The Dark Side Of Solar Power

Everybody loves solar power, right? It’s nice, clean, renewable energy that’s available pretty much everywhere the sun shines. If only the panels weren’t so expensive. Even better, solar is now the cheapest form of electricity for companies to build, according to the International Energy Agency. But solar isn’t all apples and sunshine — there’s a dark side you might not know about. Manufacturing solar panels is a dirty process from start to finish. Mining quartz for silicon causes the lung disease silicosis, and the production of solar cells uses a lot of energy, water, and toxic chemicals.

The other issue is that solar cells have a guanteed life expectancy of about 25 years, with average efficiency losses of 0.5% per year. If replacement begins after 25 years, time is running out for all the panels that were installed during the early 2000s boom. The International Renewable Energy Agency (IREA) projects that by 2050, we’ll be looking at 78 million metric tons of bulky e-waste. The IREA also believe that we’ll be generating six million metric tons of new solar e-waste every year by then, too. Unfortunately, there are hardly any measures in place to recycle solar panels, at least in the US.

How are solar panels made, anyway? And why is it so hard to recycle them? Let’s shed some light on the subject.

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CNC On The Desktop Hack Chat

Join us on Wednesday, August 26 at noon Pacific for the CNC on the Desktop Hack Chat with Matt Hertel and John Allwine!

Once limited to multi-million dollar machines on the floors of cavernous factories, CNC technology has moved so far downscale in terms of machine size that it’s often easy to lose track of where it pops up. Everything from 3D-printers to laser engravers use computer numeric control to move a tool to some point in three-dimensional space, and do it with unmatched precision and reproducibility.

CNC has gotten so pervasive that chances are pretty good that there’s a CNC machine of some sort pretty close to everyone reading this, with many of those machines being homebrew designs. That’s the backstory of Pocket NC, a company that was literally started in a one-bedroom apartment in 2011 by Matt and Michelle Hertel. After a successful Kickstarter that delivered 100 of their flagship five-axis desktop CNC mills to backers, they geared up for production and now turn out affordable machine tools for the masses. We’ve even seen some very complex parts made on these mills show up in projects we’ve featured.

For this Hack Chat, we’ll be joined by Pocket NC CTO and co-founder Matt Hertel and John Allwine, who recently joined the company as Principal Software Engineer. We’ll discuss not only Pocket NC’s success and future plans, but the desktop CNC landscape in general. Drop by with your questions regarding both the hardware and the software side of CNC, about turning an idea into a business, and where the CNC world and next-generation manufacturing will be heading in the future.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 26 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Open And Sustainable Engineering Hack Chat

Join us on Wednesday, August 19 at noon Pacific for the Open and Sustainable Engineering Hack Chat with Joshua Pearce!

Since the first of our hominid ancestors learned to pick up a rock and make it into a tool, we humans have been using our engineering skills to change the world. For most of the 2 million or so years since that first technological leap, natural materials like stone and wood were the focus of our engineering projects, and except for a few tantalizing remnants, most of what was built has returned to the Earth whence it came.

Then we discovered other materials; we learned to free metals from rocks and how to harvest the fossilized hydrocarbon remains of ancient plants. Iron, aluminum, plastic, and silicon became our stock in trade, and the planet is now layered so thick with these materials and the byproducts of harvesting them that a new geological epoch, the Anthropocene Epoch, has been proposed to cover this time of human activity and its impact on the geological record.

But if we humans are clever enough to make such an impact, we should be clever enough to think our way out of the mess, and wise enough to see the need. That’s where the efforts of Dr. Pearce’s research at the Michigan Tech Open Sustainability Technology (MOST) lab are focused. Dr. Pearce envisions a sustainable future powered by pervasive solar photovoltaic systems and using open-source technologies like 3D printing to drive new models for manufacturing. We’ve recently seen interesting work from his lab, like this grinder that makes custom compression screws for plastic recycling. The MOST page on Hackaday.io is filled with other great examples of the technology that supports their mission, from low-cost environmental testing instruments to 3D-printable microfluidics.

Dr. Pearce will join us on the Hack Chat to talk about open and sustainable engineering. Be sure to stop by with your questions and to find out what you can do to engineer a brighter future, starting right in your own shop.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, August 19 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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ESP32 Makes Great MPPT Controller In Low-Cost Solar Installation

Solar power projects have become, in general, a matter of selecting components like panels and batteries, hooking them together with industry-standard connectors, and sitting back to watch the free electricity flow. As such, solar projects have become a bit boring, so it’s not often we see one that attracts our attention the way this dirt-cheap open-source solar project does.

The backstory on [Tim O’Brien]’s DIY off-grid PV system starts with his desire to charge his eWheel, which amounts to a battery-powered standing unicycle. They look like a fun option for getting around an urban environment if you have the requisite degree of coordination, which we clearly lack. But charging something like that or an eBike is a great use case for solar, especially since [Tim] happened upon a 450W PV panel on the cheap. Sadly, the panel was a commercial unit, and compatible off-the-shelf MPPT, or maximum power-point tracking, controllers are expensive.

His solution was to build his own controller using a cheap DC-DC converter that just so happens to have serial remote control. An ESP32 monitors the panel voltage and controls the buck converter to run whatever he wants. When he’s not charging his eWheel, the system runs his laptop and router. As a bonus, the ESP32 talks to IoT services like Adafruit.io and Thingspeak, allowing him to track MPPT data without shipping it off to parts unknown.

While we appreciate a DIY MPPT controller and like [Tim]’s build, we feel like the documentation needs a bit of fleshing out. With solar installations, the devil is in the details, and not addressing seemingly mundane issues like cable routing and connector installation can lead to disaster.

Solar System Wars: Walmart Versus Tesla

It seems like hardly a day goes by that doesn’t see some news story splashed across our feeds that has something to do with Elon Musk and one or another of his myriad companies. The news is often spectacular and the coverage deservedly laudatory, as when Space X nails another double landing of its boosters after a successful trip to space. But all too often, it’s Elon’s baby Tesla that makes headlines, and usually of the kind that gives media relations people ulcers.

The PR team on the automotive side of Tesla can take a bit of a breather now, though. This time it’s Elon’s solar power venture, Tesla Energy Operations, that’s taking the heat. Literally — they’ve been sued by Walmart for rooftop solar installations that have burst into flames atop several of the retail giant’s stores. While thankfully no lives have been lost and no major injuries were reported, Walmart is understandably miffed at the turn of events, leading to the litigation.

Walmart isn’t alone in their exposure to potential Tesla solar problems, so it’s worth a look to see what exactly happened with these installations, why they failed, and what we as hackers can learn from the situation. As we’ll see, it all boils down to taking electrical work very seriously and adhering to standards designed to keep everyone safe, even when they just seem like a nuisance.

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Soak Up The Sun With This 3D Printed Solar Harvester

At first glance, adding solar power to your project might seem easy. Get a photovoltaic panel, point it towards the big ball of burning gas in the sky, and off you go. But in reality, there’s a bit more to it than that. Especially when you’re trying to do something on a small scale. Without a rooftop full of panels pumping out power, you’ve got to take what you can get.

If you’re looking to power small electronic devices such as sensors with a single solar panel, [Vadim Panov] has put together a very concise write-up and video on building a low-cost solar harvester. It combines a relatively small photovoltaic panel, a charging circuit, and a battery for energy storage into a easily mountable package. He’s provided all the details necessary to create your own version, all you have to do now is come up with the application for it.

As far as the electronics go, this project is about as straightforward as it gets. The three watt panel is connected up to a simplistic charging circuit, which in turn feeds into a single 18650 cell. You might be wondering why a charge controller is even necessary in such a simple set up. One problem is that the output voltage of the panel is higher than that of the battery. You also need a blocking diode that will prevent the battery from discharging into the cell during the night or in cloudy conditions.

While the electronics might seem elementary to some readers, we think the 3D printed case alone is worth taking a look at. Not only has [Vadim] come up with a design that perfectly encloses the fragile solar panel and associated electronics, but in the video after the break, he also explains how the entire thing can be made waterproof with an epoxy coating. As 3D prints can have a tendency to be porous, this technique is definitely something you should file away mentally if you’ve been thinking of deploying a printed enclosure outdoors.

Whether you’re looking to power environmental sensors for as near a century as is technically possible or a portable OpenWRT router for mobile anonymity, these small solar panels hold a lot of promise if you know how to work around their limitations.

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Solar Circuit Sculpture Pumms The Night Away

A word of warning: Google for the definition of the word “pummer” at your own risk. Rest assured that this beautiful solar-powered circuit sculpture fits the only definition of pummer that we care to deal with.

For the unfamiliar, a pummer is a device from the BEAM style of robotics, a sort of cyborg plant that absorbs solar energy during the day and turns it into a gently pulsating light that “pumms” away the dark hours.

[Mohit Bhoite]’s take on the pummer is an extraordinary model of a satellite executed mainly in brass rod. His attention to detail on the framework boggles our minds; we could work for days on a brass rod and never achieve the straight lines and perfect corners he did. The wings support two solar cells, while the hull of the satellite holds a dead-bugged 74HC240 octal buffer/line-driver chip and all the other pumm-enabling components. A one farad supercap – mounted to look like a dish antenna – is charged during the day and a single LED beacon blinks into the night.

No schematic is provided, but there are probably enough closeup shots to reverse engineer this, which actually sounds like a fun exercise. (Or you can cheat and fetch the PDF copy of the old Make magazine article that inspired him.)

Hats off to [Mohit] for a top-notch circuit sculpture. We’ve seen similarly detailed and well-executed sculptures from him before; something tells us this won’t be the last.

Thanks to [Varun Reddy] for the tip.