Plenty of us have experience with paper shredders, but there are all kinds of machines designed to completely destroy other materials as well, from metal and plastic, to entire cars. [Action BOX] built their own heavy-duty shredder capable of dismantling things like cell phones and other robust handheld objects, but after seeing what it would physically shred they decided to give it an actual job creating insulation for the attic space in their garage.
The shredder itself uses opposing metal plates arranged on sets of two cylinders, with each cylinder powered by it’s own large motor. In total, the entire system uses around 1.5 kW, so to make their green insulation project as green as possible they decided to power it with an equivalent amount of solar panels. For the insulation they’re using a year’s worth of boxes from various deliveries, and after a time-consuming process preparing the boxes for the shredder, shredding the strips of cardboard, and packaging it in garbage bags their efforts netted them enough to partially fill the space between four ceiling joists. Continue reading “DIY Shredder Creates Insulation”→
Solar power is an excellent way of generating electricity, whether that’s for an off-grid home or for the power grid. With no moving parts maintenance is relatively low, and the downsides of burning fuel are eliminated as well. But as much as it’s revolutionized power generation over the last few decades, there’s still some performance gains to be made when it comes to the solar cells themselves. A team at Stanford recently made strides in improving cell efficiency by bending the properties of sunlight itself.
In order to generate electricity directly from sunlight, a photon with a specific amount of energy needs to strike the semiconductor material. Any photons with higher energy will waste some of that energy as heat, and any with lower energy won’t generate electricity. Previous methods to solve this problem involve using something similar to a prism to separate the light out into colors (or energies) that correlate to specific types of cells calibrated specifically for those colors. This method does the opposite: it changes the light itself to an color that fits the semiconductor material. In short, a specialized material converts the energy from two lower-energy photons into a single higher-energy photon, which then strikes the solar panel to create energy.
By adding these color-changing materials as a layer to a photovoltaic solar panel, the panel can generate more energy with a given amount of light than a traditional panel. The major hurdle, as with any research, is whether or not this will be viable when produced at scale, and this shows promise in that regard as well. There are other applications for these materials beyond photovoltaics as well, and the researchers provide an excellent demonstration in 3D printing. By adding these color-change materials to resin, red lasers can be used instead of blue or ultraviolet lasers to cure resin in extremely specific locations, leading to stronger and more accurate prints.
If you attended the 2022 Supercon, you might have heard the story about the SMD soldering challenge table nearly catching on fire. A magnifying lamp caught the sun just right and burned a neat trench into another lamp’s plastic base. While disaster was averted, [Jelle Seegers] does this on purpose using a huge 5-meter lens to smelt metal.
The Design Academy Eindhoven student is participating in Dutch Design Week and built the machine which is able to manually track the sun to maximize the amount of solar energy applied to the metal.
The usual solar cell is made of silicon. The better cells use the crystalline form of the element, but there are other methods to obtain electric energy from the sun using silicon. Forming silicon crystals, though, can be expensive so there is always interest in different solar technologies. Perovskite is one of the leading candidates for supplanting silicon. Since they use lead salts, they are cheap and simple to construct. The efficiency is good, too, even when the material is not particularly well ordered. The problem is every model science has on what should make a good solar cell predicted that orderly compounds would perform better, even though this is not true for perovskite. Now scientists at Cambridge think they know why these cells perform even in the face of structural defects.
Perovskites take their name from a natural mineral that has the same atomic structure. In 2009, methylammonium lead halide perovskites were found to act as solar cells. Conversion rates can be as high as 25.5% according to sources and — apparently — the cells could be as much as 31% efficient, in theory. Solar cells top out — again, in theory — at 32.3% although in the real world you are lucky to get into the high twenties.
A company named Leap Photovoltaic claims they have a technology to create solar panels without silicon wafers which would cut production costs in half. According to [FastCompany] the cells are still silicon-based, but do not require creating wafers as a separate step or — as is more common — acquiring them as a raw material.
The process is likened to 3D printing as silicon powder is deposited on a substrate. The design claims to use only a tenth of the silicon in a conventional cell and requires fewer resources to produce, too.
Without knowing it, we’ve spent years watching [Jasper Sikken] piece together an empire of energy harvesting equipment, and now he’s putting the pieces together into wonderful creations. His recently finished solar harvesting pyramids are mesmerizing objects of geometric perfection we’d love to see glinting in the sun.
These solar harvesting pyramids are well described by their name. Each one contains a PCBA around 30mm on a side with a solar energy harvester built around the dedicated AEM10941 IC, a single solar cell, and a very bright green LED. [Jasper] calculates that the solar cell will charge the super capacitor at 20uA at with just 200 lux of light (a level typical for casual indoor spaces) letting it run indefinitely when placed indoors. Amazingly with the LED blinking for 15ms every 2 seconds it will run for 21 days in complete darkness. And that’s it! This is a software-free piece of hardware which requires no input besides dim light and blinks an LED indefinitely.
What about that super capacitor? It’s called a Lithium Ion Capacitor (LIC) and is a hybrid between a typical rechargeable lithium battery and an electrolytic capacitor, offering extremely high capacity in a convenient two leg through hole form factor. This one is a whopping 30 Farad at 3.8 V, and we first saw it when [Jasper] won the Hackaday Earth Day contest last month. Check out that link if you want to know more about their uses and how to integrate them.
For more detail about all of the components of the solar pyramid we need only turn to the Hackaday archives. In December 2019 [Tom Nardi] wrote about building a cheap degassing system for making some very familiar looking resin pyramids. And before that [Donald Papp] brought us another familiar piece of the pyramid when he wrote up a different 1″ x 1″ solar harvesting system that [Jasper] designed.
Check out the video after the break to see what one of these gems looks like from all sides. And for many more experiments leading up the final pyramid check out the logs on the Hackaday.io page.
When featuring cool hacks repurposing one thing for something else, we prefer to focus on what we could get our hands on and replicate for ourselves. Not this one, though, as nobody else has the misfortune of being responsible for 2,000 square kilometers (772 square miles) of radioactive contaminated land like the government of Ukraine. Trying to make the best of what they have, they’ve just launched a pilot program working to put up solar power farms inside the Chernobyl Exclusion Zone.
This is sure to invite some jokes in the comments section, but the idea has merit. Thirty years of weather has eroded the worst aftermath of the Chernobyl explosion. That area is no longer immediately lethal and people have been making short visits. Spanning from safety inspectors, to scientists, to curious adventurers with questionable judgement making television shows. Supposedly, by following rules on what not to do, it’s possible to keep radiation exposure of a short visit down to the level experienced by frequent fliers. But that’s still too much radiation for long-term stay. That means no homes, office parks, or factories. No agriculture either, as plants and animals grown in the area should not be eaten.
Well, next to the defunct power plant is the electric distribution infrastructure it used to feed into, and photovoltaic power generation requires little human oversight. Some maintenance will be required, but hopefully someone has worked out how to keep maintenance workers’ cumulative exposure to a minimum. And if this idea pans out, clean renewable energy would start flowing from the site of one of the worst ecological disasters of our era. That makes it a worthwhile hack on a grand scale.