A Solar Frame From Scratch

June 6, 2022 by Matthew Carlson 14 Comments

“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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Move Aside Solar, We’re Installing An Algae Panel

February 7, 2022 by Matthew Carlson 58 Comments

[Cody] of Cody’sLab has been bit by what he describes as the algae growing bug. We at Hackaday didn’t know that was a disease floating around, but we’ll admit that we’re not surprised after the last few years. So not content to stick to the small-time algae farms, [Cody] decided to scale up and build a whole algae panel.

Now, why would you want to grow algae? There are edible varieties of algae, you can extract oils from it, and most importantly, it can be pumped around in liquid form. To top it off, all it needs is just sunlight, carbon dioxide, and a few minerals to grow. Unlike those other complicated land-based organisms that use photosynthesis, algae don’t need to build any structure to hold themselves up or collect sunlight; it floats.

The real goal of the algae is to build a system known as “Chicken Hole.” The basic idea is to have a self-sufficient system. The algae feed the insects, the insects feed the chickens, and so on up the chain until it reaches [Cody]. While glass would make an ideal material for the algae tubes, plastic soda bottles seem like a decent proxy for a prototype and are much cheaper. He connected around 100 half-liter bottles to form long tubes and a PVC distribution system. The algae needs to be pumped into an insulated container to prevent it from freezing at night. At first, a simple timer outlet controlled the pump to only run during the day, draining it via gravity at night. However, the algae can’t heat up enough when running on cloudy, cold winter days, and it cools off. A solar panel and a temperature sensor form the logic for the pump, with a minimum temperature and sunlight needed to run.

[Cody] mentions that he can expect around 10 grams of algae per day on a panel this size in the winter. He’s going to need quite a few more if he’s going to scale up properly. Perhaps in the future, we’ll see panels growing algae robots? Video after the break.

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LEGOpunk Orrery Knows Just The Right Technics

January 6, 2022 by Ryan Flowers 6 Comments

Is the unmistakable sound of the shuffling of LEGO pieces being dug through burned into your psyche? Did the catalog of ever more complex Technic pieces send your imagination soaring into the stratosphere and beyond? Judging by the artful contraption in the video below the break, we are fairly certain that [Marian] can relate to these things.

No doubt inspired by classic orreries driven by clockwork, [Marian]’s LEGO Sun-Earth-Moon orrery is instead driven by either hand cranks or by electric motors. The orrery aims to be astronomically correct. To that end, a full revolution of a hand crank produces a full day’s worth of movement.

Solar and lunar eclipses can be demonstrated, along with numerous other principals such as the tilt of the earth, moon phases, tidal locking, and more, which can be found at the project page.

While classical orreries predate the Victorian era, there seems to be an almost inexplicable link between orreries and the Steampunk aesthetic. But [Marian]’s orrery brought the term “LEGOpunk” to mind. Could it be? Given that there are 2305 pieces and 264 pages of instructions with 436 steps, we think so!

We’ve covered just a few orreries in the past, from this somewhat simple laser cut orrery to this horrifically complex and beautiful thing here. Continue reading “LEGOpunk Orrery Knows Just The Right Technics” →

Solar-powered pendant chirps like a bird.

BEAM Bird Pendant Really Chirps

December 9, 2021 by Kristina Panos 16 Comments

[NanoRobotGeek] had a single glorious weekend between the end of the term and the start of exams. Did they buy a keg and party it up? No, in fact, quite the opposite — they probably gained a few brain cells by free-form soldering this beautiful chirping bird pendant at 0603 instead.

The circuit is a standard BEAM project built around a 74HC14, but [NanoRobotGeek] made a few changes to achieve the ideal chirp sound. As you can see in the video after the break, it chirps for around 30 seconds and then shuts off for 1-2 minutes before starting up again.

What is better than a BEAM project? A portable one, we say. Although the chirping would probably get old pretty quickly, there’s just no substitute for working so small that you can carry it around your neck and show it off.

This one is kind of a long time coming, because [NanoRobotGeek] started by breadboarding the circuit and then made a PCB version way back in 2019, which they were attempting to miniaturize with this project. We think they did a fantastic job of it, and the documentation is stellar if you are crazy enough to attempt this one. You will need a lot of blu tack and patience, and pre-tinning is your friend. Be sure to check out the demo after the break.

The name checks out, and this isn’t [NanoRobotGeek]’s first foray into tiny circuit sculpture — just take a look at all we’ve covered.

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Perovskites Understood

November 27, 2021 by Al Williams 9 Comments

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.

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Solar Cells, Half Off

November 6, 2021 by Al Williams 34 Comments

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.

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Solar Power Goes Back To 1910 Tech

October 13, 2021 by Al Williams 41 Comments

If you want to read about a low-tech approach to solar cells invented — and forgotten — 40 years before Bell Labs announced the first practical silicon solar cell, we can’t promise the website, Low Tech Magazine, will be available. Apparently the webserver it is on is solar-powered, and a disclaimer mentions that it sometimes goes offline.

The article by [Kris De Decker] tells of George Cove and includes a picture from 1910 of the inventor standing next to what looks suspiciously like a solar panel (the picture above is from a 1909 issue of Technical World Magazine). His first demonstration of the technology was in 1905 and there is a picture of another device from 1909 that produced 45 watts of power using 1.5 square meters with a conversion efficiency of 2.75%. That same year, a new prototype had 4.5 square meters and used its 240-watt output to charge 5 lead-acid batteries. The efficiency was about 5%.

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