A Solar Frame From Scratch

“From scratch” is a bit of a murky expression. How scratchy does it get? Are you just baking your bread yourself or are you growing your own wheat? Rolling your own solar installation probably doesn’t involve manufacturing your own photovoltaic cells. But when it comes to making the frame to hold your panels, why not machine your own brackets and harvest the wood from trees nearby?. That’s what [Kris Harbour] did with his over-engineered 8.4kW solar stand.

He already had a wind turbine and a few solar panels elsewhere on the property, but [Kris] wanted a bit more power. At the start of the video, [Kris] makes an offhand comment that he wants this to last 30-40 years at a minimum. Everything from the focus on the concrete footings to the oversized brackets and beams reflects that. The brackets were cut on his plasma CNC and the wood was cut to rough dimensions using a sawmill on his property. He admits that the sapwood will rot away a bit after 20ish years, but since the core of the posts is heartwood, structurally they’ll last a long time. After planing down to the right size, cutting hole and grooves was a bit of an involved procedure. The structure is quite tall once erected and we loved watching it come together. The most impressive thing here is that this structure was put together by just a single person. All the rafters were cut and hand-chiseled to the right sizes and hoisted into place. The panels ultimately weren’t delivered on time and he had to switch to using new panels rather than the used panels he was expecting.

Previously, [Kris] had shown off his impressive hydroelectric setup. We’re looking forward to seeing the new solar array power all the projects [Kris] is planning in the future. Video after the break.

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Hackaday Links: May 22, 2022

It looks like it’s soon to be lights out for the Mars InSight lander. In the two years that the lander has been studying the geophysics of Mars from its lonely post on Elysium Planitia, InSight’s twin solar arrays have been collecting dust, and now are so dirty that they’re only making about 500 watt-hours per sol, barely enough to run the science packages on the lander. And that’s likely to worsen as the Martian winter begins, which will put more dust in the sky and lower the angle of the Sun, reducing the sunlight that’s incident to the panels. Barring a “cleaning event” courtesy of a well-placed whirlwind, NASA plans to shut almost everything down on the lander other than the seismometer, which has already captured thousands of marsquakes, and the internal heaters needed to survive the cold Martian nights. They’re putting a brave face on it, emphasizing the continuing science and the mission’s accomplishments. But barely two years of science and a failed high-profile experiment aren’t quite what we’ve come to expect from NASA missions, especially one with an $800 million price tag.

Closer to home, it turns out there’s a reason sailing ships have always had human crews: to fix things that go wrong. That’s the lesson learned by the Mayflower Autonomous Ship as it attempted the Atlantic crossing from England to the States, when it had to divert for repairs recently. It’s not clear what the issue was, but it seems to have been a mechanical issue, as opposed to a problem with the AI piloting system. The project dashboard says that the issue has been repaired, and the AI vessel has shoved off from the Azores and is once more beating west. There’s a long stretch of ocean ahead of it now, and few options for putting in should something else go wrong. Still, it’s a cool project, and we wish them a fair journey.

Have you ever walked past a display of wall clocks at the store and wondered why someone went to the trouble of setting the time on all of them to 10:10? We’ve certainly noticed this, and always figured it had something to do with some obscure horological tradition, like using “IIII” to mark the four o’clock hour on clocks with Roman numerals rather than the more correct “IV”. But no, it turns out that 10:10 is more visually pleasing, and least on analog timepieces, because it evokes a smile on a human face. The study cited in the article had volunteers rate how pleasurable watches are when set to different times, and 10:10 won handily based on the perception that it was smiling at them. So it’s nice to know how easily manipulated we humans can be.

If there’s anything more pathetic than geriatric pop stars trying to relive their glory days to raise a little cash off a wave of nostalgia, we’re not sure what it could be. Still, plenty of acts try to do it, and many succeed, although seeing what time and the excesses of stardom have wrought can be a bit sobering. But Swedish megastars ABBA appear to have found a way to cash in on their fame gracefully, by sending digital avatars out to do their touring for them. The “ABBA-tars,” created by a 1,000-person team at Industrial Light and Magic, will appear alongside a live backing band for a residency at London’s Queen Elizabeth Olympic Park. The avatars represent Benny, Bjorn, Agnetha, and Anni-Frid as they appeared in the 1970s, and were animated thanks to motion capture suits donned while performing 40 songs. It remains to be seen how fans will buy into the concept, but we’ll say this — the Swedish septuagenarians look pretty darn good in skin-tight Spandex.

And finally, not that it has any hacking value at all, but there’s something shamefully hilarious about watching this poor little delivery bot getting absolutely wrecked by a train. It’s one of those food delivery bots that swarm over college campuses these days; how it wandered onto the railroad tracks is anyone’s guess. The bot bounced around a bit before slipping under the train’s wheels, with predictable results once the battery pack is smooshed.

Hackaday Prize 2022: Glass Tube Solar Thermionic Converters

Typically, if you want to convert solar energy into electrical energy, you use either photovoltaic (PV) cells, or you use the sunlight to create steam to turn a turbine. Both of these methods are well-established and used regularly in both small- and grid-scale applications. However, [Nick Poole] wanted to investigate an alternative method, using thermionic converters for solar power generation.

[Nick] has been gearing up to produce various styles of vacuum tubes, and noted that the thermionic effect that makes them work could also be used to generate electricity. They are highly inefficient and produce far less power than a photovoltaic solar cell, meaning they’re not in common use. However, as [Nick] notes, unlike PV cells etched in silicon, a thermionic converter can be built with basic glassworking tools, requiring little more than a torch, a vacuum pump, and a spot welder.

Experiments with a large lens to focus sunlight onto a 6V3A diode tube showed promise. [Nick] was able to generate half a volt, albeit at a tiny current, with the design not being optimized for thermionic conversion. Further experiments involved electrically heating a pair of diode tubes, which was able to just barely light an LED at 1.7 V and a current of 7.5 uA. The conversion efficiency was a lowly 0.00012%, around 5 orders of magnitude worse than a typical PV cell.

[Nick]’s hope is that he can produce a tube designed specifically to maximize thermionic conversion for energy generation purposes. It’s likely there is some low-hanging fruit in terms of gains to be made simply by optimizing the design for this purpose, even if the technique can’t compete with other solar generation methods.

In any case, we’re eager to see what [Nick] comes up with! We love to see makers building tubes in their own home workshops.

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2022 Hackaday Prize: Get Your Planet-Friendly Power On!

Time flies! This weekend marks the end of the first stage of the 2022 Hackaday Prize, and your chance to enter your alternative-energy projects. There are ten $500 prizes up for grabs, and there’s still time to whip up a project page over on Hackaday.io to showcase it.

In this round, we’re looking for projects that harvest their own energy — solar, wind, heat, vibration, you name it — or projects that make it easier to collect, store, or use renewable energy. Whether this is microwatts or megawatts, the scale of the project is up to you! As long as it’s using or making it easier to use clean energy, we want to see it.

So far, we’ve seen some great projects, ranging from a optimizes the tilt angle of a home solar installation to a demonstration of using a new type of lithium-ion capacitor to add solar power to smaller projects. We really love [MartMet]’s simple Bluetooth thermometer hack, which adds a supercapacitor and solar cell to an outdoor thermometer, and then uses hacked firmware to log the charge status over a year of use! We’re suckers for good data.

The sun is not the only game in town, though. There are a surprising number of projects based on human energy production in emergency situations, from cranking to shaking. Thermionic converters were new to us, but we love explorations of fringe tech. Other traditional favorites like wind and water may make more sense for larger applications. And don’t forget how you’re going to store all this juice you’ve collected.

In short, we’ve got a bunch of great entries, but we’re still missing yours! There’s no minute like the last minute: if you’ve done some work in clean or renewable energy, set yourself up a Hackaday.io project page now. You’ll help make all our projects cleaner, and stand a good chance of taking home some real money to boot!

Once we’ve handled power, the next round is “Reuse, Recycle, Revamp” where any tech that uses recycled parts or facilitates reuse, repair, or recycling is fair game!

No-Laser CNC Engraver Is Something New Under The Sun

Hooking up a laser to a CNC gantry isn’t exactly an Earth-shattering innovation, but it does make for a useful tool. Even a cheap diode laser mounted to an old 3D printer can do engraving, marking, or even light-duty cutting. But what about a laser engraver without the laser? Can that be of any use?

Apparently, the answer is yes, if you can harness the power of the sun. That’s what [Lucas] did with his solar-tracking CNC engraver, the build of which is shown in the video below. The idea is pretty simple — mount a decent-sized magnifying lens where the laser optics would normally go on a laser engraver, and point the thing at the sun. But as usual, the devil is in the details. The sun has a nasty habit of moving across the sky during the day, or at least appearing to, so [Lucas] has to add a couple of extra degrees of freedom to a regular X-Y CNC rig to track the sun. His tracking sensor is simplicity itself — four CdS photocells arranged with a pair of perpendicular shades, and an Arduino to drive the gimbals in the correct direction to keep all four sensors equally illuminated. He had some initial problems getting the jerkiness out of the control loop, but the tracker eventually kept the whole thing pointing right at the Sun.

So how does it work? Not bad, actually — [Lucas] managed to burn some pretty detailed designs into a piece of wood using just the sun. He mentions adding a shutter to douse the cutting beam to allow raster patterns, but even better might be a servo-controlled iris diaphragm to modulate beam intensity and control for varying sun conditions. He might also check out this solar engraver we covered previously for some more ideas, too.

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Great Beginnings: The Antikythera Mechanism Gets A “Day Zero”

When an unknown genius sat down more than 2,000 years ago to design and build an astronomical instrument, chances are good that he or she didn’t think that entire academic institutions devoted to solving its mysteries would one day be established. But such is the enduring nature of the Antikythera mechanism, the gift from antiquity that keeps on giving long after being dredged up from a shipwreck in the Aegean Sea.

And now, new research on the ancient mechanism reveals that like other mechanical calendars, the Antikythera mechanism has a “day zero,” or a minimum possible date that it can display. The analysis by a team led by [Aristeidis Voulgaris] gets deep into the weeds of astronomical cycles, which the mechanism was designed to simulate using up to 37 separate gears, 30 of which have been found. The cycle of concern is the saros, a 223 lunar month cycle of alignments between the Earth, Sun, and Moon. The saros can be used to predict eclipses, astronomical events of immense importance in antiquity, particularly annular eclipses, which occur when the Moon is at apogee and therefore eclipses less of the Sun’s surface.

The researchers looked at historical annular eclipse data and found that saros cycle 58 had a particularly long annular eclipse, on 23 December 178 BCE. The eclipse would have been visible at sunrise in the eastern Mediterranean, and coupled with other astronomical goodies, like the proximity to the winter solstice, the Sun entering Capricorn, and the Moon being new and at apogee, was probably so culturally significant to the builder that it could serve as the initial date for calibrating all the mechanisms pointers and dials.

Others differ with that take, of course, saying that the evidence points even further back, to a start date in the summer of 204 BCE. In any case, if like us you can’t get enough Antikythera, be sure to check out our overview of the mechanism, plus [Clickspring]’s exploration of methods perhaps used to build it.

Hackaday Prize 2022: Solar Harvesting Is Better With Big Capacitors

The sun is a great source of energy, delivering in the realm of 1000 watts per square meter on a nice clear day. [Jasper Sikken] has developed many projects that take advantage of this power over the years, and has just completed his latest solar harvesting module for powering microcontroller projects.

The concept is simple. A small solar panel is used to charge up a lithium ion capacitor (LIC), which can then be used to power other projects. We first saw this project last year, when it was one of the winners of Hackaday’s 2021 Earth Day contest. Back then, it was only capable of dishing out 80 mA at 2.2V.

However, the latest version ups the ante considerably, delivering up to 400 mA at 3.3V. This opens up new possibilities, allowing the module to power projects using technologies like Bluetooth, WiFi and LTE that require more current to operate. It relies on a giant 250 F capacitor to store energy, and a AEM10941 solar energy harvesting chip to get the most energy possible out of a panel using Maximum Power Point Tracking (MPPT).

It’s a useful thing to have for projects that you’d like to run off the sun, and you can score one off Tindie if you don’t want to build your own. We’ve seen [Jasper] pull off other neat solar-powered projects before, too. Video after the break.

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