If you were lucky enough to be near the path of totality, and didn’t have your view obscured by clouds, yesterday’s eclipse provided some very memorable views. But you know what’s even better than making memories? Having cold hard data to back it up.
Hackaday contributor [Bob Baddeley] was in Madison, Wisconsin for the big event, which NASA’s Eclipse Explorer website predicted would see about 87% coverage. Watching the eclipse through the appropriate gear at the local hackerspace was fun, but the real nerding out happened when he got home and could pull the data from his solar system.
A graph of the system’s generated power shows a very clear dip during the duration of the eclipse, which let him determine exactly when the occlusion started, peaked, and ended.
Recently, a company by former SpaceX employee Ben Nowack – called Reflect Orbital – announced that it is now ready to put gigantic mirrors in space to reflect sunshine at ground-based solar farms. This is an idea that’s been around for a hundred years already, both for purposes of defeating the night through reflecting sunshine onto the surface, as well as to reject the same sunshine and reduce the surface temperature. The central question here is perhaps what the effect would be of adding or subtracting (or both) of solar irradiation on such a large scale as suggested?
We know the effect of light pollution from e.g. cities and street lighting already, which suggests that light pollution is a strongly negative factor for the survival of many species. Meanwhile a reduction in sunshine is already a part of the seasons of Autumn and Winter. Undeniable is that the Sun’s rays are essential to life on Earth, while the day-night cycle (as well as the seasons) created by the Earth’s rotation form an integral part of everything from sleep- and hibernation cycles, to the reproduction of countless species of plants, insects, mammals and everyone’s favorite feathered theropods.
With these effects and the gigantic financial investments required in mind, is there any point to space-based mirrors?
Two things we love are economical solutions to problems, and clever ways to use things for other than their intended purpose. [CelGenStudios] hits both bases with a simple illuminated and spinning sign made from a lamp and a couple economical pieces of hardware: an LED bulb, and a solar-powered product spinner. Both are readily and cheaply available from your favorite overseas source.
The first step in making a cheap illuminated sign is to not buy one, but instead make do with a standing lamp. Plug a bright LED bulb into the socket, decorate the lampshade with whatever logos or signs one wishes to display, and one has an economical illuminated sign suitable for jazzing up a table at an event. But what really kicks it up a notch is making it rotate, and to do that is where the clever bit comes in.
Mounting the lampshade to the solar turntable body yields a simple, rotating, illuminated sign.
The first attempt used a BBQ rotisserie motor to turn the whole lamp, but it was too loud and not especially stable. The second attempt used a “disco ball effect” LED bulb with a motorized top; it worked but turned too quickly and projected light upward instead of into the lampshade.
The winning combination is LED bulb plus a little solar-powered turntable onto which the lampshade mounts. As a result, the lampshade spins slowly when the lamp is turned on. It might not be the most durable thing to ever come out of a workshop, but as [CelGenStudios] says, it only needs to last for a weekend.
The basic concept is far more simple than it might sound, so check it out in the video (embedded below) to see it in action. Curious about what’s inside those little solar spinners? Skip to 5:55 in the video to see how they work. And if you’re intrigued by the idea of using solar power for motive force but want to get more hands-on with the electrical part, we have just the resource for turning tiny motors with tiny solar cells.
A Pi Zero doesn’t need much to sustain itself, and it’s projects like the PhotonPower Zero that remind us of it its low appetite when we need this reminder most. The PhotonPower Zero board lets you power a Pi Zero board from a solar cell, with a LiIon backup, and a microcontroller for power management. Created by [David Murray], this board’s been a perfect solution for quite a few projects of his, and now he is sharing the design so that we can create outdoor-suited devices as easily as he’s been able to.
Tested for months in Australian summer and winter conditions alike, the design pulls no punches and has everything you might need. Like any self-respecting power addon, it has a management microcontroller for going as low-power as you’d like, communicating the battery data to the Pi Zero, and being able to safely shut it down when needed. If you fancy what this board does, [David Murray] tells you all, both in the video and in the associatedposts!
One of the best parts about this board is that it’s fully open-source – schematics, KiCad PCB source files, and even 3D designs are available in the GitHub repo. You could source all the parts right now and build a fleet of solar-powered Zeros, and if you want the hard parts to be done for you, there’s a Kickstarter campaign that lets you get a PhotonPower Zero board without self-assembly. We’ve covered similar boards before – powering a Pi Zero isn’t lost art, and, there’s a lot to learn from this project specifically. Such boards are especially tempting, given that the latest Pi Zero W 2 is the most efficient Pi Zero to date – outdoor-capable 24/7 powered devices with a fair bit of CPU have never been this close!
Perovskites hold enormous promise for generating solar energy, with the potential to provide lighter and cheaper cells than those made from silicon. Unfortunately, the material breaks down too rapidly to be practical for most applications. But thanks to some recent research, we now have a better understanding of the nanoscale changes that happen during this breakdown, and how to combat it.
The research is focused on the topic of passivation, which seeks to increase the useful lifespan of perovskites by studying the surface interface where they meet other materials. Most of the perovskite material is a perfect latticework of atoms, but this structure is broken at the surface. This atomically “jagged” interface introduces losses which only get worse over time. Currently, the best way to address this issue is to essentially seal the surface with a very thin layer of hexylammonium bromide.
While this technique significantly simplified the passivation process when it was discovered, the effect had yet to be adequately characterized to further advance the field. According to lead author, [Dane deQuilettes], “This is the first paper that demonstrates how to systematically control and engineer surface fields in perovskites.”
We love a good deal, especially when it comes to scavenging parts for projects. Cheap outdoor solar lights are more than just garden accessories; they’re a handy source of waterproof enclosures, solar panels and batteries. This is demonstrated by [Tavis], who turned one such light into a Meshtastic LoRa communication node.
Where there’s an antenna, there’s a radio
A nice feature on this specific $15 Harbor Breeze Solar LED is the roomy solar panel enclosure with integrated 18650 battery holder, allowing for easy battery swaps. [Tavis] was able to easily fit the RAKwireless modular dev board, and wire it into the light’s charging circuit. The cheap circuit is likely not the most efficient, but will probably get the job done. It’s always possible to just swap it out with a better charging board. [Tavis] also added an external antenna by using a panel-mount SMA pigtail connector.
The Meshtastic project is all about enabling text-only communications through LoRa-based mesh networks, built using off-the-shelf devices and development boards that won’t break the bank. The project has seen some incredible growth, with people all over the world setting up their own networks.
For obvious reasons, there has been a lot of interest in small-scale residential solar power systems lately. Even in my neck of the woods, where the sun doesn’t shine much from October to April, solar arrays are sprouting up on rooftops in a lot of local neighborhoods. And it’s not just here in suburbia; drive a little way out into the country or spend some time looking around in Google maps and it won’t take long to spy a sizable array of PV panels sitting in a field next to someone’s ranch house or barn.
Solar has gotten to the point where the expense of an installation is no longer a serious barrier to entry, at least if you’re willing to put in a little sweat equity and not farm the project out to a contractor. Doing it yourself requires some specialized tools and knowledge, though, over and above your standard suite of DIY skills. So, in the spirit of sharing hard-won knowledge, I decided to take the somewhat unusual step of writing up one of my personal projects, which has been in progress for a couple of years now and resulted in a solar power system that isn’t on a rooftop or a ground-mounted array at all, but rather is completely mobile: my solar trailer.
Hackaday contributor [Bob Baddeley] was in Madison, Wisconsin for the big event, which NASA’s Eclipse Explorer website predicted would see about 87% coverage. Watching the eclipse through the appropriate gear at the local hackerspace was fun, but the real nerding out happened when he got home and could pull the data from his solar system.
