Solar for RVs

Proper maintenance is essential to keep your RV solar system running efficiently for years to come. Here are some tips on how to care for your setup and troubleshoot common issues.

Clean Your Solar Panels

Dust, dirt, and debris can reduce panel efficiency. Clean your panels regularly with water and a soft cloth to keep them working at their best. Avoid harsh chemicals that could damage the surface.

Inspect Connections and Hardware

Check all wiring, connectors, and mounts for wear and tear. Tighten any loose connections and replace corroded parts to avoid power loss or damage.

Monitor Battery Health and Charge Controller Settings

Batteries lose efficiency over time, so regularly check their voltage and overall health. Ensure your charge controller is properly set up to optimize charging based on the battery type.

Power Loss

If you’re experiencing power loss, the issue may be due to shading or dirt on your solar panels. Ensure that panels are free from obstructions, and clean them if needed. Also, check if nearby trees or structures are casting shadows during peak sunlight hours.

Battery Underperformance

If your battery isn’t holding charge, it may be nearing the end of its life. Check the battery’s age and capacity. Lead-acid batteries, in particular, degrade faster, so be prepared to replace them when necessary.

Inverter or Charge Controller Errors

Inverter or charge controller issues are often due to settings or manufacturer errors. Always consult the user manual for troubleshooting steps and reset or adjust settings if needed.

Proactive Care

Regular maintenance and early detection of issues can help extend the lifespan of your RV’s solar system. Taking the time for routine checks will save you money on repairs and prevent unexpected power outages. It can be helpful to keep a basic solar toolkit with essentials like multimeters, fuses, and spare connectors for quick fixes while on the road.

Conclusion

Adding solar power to your RV setup offers many benefits, from greater independence to the freedom of camping off-grid. With solar power, you can enjoy peace of mind knowing that you’re self-sufficient, no longer bound by the need for campground electrical hookups.

However, setting up an RV solar system requires thoughtful planning to ensure a smooth and worthwhile transition. Whether you choose a traditional panel installation, portable panels, or an all-in-one solar generator, understanding your power needs and battery capacity, factoring in costs, and staying on top of maintenance are key to getting the most out of your system.

As you research or plan your RV solar solution, keeping these essentials in mind will ensure that you make well-informed decisions that fit both your technical comfort level and your camping lifestyle.

Ready to learn more about off-grid camping? Check out our comprehensive guide “Best Boondocking Resources: Everything You Need to Know About Dry Camping in an RV” for everything you need to know about making the most of your adventures off the grid.