green hacks

809 Articles

Engineers: Be Subversive To Be Green

October 7, 2022 by 153 Comments

The caterers for the volunteer workforce behind the summer’s MCH hacker camp in the Netherlands served all-vegan food. This wasn’t the bean sprouts and lentils that maybe some of the more meat-eating readers might imagine when confronted with vegan food, nor was it a half-as-good array of substitutes with leathery soy hamburgers and rubbery fake cheese smelling suspiciously of feet.

Instead it was a well-crafted, interesting, and tasty menu that was something to look forward to after several hours driving a vanload of handwashing sinks. It was in one of their meals that I found food for thought when driving a week later past the huge Garzweiler open-cast lignite mine on my way through Germany to Luxembourg’s Haxogreen as part of my European hacker camp summer tour.

The meal was deep-fried soy protein strips and the mine is probably one of Western Europe’s dirtiest and most problematic CO2 sources in a country that likes to imagine itself as environmentally friendly, so where in this unlikely connection did I find a pairing? Continue reading “Engineers: Be Subversive To Be Green” →

Fermenter on the desk, with the front door opened and some tempeh disks visible inside of it

Hackaday Prize 2022: An Easy-To-Build Fermenter For Tempeh

October 3, 2022 by 18 Comments

[Maud Bausier] and [Antoine Jaunard] believe we should all know about tempeh — a traditional Indonesian food made out of legumes fermented with fungi. To simplify the process a bit: you get some soybeans, add a tempeh starter fungi culture to them, ferment them a while, and out comes the tempeh. It’s a great source of proteins that’s relatively easy to grow on your own. One catch, though — you do need a certain kind of climate to have it develop properly. This is why [Maud] and [Antoine] are bringing a tempeh fermenter design to this year’s Hackaday Prize.

Ready tempeh disks cut into long pieces, showing the cross-section of some. It looks pretty tasty!This fermenter’s controller drives a heating element, which adheres to a pre-programmed fermentation cycle. It also has a fan for airflow and keeping the heat uniform.

The fermenter itself is a small desktop machine with a laser-cut case helped by some CNC-cut and 3D-printed parts, electronics being a simple custom PCB coupling a Pi Pico with widely-available modules. This is clearly a project for someone with access to hackerspace or fab lab resources, but of course, all of the files are on GitHub.

Once built, this design allows you to grow tempeh disks in home conditions on a small scale. It seems the design is mostly finalized, but if you’d like to hear news about this project, they have a blog and a Mastodon feed with some recent updates.

We’ve covered a whole lot of fermentation-related hacks over these years. Most of them have been alcohol-related, but every now and then we see people building fermentation equipment for other food materials, like vinegar, yogurt and sourdough. Now, having seen this fermenter, we’ve learned of one more food hacking direction to explore. This project is one of 10 finalists for our latest Hackaday Prize round, Climate-Resilient Communities. It’s a well-deserved win, and we can’t wait to see where it goes!

Empty Spools Make Useful Tools, Like Counters

September 25, 2022 by 2 Comments

What’s the deal with getting things done? There’s a Seinfeld anecdote that boils down to this: get a calendar, do a thing, and make a big X on each day that you do the thing. Pretty soon, you’ll thirst for chains of Xs, then you’ll want to black out the month. It’s solid advice.

[3D Printy] likes streaks as well, and made several resolutions at the beginning of 2022. As the first of 30 videos to be made throughout the year, they featured this giant 3D printed counting mechanism (video, embedded below) that uses empty filament spools, some 3D prints, and not much else. These are all Hatchbox spools, and it won’t work for every type, but the design should scale up and down to fit other flavors.

This isn’t [3D Printy]’s first counter rodeo — he’s made several more normal-sized ones and perfected a clever carryover mechanism in the process, which is of course open-source. So each spool represents a single digit, and there are printed parts in the core that make the count carry over to the next spool. Whereas the early counters used threaded rod, this giant version rides on 2.5 mm smooth rod, so the spools can slide apart easily. But how does everything stay together? A giant elastic band made of TPU filament, of course — because the answer is always in the room.

Check out the video after the break, and stay for the 900%-sped-up assembly at the end.

Continue reading “Empty Spools Make Useful Tools, Like Counters” →

Giving Environmental Readouts Some Personality

September 25, 2022 by 4 Comments

Air Quality Index for one’s region can be a handy thing to know, but it’s such a dry and humorless number, isn’t it? Well, all that changes with [Andrew Kleindolph]’s AQI Funnies: a visual representation of live AQI data presented by a friendly ghost character in a comic panel presentation. The background, mood, and messaging are all generated to match the current conditions, providing some variety (and random adjectives) to spruce things up.

We love the attention paid to the super clean presentation, and the e-paper screen looks fantastic. Inside the unit is a Raspberry Pi using Python to talk to the AirNow.gov API to get local conditions and update every four hours (AirNow also has a number of useful-looking widgets, for those interested.)

The enclosure is 3D printed, and [Andrew] uses a Witty Pi for power management and battery conservation. The display is a color e-paper display that not only looks great, but has the advantage of not needing power unless the display is updating. The Pi can be woken up to update the screen with new info when needed, but otherwise can spend its time asleep.

[Andrew] has a knack for friendly presentations of information with an underlying seriousness, as we saw with his friendly reminders about nasty product recalls.

A hand holds a round disc of noodles wrapped in a translucent film with herb specs embedded in it.

Reimagined Ramen Comes In Edible Package

September 15, 2022 by 31 Comments

Hackers and college students alike reach for ramen when they want to fuel up on a budget, but, if you’re concerned about packaging waste, the plastic film and foil packets start to weigh on your conscience. [Holly Grounds] was sick of this compromise and came up with a way to have your packaging and eat it too.

[Holly] first experimented with different bioplastics until she developed a recipe for “an edible, tasteless starch-based bioplastic, that dissolves in contact with boiling water.” With that accomplished, she next integrated flavoring into the bioplastic wrapper so that there’s no foil packet. She found that herbs and spices worked, but larger solids like shrimp couldn’t be incorporated into the film.

For the finishing touch, she fashioned the noodles into a disk so they fit better in a bowl for cooking. To cook the noodles, you remove a puck from the wax paper sleeve holding multiple servings, add boiling water, stir, and enjoy. [Holly] says that her ramen packets are quicker to prepare than existing packets since there are fewer steps and the shape is optimized for cooking. That’s a win-win for the planet and convenience.

If you want to see another pasta packaging marvel, we’ve previously covered Flat Pack Pasta. Have your own project to reduce packaging waste? Submit it to the Save the World Wildcard round of the Hackaday Prize which closes on October 16th!

A display in a field showing the water stress index over time

Hackaday Prize 2022: Using Infrared Thermometers To Measure Crops’ Water Stress

September 11, 2022 by 6 Comments

If you live anywhere on the Northern Hemisphere, you’re likely to have experienced one of the many heatwaves that occurred this summer. Extreme heat is dangerous for humans and animals, but plants, including important crops, also suffer. High temperatures lead to increased transpiration and evaporation, and if the water lost in this way is not replenished quickly enough, plants will stop growing and eventually wither and die.

In order to keep track of the amount of water available to crops, [Florian Ellsäßer] built the Crop Water Stress Sensor: a device that checks whether plants have enough moisture available to stay healthy. It does this by measuring the temperature of the leaves to calculate evaporation levels. If the leaves are cooler than their surroundings, this means that water is evaporating from them and the plant apparently has enough water available. If the leaves’ temperature is closer to the ambient temperature, then the plant may be running low on water.

[Florian]’s system performs this measurement using an infrared array, which is basically a low-resolution thermal camera that remotely measures the temperature of everything in its field of view. This IR array is pointed at a field, where it will see both leaves and the ground between them. The difference in temperature between these two can then be used to calculate the Crop Water Stress Index (CWSI), a standardized measure of how well-hydrated plants are. The result is shown on a display and also indicated using a convenient red-yellow-green status LED that shows if the crops in question need watering.

The system can be solar powered for completely remote operation, while its data can be read out through a WiFi interface. [Florian] is planning to update the design with a LoRa interface for greater range: the eventual goal is to build a large network of these sensors throughout agricultural areas and use the combined data to raise awareness of water shortages in certain areas. In order to make the sensors easy to build by anyone interested, all design files are available on the project page.

Keeping crops moisturized is one of the key tasks of agriculture, and we’ve seen several projects that aim to optimize and automate it, from a simple-but-effective ESP8266-based moisture sensor to complete hydroponics systems.

Renewable Hydrogen Sucked From Thinish Air

September 11, 2022 by 26 Comments

Stored hydrogen is often touted as the ultimate green energy solution, provided the hydrogen is produced from genuinely green power sources. But there are technical problems to be overcome before your average house will be heated with pumped or tank-stored hydrogen. One problem is that the locations that have lots of scope for renewable energy, don’t always have access to plenty of pure water, and for electrolysis you do need both. A team from Melbourne University have come up with a interesting way to produce hydrogen by electrolysis directly from the air.

Redder areas have more water risk and renewable potential

By utilising a novel electrolysis cell with a hygroscopic electrolyte, the so-called direct air electrolysis (DAE) can operate with humidity as low as 4% relative, so perfectly fine even in the most arid areas, after all there may not be clouds but the air still holds a bit of water. This is particularly relevant to regions of the world, such as deserts, where there is simultaneously a high degree of water risk, and plenty of solar potential. Direct electrolysis of saline extracted at coastal areas is one option, but dealing with the liberated chlorine is a big problem.

The new prototype is very simple in construction, with a sponge of melamine or a sintered glass foam soaked in a compatible electrolyte. Potassium Hydroxide (alkaline) was tried as was Potassium Acetate (base) and Sulphuric Acid, but the latter degraded the host material in a short time. Who would have imagined? Anyway, with electrolysis cell design, a key problem is ensuring the separate gasses stay separate, and in this case, are also separate from the air. This was neatly ensured by arranging the electrolyte sponge fully covered both electrodes, so as the hygroscopic material extracted water from the air, the micro-channels in the structure filled up with liquid, with it touching both ends of the cell, forming the circuit and allowing the electrolysis to proceed.

Hydrogen, being very light, would rise upward through holes in the cathode, to be collected and stored. Oxygen simply passed back into the air, after passing though the liquid reservoir at the base. Super simple, and from reading the paper, quite effective too.

You can kind of imagine a future built around this now, where you’re driving your hydrogen fuel cell powered dune buggy around the Sahara one weekend, and you stop at a solar-powered hydrogen fuel station for a top up and a pasty. Ok, possibly not that last bit.

The promised hydrogen economy may be inching closer. We covered using aluminium nanoparticles to rip hydrogen out of water. But once you have the gas, you need to store and handle it. Toyota might have a plan for that. Then perhaps handling gas directly at all isn’t a great idea, and maybe the future is paste?

Thanks to [MmmDee] for the tip!