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ZDNET’s key takeaways
- Positioning panels is key to the best output, as is keeping them clean.
- Test and care for your gear to ensure reliable solar power.
- Off-grid solar teaches balance: collect wisely, and consume carefully.
Fixed solar panels on buildings are, well, fixed. They are installed and, more often than not, receive little to no attention until something goes wrong. Portable panels — or temporary panels, as I tend to think of them — are an entirely different matter. They thrust you into a space that blends science with ingenuity. The sun becomes both a teacher and a lifeline, and every watt harvested stands as a testament to resilience, creativity, and the timeless romance of self-sufficiency.
I’m not battling Mother Nature. I’m negotiating, or sometimes even begging: “Please give me some power so I can charge my phone to send that message back home… and do a bit of doomscrolling.”
Well, that’s how I see it, anyway.
Also: I used a single power station to keep my off-grid cabin running – how it all worked out
What I’m going to cover here primarily relates to portable panels that connect to portable power stations (sometimes referred to as solar generators), but I’ll also share a few tips and tricks for those with fixed installations on roofs and RVs to help them get the best from their investment.
Which solar panels should you buy?
If you’ve already bought some panels and don’t want to feel like you might have made a mistake, skip this section. Otherwise, read on, because this is where I see people make some big — and expensive — mistakes.
Select a solar panel that matches your energy requirements. For example, low-wattage panels (50W to 100W) are ideal for camping or charging small devices, while higher-wattage panels (200W to 400W) are better suited for RVs or powering larger systems.
It’s also wise to choose panels that provide slightly more energy than you think you’ll need. People almost always underestimate their energy requirements, and having extra capacity accounts for things like sporadic sunlight or unexpected power needs.
Also: After two years of testing, wind power still can’t replace solar for me – here’s why
High-efficiency panels (with efficiencies around 23%) generate more energy even in suboptimal conditions, such as cloudy weather, partial shading, or poor positioning. This ensures you get the most power possible from your setup.
Another consideration is weatherproofing. You can now find panels with high IP ratings (IP67+), which means they’re resistant to water and dust, perfect for outdoor adventures.
You can also get rigid, 25% efficiency panels that are great for RVs, homes, and cabins. These can output both 12V and 24V, and if you connect one of these to a 12V Li-ion battery and an inverter, you have quite the setup.
And, just to add more complexity to the equation, some power stations allow you to connect two or more panels, scaling up your power-generating capability. This can be a game-changer if you need more energy on the go.
How to position your solar panels
OK, this is where science meets ingenuity.
I’m going to explain how to position your panels to coax the greatest amount of precious energy from even the most sullen skies. But once you’re out in the big wide world, you’ll need to get creative to position the panels. If you want the TL DR version, here it is:
Position your panels so they face south (assuming you’re in the Northern Hemisphere) and angle them at about 45 degrees.
With 9 a m April sun in the UK, this 200W panel was pulling in 170W.
Adrian Kingsley-Hughes/ZDNET
If I’m in a hurry or not desperate for every watt of power, this is what I do. It’s a good compromise between effort and return. But if you want to master solar power collection, here are some of my top tips:
1. Align with solar noon
Use a sun-tracking app (iOS and Android) or go old-school with a compass to align panels perpendicular to the sun at solar noon for maximum output. Some apps (Lumos is one I use a lot) let you overlay the path of the sun onto Street View imagery, so you can see where the sun will be without leaving your home.
Lumos is a great app for seeing where the sun at a specific time will be overlaid onto Google Street View imagery.
Adrian Kingsley-Hughes/ZDNET
2. Tilt the panel based on latitude/season
Set the tilt angle to your latitude (apps can help with this — iOS and Android) and adjust by ±10 to 15 degrees for summer or winter. Don’t worry, you can eyeball this — it doesn’t have to be pinpoint accurate. But don’t be tempted to leave them flat on the floor because this is a bad position for them unless you’re at the equator.
Only do this if you’re at the equator.
Adrian Kingsley-Hughes/ZDNET
3. Open the panels completely
Don’t be lazy. Unfold them completely.
Open your panels out fully to maximize their solar collecting power.
Adrian Kingsley-Hughes/ZDNET
4. Dynamic adjustment
Move panels every couple of hours to follow the sun’s path across the sky. This one trick can boost your solar collection efforts by up to 30%. A quick way to check alignment is to ensure the panel’s shadow falls directly behind it. You can also get a simple and cheap shadow compass tool you can use for this. Some solar panels come with a built-in shadow compass to make aligning easier.
Some panels have a shadow compass built into the panel, making alignment easy.
Adrian Kingsley-Hughes/ZDNET
5. Adapt, improvise, overcome
Many panels come with shadow compasses or built-in features to help with alignment. Alternatively, you can improvise with trekking poles, sticks, or rocks for precise positioning.
6. Keep your panels clean
Even a light coating of dust can significantly reduce efficiency, so regularly wipe them down with a soft cloth. If they get really bad, you can get a wash for them. Avoid using rough cloths or harsh chemicals, as scratches on your panels are worse than dust and can’t be removed.
Keep your panels clean of dirt and dust.
Adrian Kingsley-Hughes/ZDNET
7. Avoid trees
Not only do trees cast effective shadows, but they also shed leaves and are home to birds that might leave poop on your panels. I try to keep away from trees whenever possible.
Once everything is set up, keep an eye on the power input for your portable power station. This will tell you if everything is working properly or alert you if a cable has become disconnected or a panel has fallen flat on its face.
The worst panel orientation.
Adrian Kingsley-Hughes/ZDNET
Solar panel tricks for bad weather
While the above tips work well in good conditions, you can still get a decent amount of power from a solar panel in cloudy or overcast weather.
Also: I stopped guessing which AA batteries are dead – this charging station keeps them in check for me
Here’s how:
Diagram of three solar panels connected in parallel to a portable power station.
Bluetti
- Steepen the angle of the panels
In diffuse light conditions, tilt panels to a steeper angle to maximize the collection of scattered light. This also helps any rain roll off the panels.
2. Make use of reflective surfaces
Snow, sand, or light-colored rocks can be used to reflect light toward your solar panels, increasing their energy collection area. I’ve also used emergency blankets or white tarps to boost light collection in winter.
3. Use multiple panels
This is where having more than one panel really helps. If possible, connect them in parallel (multiple panels feeding into one cable that connects to the power station) rather than daisy-chaining them in series.
4. Leave weatherproof panels outdoors
If your panels are weatherproof, leave them out to do their thing. Just make sure to secure them so they don’t blow away, and tidy up the cabling to prevent it from flapping in the wind and disconnecting.
Don’t forget to test your gear
Don’t be the person who buys a bunch of gear and immediately heads off on a multi-day adventure without testing it first.
Also: Need power at the campsite? This portable battery station has several days worth
Take your solar panels and portable power station out at home — or to a nearby park — and experiment with setting everything up. This experience will be invaluable when you’re out in the field. You’ll become familiar with what connects where, how to position your panels, and how to move them around for maximum efficiency. Plus, you’ll figure out if you’re missing a cable or other essential component before it’s too late.
Also, take care of your gear
Portable panels can take quite a beating, but that doesn’t mean they’re indestructible. Don’t stand on them or pile things on top of them, don’t flex them too much, or fold any joints the wrong way, and don’t pull or drag them by the cables.
Also: Bluetti AC240 review: One of the most durable power stations I’ve tested
Also, when you’re done with them, clean them and put them away properly. This way, you should get years of service from your panels.
Upgrade your mindset
Off-grid solar means changing your mindset a bit, and moving beyond the idea of AC outlets that can provide endless power, and thinking of power as the precious resource that it actually is. When you’re off-grid or in a blackout situation, every watt matters, and this shift in perspective encourages you to think not just about how much power you can collect, but also how you consume that power. It’s a balancing act between production and conservation, and mastering this balance is key to thriving off-grid.
Also: Are portable solar panels legit? I saved $30 a month with these (and they’re $400 off)
This mindset shift can not only be empowering, but it can also help you save money on your power bills when you’re back on-grid. Over the past few years, I’ve become very conscious of the amount of power I use, and come up with ways to reduce my usage — and carbon footprint — dramatically.
What about fixed panels?
For fixed installations, my top tip is simple: keep your panels clean. Even a light dusting of pollen can reduce your solar harvesting by as much as 30%. Even a small smattering of leaves or other detritus rotting on your panels can cut efficiency by 50%.
Also: How my portable wind turbine compares to solar panels – 2 years of testing later
While cleaning, check for damage. Hail is a real danger, as are meteorites (yes, space rocks). If you live in an area prone to large hailstones, ensure your panels are rated to UL 61730 to withstand storm damage.
For extra protection, you can use a soft cover, spray on a methacrylate protector, or install a wire mesh over the panels to break up hailstones.
Closing thoughts
Getting the best from portable solar panels means combining some science with a bit of creativity, and lashings of adaptability.
Also: I was skeptical of this inflatable solar-powered lantern, but it’s become a staple
Whether you’re setting up an off-grid cabin, preparing for emergencies, or wanting to do your bit for the planet and reduce your carbon footprint, understanding how to optimize your setup will ensure you get the most out of your investment. And for those with fixed panels, a little maintenance goes a long way in keeping your system efficient and reliable.