Solar Hacks

207 Articles

COTS Components Combine To DIY Solar Power Station

June 12, 2025 by 19 Comments

They’re marketed as “Solar Generators” or “Solar Power Stations” but what they are is a nice box with a battery, charge controller, and inverter inside. [DoItYourselfDad] on Youtube decided that since all of those parts are available separately, he could put one together himself.

The project is a nice simple job for a weekend afternoon. (He claims 2 hours.) Because it’s all COTS components, it just a matter of wiring everything together, and sticking into a box.  [DoItYourselfDad] walks his viewers through this process very clearly, including installing a shunt to monitor the battery. (This is the kind of video you could send to your brother-in-law in good conscience.)

Strictly speaking, he didn’t need the shunt, since his fancy LiFePo pack from TimeUSB has one built in with Bluetooth connectivity. Having a dedicated screen is nice, though, as is the ability to charge from wall power or solar, via the two different charge controllers [DoItYourselfDad] includes. If it were our power station, we’d be sure to put in a DC-DC converter for USB-PD functionality, but his use case must be different as he has a 120 V inverter as the only output. That’s the nice thing about doing it yourself, though: you can include all the features you want, and none that you don’t.

We’re not totally sure about his claim that the clear cargo box was chosen because he was inspired by late-90s Macintosh computers, but it’s a perfectly usable case, and the build quality is probably as good as the cheapest options on TEMU.

This project is simple, but it does the job. Have you made a more sophisticated battery box, or other more-impressive project? Don’t cast shade on [DoItYourselfDad]: cast light on your work by letting us know about it!. Continue reading “COTS Components Combine To DIY Solar Power Station” →

SkyRoof, A New Satellite Tracker For Hams

June 10, 2025 by 13 Comments

Communicating with space-based ham radio satellites might sound like it’s something that takes a lot of money, but in reality it’s one of the more accessible aspects of the hobby. Generally all that’s needed is a five-watt handheld transceiver and a directional antenna. Like most things in the ham radio world, though, it takes a certain amount of skill which can’t be easily purchased. Most hams using satellites like these will rely on some software to help track them, which is where this new program from [Alex Shovkoplyas] comes in.

The open source application is called SkyRoof and provides a number of layers of information about satellites aggregated into a single information feed. A waterfall diagram is central to the display, with not only the satellite communications shown on the plot but information about the satellites themselves. From there the user can choose between a number of other layers of information about the satellites including their current paths, future path prediction, and a few different ways of displaying all of this information. The software also interfaces with radios via CAT control, and can even automatically correct for the Doppler shift that is so often found in satellite radio communications.

For any ham actively engaged in satellite tracking or space-based repeater communications, this tool is certainly worth trying out. Unfortunately, it’s only available for Windows currently. For those not looking to operate under Microsoft’s thumb, projects such as DragonOS do a good job of collecting up the must-have Linux programs for hams and other radio enthusiasts.

Tracking The Sun? Nah!

May 7, 2025 by 43 Comments

If you want solar power, you usually have to make a choice. You can put a solar panel in a fixed location and accept that it will only put out the maximum when the sun is properly positioned. Or, you can make the panels move to track the sun.

While this isn’t difficult, it does add cost and complexity, plus mechanical systems usually need more maintenance. According to [Xavier Derdenback], now that solar panels are cheaper than ever, it is a waste of money to make a tracking array. Instead, you can build a system that looks to the east and the west. The math says it is more cost effective.

The idea is simple. If you have panels facing each direction, then one side will do better than the other side in the morning. The post points out that a tracking setup, of course, will produce more power. That’s not the argument. However, for a given power output, the east-west solution has lower installation costs and uses less land.

Continue reading “Tracking The Sun? Nah!” →

Solar Power, Logically

March 20, 2025 by 86 Comments

We’ve all seen the ads. Some offer “free” solar panels. Others promise nearly free energy if you just purchase a solar — well, solar system doesn’t sound right — maybe… solar energy setup. Many of these plans are dubious at best. You pay for someone to mount solar panels on your house and then pay them for the electricity they generate at — presumably — a lower cost than your usual source of electricity. But what about just doing your own set up? Is it worth it? We can’t answer that, but [Brian Potter] can help you answer it for yourself.

In a recent post, he talks about the rise of solar power and how it is becoming a large part of the power generation landscape. Interestingly, he presents graphs of things like the cost per watt of solar panels adjusted for 2023 dollars. In 1975, a watt cost over $100. These days it is about $0.30. So the price isn’t what slows solar adoption.

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Solar Planes Are Hard

October 12, 2024 by 12 Comments

A regular comment we see on electric aircraft is to “just add solar panels to the wings.” [James] from Project Air has been working on just such a solar plane, and as he shows in the video after the break, it is not a trivial challenge.

A solar RC plane has several difficult engineering challenges masquerading as one. First, you need a solid, efficient airframe with enough surface area for solar panels. Then, you need a reliable, lightweight, and efficient solar charging system and, finally, a well-tuned autopilot to compensate for a human pilot’s limited endurance and attention span.

In part one of this project, a fault in the electrical system caused a catastrophe so James started by benching all the electricals. He discovered the MPPT controller had a battery cutoff feature that he was unaware of, which likely caused the crash. His solution was to connect the solar panels to the input of a 16.7 V voltage regulator—just under the fully charged voltage of a 4S LiPo battery— and wire the ESC, control electronics, and battery in parallel to the output. This should keep the battery charged as long as the motor doesn’t consume too much power.

After rebuilding the airframe and flight testing without the solar system, [James] found the foam wing spars were not up to the task, so he added aluminum L-sections for stiffness. The solar panels and charging system were next, followed by more bench tests. On the test flight, it turned out the aircraft was now underpowered and struggled to gain altitude thanks to the added weight of the solar system. With sluggish control responses,[James] eventually lost sight of it behind some trees, which led to a flat spin and unplanned landing.

Fortunately, the aircraft didn’t sustain any damage, but [James] plans to redesign it anyway to reduce the weight and make it work with the existing power system.

We’ve seen several solar planes from [rctestflight] and meticulously engineered versions from [Bearospace Industrues]. If long flight times is primarily what you are after, you can always ditch the panels and  use a big battery for 10+ hour flights.

Continue reading “Solar Planes Are Hard” →

Pi Zero Power Optimization Leaves No Stone Unturned

October 3, 2024 by 17 Comments

If you’ve ever designed a battery-powered device with a Pi Zero, you have no doubt looked into decreasing its power consumption. Generic advice, like disabling the HDMI interface and the onboard LED, is omnipresent, but [Manawyrm] from [Kittenlabs] goes beyond the surface-level, and gifts us an extensive write-up where every recommendation is backed with measurements. Armed with the Nordic Power Profiler kit and an SD card mux for quick experimentation, she aimed at two factors, boot time and power consumed while booting, and made sure to get all the debug information we could use.

Thanks to fast experimentation cycles and immediate feedback, we learn plenty of new things about what a Pi Zero does and when, and how we can tame various power-hungry aspects of its behavior. Disabling the GPU or its aspects like HDMI output, tweaking features like HAT and other peripheral probing, and even tactical overclocking during boot – it’s an extensive look at what makes a Pi Zero tick, and no chance for spreading baseless advice or myths.

All in all, this write-up helps you decrease the boot time from twelve seconds to just three seconds, and slash the power budget of the boot process by 80%. Some recommendations are as simple as config.txt entries, while others require you to recompile the kernel. No matter the amount of effort you can put into power optimization, you’ll certainly find things worth learning while following along, and [Manawyrm]’s effort in building her solar-powered Pi setup will help us all build better Pi-Zero-powered solar devices and handhelds.

Hard Lessons Learned While Building A Solar RC Plane

September 9, 2024 by 17 Comments

Although not the first to try and build a DIY solar-powered remote control airplane, [ProjectAir]’s recent attempt is the most significant one in recent memory. It follows [rctestflight]’s multi-year saga with its v4 revision in 2019, as well as 2022’s rather big one by [Bearospace]. With so many examples to look at, building a solar-powered RC airplane in 2024 should be a snap, surely?

The first handicap was that [ProjectAir] is based in the UK, which means dealing with the famously sunny weather in those regions. The next issue was that the expensive, 20% efficient solar panels are exceedingly fragile, so the hope was that hot-gluing them to the foam of the airplane would keep them safe, even in the case of a crash. During the first test flights they quickly found that although the airplane few fairly well, the moment the sun vanished behind another cloud, the airplane would quite literally fall out of the sky, damaging some cells in the process.

Continue reading “Hard Lessons Learned While Building A Solar RC Plane” →