green hacks

824 Articles

Electric Vehicles Continue The Same Wasteful Mistakes That Limit Longevity

May 15, 2020 by 372 Comments

A while back, I sat in the newish electric car that was the pride and joy of a friend of mine, and had what was at the time an odd experience. Instead of getting in, turning the key, and driving off, the car instead had to boot up.

The feeling was of a piece of software rather than a piece of hardware, and there was a tangible wait before the start button could be pressed. It was a miracle of technology that could travel smoothly and quietly for all but the longest journeys I could possibly throw at it on relative pennies-worth of electricity, but I hated it. As a technologist and car enthusiast, I should be all over these types of motor vehicles. I live for new technology and I lust after its latest incarnations in many fields including automobiles.

I want my next car to have an electric motor, I want it to push the boundaries of what is capable with a battery and I want it to be an automotive tour de force. The switch to electric cars represents an opportunity like no other to deliver a new type of car that doesn’t carry the baggage of what has gone before, but in that car I saw a future in which they were going badly astray.

I don’t want my next vehicle to be a car like my friend’s one, and to understand why that is the case it’s worth going back a few decades to the cars my parents drove back when when jumpers were goalposts, and the home computer was just a gleam in the eye of a few long-haired outsiders in California.

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Turn Folds Into Flowers, But Not With Origami

May 5, 2020 by 13 Comments

It is said that you’re not a sysadmin if you haven’t warmed up a sandwich on server. OK, it’s not widely said; we made it up, and only said it once, coincidentally enough after heating up a sandwich on a server. But we stand by the central thesis: never let a good source of excess thermal energy go to waste.

[Joseph Marlin] is in the same camp, but it’s not lunch that he’s warming up. Instead, he’s using the heat generated by his Folding@Home rig to sprout seeds for beautiful tropical flowers. A native of South Africa Strelitzia reginae, better known as the striking blue and orange Bird of Paradise flower, prefers a temperature of at least 80° F (27° C) for the two months its seeds take to sprout. With all the extra CPU cycles on a spare laptop churning out warm air, [Joseph] rigged an incubator of sorts from a cardboard box. A 3D-printed scoop snaps over the fan output on the laptop and funnels warm air into the grow chamber. This keeps the interior temperature about 15 degrees above ambient, which should be good enough for the seeds to sprout. He says that elaborations for future versions could include an Arduino and a servo-controlled shutter to regulate the temperature, which seems like a good idea.

The Bird of Paradise is a spectacular flower, but if growing beautiful things isn’t your style, such a rig could easily sprout tomatoes or peppers or get onions off to a good start. No matter what you grow, you’ll need to basics of spinning up a Folding@Home rig, which is something we can help with, of course.

Giving Surfaces Their Own Antiviral Coating To Fight Infection

April 30, 2020 by 15 Comments

The use of disinfectants is not a new thing, but a major disadvantage with most common disinfectants is that they are only effective in the short term. After applying bleach, alcohol or other disinfectant to the surface, the disinfectant’s effect quickly fades as the liquid evaporates. Ideally the disinfectant would remain on the surface, ready to disinfect when needed.

According to researchers at the Hong Kong University of Science and Technology (HKUST), the solution may lie in a heat-sensitive coating that releases disinfectant when it’s needed. This Multilevel Antimicrobial Polymer (MAP-1) can remain effective for as long as 90 days, depending on how often the surface is touched or otherwise used.

MAP-1 consists out of polymer strands of a material that prevents viruses and bacteria from attaching to its surface, while disrupting its outside surface. Effectively this has the potential to inactivate (kill) most viruses and harmful bacteria that come into contact with it.

MAP-1 is currently being deployed in Hong Kong, where public places such as schools, malls and sport facilities have had the coating applied. It costs between US $2,600 and US $50,000 to treat an area, which is not cheap, but would be cheaper than shutting down such a facility for regular surface disinfecting.

Although it still has to be determined that MAP-1 is as effective as hoped, it is another example of an antimicrobial surface, a material that is designed to be as incompatible with sustaining viruses and bacteria as possible. In the past copper and its alloys have been commonly used for this purpose, but a polymer coating is obviously more versatile. From the point of view of today’s pandemic, making surfaces incapable of hosting viruses definitely can be regarded as highly necessary.

(Pictured: a MAP-1 coating on a surface, courtesy of HKUST)

Coffee Maker Gives Plants An Automatic Drip

April 23, 2020 by 36 Comments

Somehow, [Jeremy S   Cook]’s wife was able to keep a Keurig machine going for 10 years before it quit slinging caffeine. [Jeremy] got it going again, but decided to buy a new one when he saw how it was inside from a decade of water deposits.

But why throw the machine out like spent coffee grinds? Since the pump is still good, he decided to turn it into an automatic plant watering machine. Now the Keurig pumps water using a Raspberry Pi Zero W and a transistor. [Jeremy] can set up watering cron jobs with PuTTY, or push water on demand during dry spells. We love that he wired up a soil moisture sensor to the red/blue LEDs around the brew button — red means the plant is thirsty, purple means water is flowing, and no light means the plant is quenched and happy.

This project is wide open, but cracking into the Keurig is up to you. Fortunately, that part of the build made it into the video, which is firmly planted after the break.

Old coffee makers really do seem suited to taking up plant care in retirement. Here’s a smart garden made from an espresso machine.

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An Arduino-Free Automatic Alcohol Administrator

April 5, 2020 by 30 Comments

With all the hands-free dispenser designs cropping up out there, the maker world could potentially be headed for an Arduino shortage. We say that in jest, but it’s far too easy to use an Arduino to prototype a design and then just leave it there doing all the work, even if you know going in that it’s overkill.

[ASCAS] took up the challenge and built a cheap and simple dispenser that relies on recycled parts and essential electronics. It uses an IR proximity sensor module to detect dirty digits, and a small submersible pump to push isopropyl alcohol, sanitizer, or soap up to your hovering hand. The power comes from a sacrificial USB cable and is switched through a transistor, so it could be plugged into the wall or a portable power pack.

We admire the amount of reuse in this project, especially the nozzle-narrowing ballpoint pen piece. Be sure to check out the build video after the break.

Hopefully, you’re all still washing your hands for the prescribed 20 seconds. If you’re starting to slip, why not build a digital hourglass and watch the pixels disappear?

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Wheelbarrow Bass Drives A Sound Garden

April 2, 2020 by 11 Comments

One of the best things about making music is that it’s so easy to do. There are countless ways to make interesting sounds out of nearly anything if you’re willing to experiment a little bit — just ask anyone who has ever made a guitar out of a cigar box and a broom handle.

[Vicious Squid] dug in to the fertile soil of the garden implement world and cultivated a three-string upright bass with a rich, soulful sound from a familiar workhorse — an aluminium wheelbarrow. Much of the build is made from reclaimed wood, like the solid mahogany neck from an old door frame, and a broom handle.

The bass is constructed arch-top style, meaning that the soundboard — the wood on the front with the f-holes — is a flat piece tacked to curved ribs that span the width of the ‘barrow. A broom handle sound post mounted front to back pushes vibrations from the soundboard to the aluminium body. To round out the agricultural aesthetic, [Vicious Squid] strung it with weed-whacker bass strings, which are no doubt inspired by the use of actual trimmer line.

It’s already plenty loud, but [Vicious Squid] added a piezo pickup for wheeling it into the recording studio. Slap your way past the break to hear a little ditty.

Are your instrument-building skills at the sapling stage? Start with something simpler, like a sliding rubber bandolin.

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Microbatteries On The Grid

March 27, 2020 by 35 Comments

Not everybody has $6500 to toss into a Tesla Powerwall (and that’s a low estimate), but if you want the benefits of battery storage for your house, [Matt]’s modular “microbattery” storage system might be right up your alley. With a build-as-you-go model, virtually any battery can be placed on the grid in order to start storing power from a small solar installation or other power source.

The system works how any other battery installation would work. When demand is high, a series of microinverters turn on and deliver power to the grid. When demand is low, the batteries get charged. The major difference between this setup and a consumer-grade system is that this system is highly modular and each module is networked together to improve the efficiency of the overall system. Its all tied together with a Raspberry Pi that manages the entire setup.

While all of the software is available to set this up, it should go without saying that working with mains power is dangerous, besides the fact that you’ll need inverters capable of matching phase angle with the grid, a meter that handles reverse power flow, a power company that is willing to take the power, and a number of building code statutes to appease. If you don’t have all that together, you might want to go off-grid instead.