Solar Hacks

204 Articles

Making Solar Cells

January 4, 2018 by 11 Comments

We will admit that it is unlikely you have enough gear in your basement to make a solar cell using these steps. However, it is interesting to see how a bare silicon wafer becomes a solar cell. If you’ve seen ICs going through fabrication, you’ll see a lot of similarities, but there are some differences.

The process calls for a silicon wafer, some ovens, spin coaters, photolithography equipment, and a dice saw, among other things. Oh, you probably also need a clean room. Maybe you should just buy your solar cells off the shelf, but it is still interesting to see how they are made.

Modern solar cells have some extra structures to improve their efficiency, but the cells in this video are pretty garden-variety. For example, some experimental cells use multiple layers of active devices, each tuned to absorb a different wavelength of light.

If you really want to make your own, there’s another process where you can start with some copper and wind up with a kind of solar cell that uses a copper-based semiconductor material. But don’t be fooled into thinking that making the silicon variety is totally out of reach to hackers, we’ve seen [Sam Zeloof] pull it off.

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AMSAT MPPT Goes To Infinity And Beyond

November 27, 2017 by 19 Comments

AMSAT, the Radio Amateur Satellite Corporation, joined forces with students from Rochester Institute of Technology to create a MPPT attached to a Fox-1B CubeSat. It successfully launched into orbit on November 18th strapped to the back of a Delta II rocket. This analog MPPT, or Maximum Power Point Tracker, is used for optimizing the draw of a power cell in correspondence to the output of solar panels on the 10cm x 10cm satellite. In a nutshell, this works by matching the voltage of the two together. If you haven’t gotten a chance to play around with one of these first hand, Hackaday’s own [Elliot Williams] wrote up a thorough explanation of the glorious MPPT’s efficiency.

This little guy is currently hurtling along in an orbit every 90 minutes. During each of these elliptical trajectories, the satellite undergoes brutal heating and cooling cycles. The team calculated that this package will undergo a total of 29,200 orbits around Earth during its 5 year mission. This means that there are 29,200 tests for it to crack — quite literally — under pressure. To add another level of difficulty, the undergrad team didn’t have funding for automated board assembly. This meant that they had to hand solder over 400 micro components onto this board, adding additional human error to be accounted for in the likelihood of a failure. But so far, this puppy is going strong. This truly shows the struggles that can be overcome with a little elbow grease, hard work, and plain ‘ole good engineering.

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Joan Feynman Found Her Place In The Sun

November 21, 2017 by 45 Comments

Google ‘Joan Feynman’ and you can feel the search behemoth consider asking for clarification. Did you mean: Richard Feynman? Image search is even more biased toward Richard. After maybe seven pictures of Joan, there’s an endless scroll of Richard alone, Richard playing the bongos, Richard with Arline, the love of his life.

Yes, Joan was overshadowed by her older brother, but what physicist of the era wasn’t? Richard didn’t do it on purpose. In fact, no one supported Joan’s scientific dreams more than he did, not even their mother. Before Richard ever illuminated the world with his brilliance, he shined a light on his little sister, Joan.

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Mendocino Motor Drives Cubicle Conversations

November 5, 2017 by 15 Comments

Mendocino motors are solar-powered electric motors that rely on pseudo-levitation.  The levitation comes from magnets mounted on either end of the shaft, which repel same-field magnets fixed below them into the base.  When light shines on the solar panels, current flows through connected magnet wire windings, creating an electromagnetic field that interacts with a large stationary magnet mounted underneath. These constantly repelling forces spin the shaft, and the gaps between the solar panels provide the on-off cycle needed to make it spin 360°.

As [Konstantin] discovered, building this simple motor and getting it to spin depends on a lot of factors. The number of windings, the weight of each solar panel, and the magnet sizes all figure in. [Konstantin]’s struggles are your gain, however. His Instructable takes the guesswork out of the tolerances and he designed a nice, open-source 3D-printed structure to boot.

You’re right, these motors can’t do much work. But it would definitely look cool on your desk and might even start a conversation or two. If not, whip up this little electromagnetic train.

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Quick And Easy Solar Hot Air Balloon

October 30, 2017 by 63 Comments

[Becky Stern] likes to harness the power of the Sun. Most of us will immediately think of solar cells and other exotic solar energy techniques. But [Becky] shows how to make a hot air balloon using nothing but tape and garbage bags.

The idea is quite simple. You form a large envelope from black trash bags and fill it with air. Becky does that by just running with it, tying it off, and topping off with a little manual blowing. Once the sun heats the black bag, it floats.

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A Solar Freakin’ Walkway

October 13, 2017 by 22 Comments

Looking to add a little pizzazz to your back garden? Are those strings of lights hung in the trees looking a little dated? Why not try lighting your garden path with DIY solar-powered pavers?

If [jfarro]’s project looks like a miniature version of the much-touted solar freakin’ roadways concept, rest assured that there are huge differences. For one, these lighted pavers actually work — trust me on this; I live not far from the demo site for the Solar Roadways and the degree to which it underwhelms cannot be overstated. Granted, a garden path is a lot simpler to engineer than a road, but many of the challenges remain.

Using recycled glass blocks that are usually reserved for walls and windows, [jfarro] figured out how to attach Neopixel rings to the underside and waterproof them with a silicone conformal coating. The 12 lighted pavers he built draw considerable current, so a 45-watt solar array with charge controller and battery were installed to power the pavers. An Arduino and a motion sensor control the light show when someone approaches; more complicated programs are planned.

Hats off the [jfarro] for taking on a project like this. We don’t often see builds where electrical engineering meets civil engineering, and even on a small scale, dealing with dirt, stone, and water presents quite a few challenges. Here’s hoping his project lasts longer than the Solar Roadways project did.

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Innovating A Backyard Solar Battery System

July 19, 2017 by 33 Comments

Ever on the lookout for creative applications for tech, [Andres Leon] built a solar powered battery system to keep his Christmas lights shining. It worked, but — pushing for innovation — it is now capable of so much more.

The shorthand of this system is two, 100 amp-hour, deep-cycle AGM batteries charged by four, 100 W solar panels mounted on an adjustable angle wood frame. Once back at the drawing board, however, [Leon] wanted to be able track real-time statistics of power collected, stored and discharged, and the ability to control it remotely. So, he introduced a Raspberry Pi running Raspbian Jessie Lite that publishes all the collected data to Home Assistant to be accessed and enable control of the system from the convenience of his smartphone. A pair of Arduino Deuemilanoves reporting to the Pi control a solid state relay powering a 12 V, 800 W DC-to-AC inverter and monitor a linear current sensor — although the latter still needs some tinkering. A in-depth video tour of the system follows after the break!

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