After Trucking Them Home, Old Solar Panels Keep On Trucking

The fact that there exist in our world flat rocks that make lightning when you point them at the sun is one of the most unappreciated bits of wizardry in this modern age. As hackers, we love all this of techno-wizardry-but some of us abhor paying full price for it. Like cars, one way to get a great discount is to buy used. [Backyard Solar Project] helped a friend analyze some 14-year-old panels to see just how they'd held up over the years, and it was actually better than we might have expected.

The big polycrystalline panels were rated at 235 W when new, and they got 6 of them for the low, low price of "get this junk off my property". Big panels are a bit of a pain to move, but that's still a great deal. Especially considering that after cleaning they averaged 180 W, a capacity factor of 77%. Before cleaning 14 years worth of accumulated grime cost about eight watts, on average, an argument for cleaning your panels. Under the same lighting conditions, the modern panel (rated to 200 W) was giving 82% of rated output.

That implies that after 14 years, the panels are still at about 94% of their original factory output, assuming the factory wasn't being overoptimistic about the numbers to begin with. Still, assuming you can trust the marketing, a half a percent power drop per year isn't too bad. It's also believable, since the US National Renewably Energy Laboratory (yes, they have one) has done tests that put that better than the average of 0.75 %/yr. Of course the average American solar panel lives in a hotter climate than [Backyard Solar Project], which helps explain the slower degradation.

Now, we're not your Dad or your accountant, so we're not going to tell you if used solar panels are worth the effort. On the one hand, they still work, but on the other hand, the density is quite a bit lower. Just look at that sleek, modern 200 W panel next to the old 235 W unit. If you're area-limited, you might want to spring for new, or at least the more energy-dense monocrystalline panels that have become standard the last 5 years or so, which aren't likely to be given away just yet. On the gripping hand, free is free, and most of us are much more constrained by budget than by area. If nothing else, you might have a fence to stick old panels against; the vertical orientation is surprisingly effective at higher latitudes.

#solarhacks #reuse #solarpanel #solarpower

Hard Lessons Learned While Building a Solar RC Plane https://hackaday.com/2024/09/09/hard-lessons-learned-while-building-a-solar-rc-plane/ #autonomousaircraft #solarairplane #SolarHacks #RCairplane #ardupilot

The Sunchronizer Keeps Your Solar Panel Aligned https://hackaday.com/2024/08/15/the-sunchronizer-keeps-your-solar-panel-aligned/ #linearactuator #solartracker #SolarHacks #singleaxis #solarpanel #elevation #ESP32 #solar

New Solar Spheres Claim to be Better than Solar Panels https://hackaday.com/2024/07/06/new-solar-spheres-claim-to-be-better-than-solar-panels/ #solarenergy #solarpanels #SolarHacks #News

Solar Energy Plant Creates Fuel https://hackaday.com/2024/06/29/solar-energy-plant-creates-fuel/ #solarenergy #SolarHacks #syngas

2024 Business Card Challenge: NoiseCard Judges the Sound Around You https://hackaday.com/2024/06/22/2024-business-card-challenge-noisecard-judges-the-sound-around-you/ #2024BusinessCardChallenge #Microcontrollers #STM32G031J6 #SolarHacks #contests #noise #solar #stm32

Garden Light Turned Mesh Network Node https://hackaday.com/2024/01/21/garden-light-turned-mesh-network-node/ #WirelessHacks #gardenlight #SolarHacks #Meshtastic #solar #LoRa

Sun on the Run: Diving into Solar with a Mobile PV System https://hackaday.com/2024/01/17/sun-on-the-run-diving-into-solar-with-a-mobile-pv-system/ #chargecontroller #photovoltaic #OriginalArt #SolarHacks #Interest #combiner #inverter #lithium #offgrid #trailer #mobile #solar #MC-4 #mppt #pv

Desalinating Water With the Sun https://hackaday.com/2023/12/21/desalinating-water-with-the-sun/ #ShanghaiJiaoTongUniversity #desalination #passivesolar #greenhacks #SolarHacks #cleanwater #plumbing #seawater #pumps #solar #water #mit

Robot Sunflower Follows the Sun https://hackaday.com/2023/11/03/robot-sunflower-follows-the-sun/ #ArduinoHacks #SolarHacks #suntracker #sunflower #servo

Wireless Data Connections Through Light https://hackaday.com/2023/08/25/wireless-data-connections-through-light/ #datatransmission #visiblelight #SolarHacks #solarcell #lighting #wireless #li-fi #solar #led

The Mysterious Case of the Disappearing Inventor https://hackaday.com/2023/08/19/the-mysterious-case-of-the-disappearing-inventor/ #SolarHacks #solarpanel #solarcell #history #News

2023 Hackaday Prize: A Reinvented Solar Tracker https://hackaday.com/2023/08/09/2023-hackaday-prize-a-reinvented-solar-tracker/ #2023HackadayPrize #TheHackadayPrize #renewableenergy #solartracker #greenhacks #SolarHacks #solarpanel

Move Aside Solar, We’re Installing An Algae Panel

[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.

#greenhacks #solarhacks #algae #algaepanel #biomass #solar

LEGOpunk Orrery Knows Just the Right Technics

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](https://rebrickable.com/mocs/MOC-88534/marian/sun-earth-moon-orrery/#details).

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.

#solarhacks #earth #lego #legotechnic #moon #orrery #sun #technic

BEAM Bird Pendant Really Chirps

[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.

#solarhacks #0603 #beam #beamrobotics #solarpower

Perovskites Understood

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.

Using advanced microscopy, the team found that there were two different types of disorders occurring in the material. Electrical disorganization reduces the solar energy conversion performance. However, a corresponding chemical disorder is actually advantageous for efficiency and more than makes up for the electrical disadvantage.

The researchers hope this will offer new insights into how to create even better perovskite materials for use in the solar cells of the future. We've seen this material used for things other than solar cells. There is a lot of research activity centering on these cells, so we hope to see some practical applications, soon.

[Main image: Alex T. at Ella Maru Studios via University of Cambridge research announcement]

#science #solarhacks #perovskites #solarcells #solarenergy

Solar Cells, Half Off

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.

This sounds a lot like amorphous silicon cells which have been around for a while. We assume the trick is they've found a cheaper way to produce them using off-the-shelf equipment. These cells are typically lower in performance than crystalline cells. We don't know if Leap has a way to improve the solar cell's output.

Where can you get them? Not so fast. Plans are to have pilot production in 2023 with widespread availability by 2024. If the cells do produce less power per unit area, their success will depend on cutting costs so that a bigger unit is cheaper than a smaller crystalline panel. Even then, in some applications surface area matters.

The again, not all solar cells use silicon at all. You can even make some of them yourself.

#news #solarhacks #photovoltaic #silicon #solarcell #solarcells #solarenergy

Solar Power Goes Back to 1910 Tech

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%.

Of course, 5% doesn't sound so great today. But to put it in context, the original Bell solar cells in 1954 had about 6% efficiency. Oddly enough, Cove didn't set out to build solar electric generators. He was actually trying to build a thermoelectric generator to produce electricity from a wood stove.

His design used metal plugs in an asphalt substrate. One end of the three-inch plugs would get hot while the other was meant to stay cool. The temperature difference ought to create a bit of electricity and with almost 1,000 plugs in the 1.5 square meter panel, there would be enough to do something useful.

Or so Cove thought. Some early devices generated some power when exposed to heat. But changes to the plug composition caused the device to quit working when exposed to heat. However, sunlight through a violet glass did work and worked significantly better than before. Cove couldn't explain why, but we can see that Cove had stumbled onto a metallic semiconductor, not unlike a modern Schottky junction. The plugs were zinc and antimony -- something used in modern semiconductor processing -- and were capped on one end with a nickel, copper, and zinc alloy and on the other end with copper.

The article goes on to point out that simple metal solar panels could be cheaper to produce and easier to recycle. Of course, you'd need to work on getting the efficiency way up to match modern cells.

There is one disclaimer. Apparently, Cove is relatively unknown and while he has a patent issued in 1906 the patent has some misleading information in it. Add to that he was supposedly kidnapped (the police thought it was a hoax) and he spent a year in jail for stock manipulation. We don't know how much of Cove's story is true or not -- apparently [Decker] received research from a reader, but it all sounds plausible enough.

We keep hearing about alternate solar cell materials, but silicon is still the standard to beat. Most do-it-yourself panels start with a cell, but using this low-tech method could let you produce the whole thing.

#solarhacks #history #solarcell #solarpanel