Before packing up and hitting the road, it’s important to consider how the rarefied air and increased solar radiation of higher elevations can impact your RV’s electrical systems, especially the solar panels. Believe it or not, moving just a few thousand feet higher opens up opportunities to significantly boost your solar generation—if you plan properly.
Harness the Power of Height
It may not seem obvious at first glance, but going higher means more sun. Once you drive up past the lower lying hills and valleys, your solar panels will start bathing in significantly more sunlight. I discovered this altitude advantage first-hand during a weeklong boondocking trip to Colorado’s San Juan National Forest. My 100W roof-mounted solar panel, which reliably delivers 20-30 amp hours per day at sea level, was cranking out nearly double that amount high in the San Juans despite shorter winter daylight hours. That meant we could run our vent fan, lights, and electronics longer without having to fire up the RV generator. After just two days, the battery bank was nearly full by early afternoon. What gives?
Thin Air, More Sun
Here’s the science behind the altitude boost. At higher elevations, the atmosphere is thinner, meaning there’s less air between you and the sun. This allows more solar radiation to reach your panels compared to lower elevations where atmospheric moisture, dust, and pollution filter out sunlight. I like to think of those towering mountain peaks as atmospheric umbrellas, shading the land below while the high passes and ridges bask in sunbeams.
To quantify the difference, for every 1,000 ft gain in elevation, solar radiation intensity increases by about 4% on average. So a 10,000 ft mountain pass receives about 40% more sun than a parking lot near sea level on the same day. My San Juan site at 8,500 ft exceeded the output of my coastal home solar array by 30-50% over the course of a week. Of course, results vary depending on weather and conditions, but the effect is substantial.
The Snowy Bounce
Higher locations also tend to be colder and snowier during winter. You might think all that snow would put a damper on solar output, but it often enhances it thanks to the albedo effect. This phenomenon causes sunlight to reflect more strongly off white snowy surfaces onto your panels compared to bare ground or vegetation. One study measured albedo boosts solar output by 50-80% during winter at high altitude alpine sites in Switzerland.
Similar to the atmosphere, think of fresh blanketing snow as a huge reflector, concentrating even more sun onto your panels. Tilted at the optimum angle, your panels will soak up both the direct and reflected beams, potentially doubling their output compared to being surrounded by dirt or trees. Of course, this benefit only applies when the panels remain clear of snow. But strategically placed and regularly cleaned, they can capitalize on this winter high-altitude bonus.
Coping with Cold
Frigid temperatures are the flip side to those sunbeams. You’ll certainly want to break out the down jackets and mittens when camping above 10,000 ft once the sun dips below the peaks. Subzero nights are not uncommon. Though uncomfortable for us humans, such low temperatures actually benefit solar arrays by reducing panel overheating and electrical resistance.
Most of us know from experience that our phones and laptops don’t charge as quickly on a hot sunny day. Heat causes electrical resistance that dampens current flow. Solar cells exhibit a similar effect. Colder high-altitude temperatures mitigate this by improving conductivity and internal efficiency.
In very cold weather, the gains from reduced resistance outweigh any losses from increased diode junction voltage drops that impede current flow. At night, frigid temperatures radiate excess panel heat into the atmosphere, allowing the cells to operate closer to their optimal temperature after sunrise. My panels in the San Juans on 30°F sunny days outproduced anything I’d seen before.
Optimizing Your Solar Setup
Hopefully you’re now excited about the sizable solar gains waiting at altitude. But to fully capitalize on the high-elevation advantage, you may need to optimize your system and habits. A few tips:
Angle Matters
Pointing your roof panels directly at the midday sun is ideal for maximum energy absorption. As the sun tracks lower across the sky in fall and winter, tilting them upward 15-30 degrees can significantly boost output at high altitude. Regularly adjust the angle to follow the sun’s seasonal progression.
Portable panels offer complete flexibility. Use the adjustable legs to fine tune the tilt anywhere from 0 to 60 degrees to match the sun’s azimuth. I carry two suitcase panels that can be positioned on the ground independently. By tweaking their angles just 15 degrees toward the sun, I measured a noticeable 30% increase in power generation.
Try New Locations
When boondocking in mountain forests, look for open areas to camp rather than under heavy tree cover. Pitch your portable panels in a sunny clearing, or move the RV to maximize roof panel exposure while avoiding shadows from trees.
Sometimes simply turning the rig 90 or 180 degrees makes all the difference between shade and sun beams. Observe how the sunlight filters through trees throughout the day and park accordingly. Apps like Solmetric’s Sun Path Calculator can help identify solar opportunities at your specific location and time.
Keep ‘Em Clear
At home, it’s easy to ignore a dusting of snow on your roof panels. But in the mountains, frequent snow requires diligent attention. Even a thin layer of snow can block over 90% of inbound sunlight. Set up a stepladder to access the roof and sweep off snow before it accumulates. Better yet, invest in a heated mat designed to automatically melt snow so your panels remain uncovered.
Avoid low overnight temperatures that melt snow during the day, then refreeze it at night. Not only will this entomb your panels in ice until noon, it can damage interior components. Park under cover or use insulation when expecting freeze-thaw cycles.
Load Up on Portables
Stationary roof-mounted panels lack flexibility compared to portable systems. Having multiple portable solar generators and foldable panels allows you to spread the array across sunnier spots and continuously adjust positions to match the sun’s movement.
I use an expandable modular system with 200W portable panels that chain together for increased capacity. I can park once then relocate the panels in minutes to sunny clearings. Combining fixed and portable solar provides fail-safe redundancy and higher overall power generation at altitude.
Maximize Your Battery Bank
Nothing beats coming back to a fully charged house battery after an all-day hike. To accommodate the surplus solar electricity at altitude, make sure your battery bank has sufficient capacity. Upgrade to 400-600 amp hours of deep cycle AGM or lithium batteries to take full advantage of your panels.
High altitudes do sap battery performance a bit, but cold temperatures extend charge life, allowing you to utilize more of the theoretical capacity. Prevent overcharging and use a charge controller with temperature compensation to automatically adjust voltage for altitude. Properly maintained batteries can handle high elevation duty cycles.
Location, Location, Location
- Seek out camps above 7,000 ft whenever possible
- Every 1,000 ft gain increases solar intensity by ~4%
- Park the rig to maximize roof panel sun exposure
- Turn the RV to face incoming sunlight
- Avoid shade from trees and terrain
- Pitch portable panels in sunniest spots
- Move panels to follow the sun’s path
- Use apps and tools to identify optimal solar locations
- Account for changing seasons and terrain
Optimizing Your Solar Setup
- Adjust panel tilt 15-30 ̊ to point more directly at the sun
- Increase tilt angle in fall/winter as sun angle decreases
- Add more portable panels for flexibility
- 100-200W suitcase & foldable panels work great
- Keep panels clear of snow accumulation
- Sweep off frequently
- Use heated mats to melt snow
- Load up on batteries – 400-600 amp-hours
- Handles increased generation
- Watch for reduced performance
- Take advantage of cooler temperatures
- Improves panel efficiency & life
Maximize Winter Solar
- Prioritize solar sites with high albedo
- Snow reflection bonus
- 50-80% output boost
- Monitor freeze/thaw cycles
- Avoid overnight icing of panels
- Park under cover or insulate panels
- Prevent internal condensation
- Let cold nights maximize cooling
- Improves next day performance
Note: Above tips generally apply above 7,000 ft and vary based on conditions and system specifics.
Thin Air, More Sunlight
As you climb up the mountain roads and passes above 7,000 feet, you rise above much of the atmospheric moisture, pollution, and dust that filter out sunlight down below. With fewer air molecules between the sun and your panels, more intense direct and diffuse radiation reaches the solar cells. This thinning effect increases by about 4% for every 1,000 feet gained.
So if your panels typically see 1,000 watts per square meter down in the valley, up at 8,000 feet they could get 1,160 watts without changing anything! Park at tree line around 10,000 feet and you may hit 1,300 watts. These numbers add up, especially multiplied across your entire solar array.
Snowy Reflection Boost
Ever notice how bright sunlight glares off fresh powder? Solar panels do too! All that reflected light beams additional energy onto your panels. This albedo effect can increase winter solar output by 50-80% in the mountains compared to little or no snow gains down below. But to benefit, keep the panels clear of snow buildup and icing by parking strategically and sweeping frequently.
Coping with Cold Nights
Frigid overnight temperatures may have you bundling up, but they bring their own solar advantages. The cold helps panels operate more efficiently by reducing internal resistance and preventing overheating. This improves conductivity and extends battery life. Just be sure to protect batteries from freezing and use charge controllers that compensate for reduced voltage in extreme cold.
Optimizing Your Setup
To really maximize your mountain solar potential:
- Tilt panels at steeper angles to point directly at the low winter sun – 15 to 30+ degrees
- Utilize portable panels that can be moved with the sun’s path
- Park to take advantage of reflective terrain like snow and avoid shade
- Load up on batteries – 400+ amp-hours let’s you use the extra generation
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