The Metabolizer

A living recycling center that eats trash and sunshine
and poops recycled plastic objects

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"The Metabolizer" is a proof-of-concept prototype for an open-source, off-grid, small-scale waste processing system that can be powered entirely by trash and sunshine.

Back in early 2018, I submitted this wacky idea to the Hackaday Prize, and was selected as a finalist and awarded $1000 to keep hacking. I spent the whole summer and all of the money working it, and made some intriguing progress, but failed to produce a working prototype, and didn't make it to the finals.

After that, I moved my updates to over Patreon, which gave me a small budget to keep hacking at it, and now, 3 years later, I've finally built a working prototype - I can now 3D print plastic objects directly from recycled plastic flakes, using solar power and waste biomass! Hopefully, so can you!

In keeping with this year's theme to reinvent, reimagine, and redefine, I've re-built this page with everything that I've learned since 2019!

Problem Statement

The Metabolizer is sort of like an ecological Rube Goldberg machine- it's a chain reaction-type system intentionally designed to perform a simple task in an overly complicated way.

In this case, the simple task is "not throwing our plastic trash in the ocean", and the overly complicated way of doing it is "by designing an artificial metabolic system that can literally eat trash."

Like a Rube Goldberg machine, a big part of the challenge of this project is to see how long you can keep the chain-reaction going for. Unlike a Rube Goldberg machine, the chain reaction is fundamentally reciprocal and solar powered and can generate energy while breaking down and wastes and recycling plastics, for as long as there is trash and sunlight around for it to eat.

How long could a system like that realistically sustain itself? Hours? Days? Months? Years? Centuries? Forever? At what point would you start to consider it to be a single living organism, not just a collection of independent parts?

I don't know the answer to those questions, but those are the questions that motivated me to build this project. The central challenge of the Hackaday Prize is "build the best hardware module or device possible for the boldest solution you can envision." This is the boldest solution I can envision.

Going Live

Here's how it currently works: When sunlight hits the solar panels, it charges up the battery bank inside of the Powerplant, providing the base power that starts the reaction. When the battery fills up, solar power is dumped into a heating element inside of the Biochar Reactor, causing the biomass inside to heat up and reducing it to biochar, generating a thick smoke that is cooled, collected, and refined, before it is pumped into the air intake of a small gasoline generator, which generates 200-900W of DC power, which feeds back to the Power Plant, and is converted into 120V AC which powers the 3/4hp motor attached to the Waste Shredder, which grinds up waste plastic trash into flakes, which are fed into the hopper of the Trash Printer, which extrudes the plastic into light, strong 3D printed objects.

Sorry for the run-on sentence there, complex systems are really hard to describe.

The system operates entirely off the grid, which means that if the battery dies, the whole system dies. The chain reaction stops. The lights go out, your phone stops charging, the counter resets. You have to wait until the sun comes out and try again. It's kinda like a giant trash-eating Tomagachi.

The challenge that fascinates me, and that I hope will be interesting to y'all as well, is to see how long I can keep this system alive, and keep score of how many useful resources I can generate in the process - how many kilowatt hours of sunshine energy I can sink through the system, how many kilograms of carbon I can sink into the soil, how many kilograms of plastic I can forge into something useful.

With the current prototype, what I'm calling my Latest Stable Release, my high score is about 4.5 hours. But in that time, was able to turn a handful of old take-out containers into a 3D printed cup, and I generated about 450 watt-hours of energy from trash, and a not-zero amount of biochar, using ONLY a days worth of sun-shine, amazon packaging, and woodchips as the fuel (3.8kWh). I even mixed some the powdered char dust into the trash printer which turned the prints a very nice shade of black.

Not too bad, for a first run ever, all things considered.

You can watch a highly-abridged timelapse of that first run here:

I've come A LONG way over that past 3 years, and in that time the system has gotten significantly cheaper, efficient, and easier to build. But there's still a long way to go before the system is really useful, let alone disruptively useful. 

This is my call to all the makers, tinkerers, and mad engineers out there who may be reading this- A very wise friend of...

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Seize The Memes Of Production!

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Flake Extruding Print Head SketchUp Model- V1 9-29-18.skp

Most current 3D model of flake extruding head I'm using on the MPCNC. So far, I know it works, in that it extrudes a consistent bead of plastic (currently PP, #5) in response to computer control of the stepper motor. Many improvements can (and will) be made to this design, but it's low cost, easily sourced parts, and good-enough performance warrant documentation. This model is MOSTLY to scale, but not in any technical way, so go by the stated measurements, rather than the model measurements, and make sure to check everything against what you can actually find at your local hardware store.

SSEYO Koan Play File - 4.74 MB - 09/29/2018 at 22:29



All 3D print files for building the MPCNC with exactly 1" (25.4mm) OD stainless steel or aluminum tubing (NOT for conduit)

Zip Archive - 3.98 MB - 09/28/2018 at 18:56


View all 7 files

  • 1 × The Biochar Reactor - $1800-$2000 Check the google drive in the links section for the most-current parts lists and documentation.
  • 1 × The Waste Shredder - $800-$2500 Full plans available on, and as a ZIP file in the files section. Build notes in the Instructions section. Check out the Precious Plastic forums before you build!
  • 1 × The Powerplant - $2000-$5000 Check the google drive in the links section for the most-current parts lists and documentation.
  • 1 × The Trash Printer $650-800 Check the google drive in the links section for the most-current parts lists and documentation.
  • 1 × 24VDC Generator I got the "2500" version, which is yellow.

View all 17 components

  • September 2021: Char-vest Moon

    Sam Smith10/26/2021 at 18:50 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    September 30th, 2021

    Since I first started this project, my goal has been to demonstrate a system that can use sunshine to turn organic wastes into biochar, using the gas generated in the process to generate electricity to power a waste shredder that shreds up waste plastic that is fed into the trash printer, turning sunshine and waste into biochar, energy, and 3D printed plastic objects - a complete metabolic system nourished by trash and sunshine.

    Over the past 5 years, with your support, I've gotten all the pieces of that system working individually, and now it's time to put them all together. 

    This month, that meant putting a lot of things BACK together. Last month, I had fully disassembled the biochar reactor in order to try out a new design I've been working on, one that I hoped would make it easier to build, more efficient, and easier to operate. The first test, however, did NOT go so well. My thinking went like this:

    If I insulate a 5-gallon metal bucket, and I put the heating element inside that bucket, maybe I can nest another 5-gallon bucket full of biomass fuel inside it, and that would make it possible to load and unload batches of biomass like fuel cartridges, 5 gallons at a time. It would make the whole systems SO much easier to use, instead of having to scoop out the charcoal every time.

    In order to distribute the heat, I filled the bottom of the bucket with Zeolite pellets, a type of dessicant make from alumino-silicate clay. My thought was that the zeolite would get hot and transfer the heat of the burner to the nearby metal.

    Unfortunately, that's not what happened. What actually happened is that I accidentally made lava. It turns out the zeolite is INCREDIBLY INSULATING, which seems obvious in retrospect, and it built up so much heat that it melted the zeolite into glass, and melted the nearby aluminum foil, which shorted out the heating element.

    BAM. Lava. The good news is that all that really happened was I burned out my heating element, and got more than a little discouraged. But I used my Patreon budget to buy a new heating element and try again. This time, no zeolite. 

    And this time it worked! Better than before, more efficient, easier to load and unload, and easier to measure the inputs and outputs. I ran a test using raw, VERY wet douglas fir chips, to see how well the system dealt with that level of moisture.

    It turned out to take a lot more energy than usual, 8.1kWh in total, and it only pyrolized half the batch. In the process, it generated around 1 cubic meter of syngas, which I used to power the generator for about an hour in total, generating 250 watt-hours of power, a new record! It's not much, but even with extremely wet material I was still able to get an energy in to energy out efficiency of nearly 3%, which is also a new record for me.

    I've begun putting together the final 3D model for how all the parts go together, which will become the basis of the documentation for how to build one. I'm hoping to make the initial release of the reactor documentation by the end of the year.

    Now that the reactor is working, one of the final pieces is to get the trash printer running on the power produced by the generator. So I spent the last part of this month rebuilding the trash printer, which has been out of commission and in storage since the beginning of the pandemic. 

    The wiring was a mess, and the table I was using was too big. So I had to take it all apart, transfer it to a smaller table, replace the Z motors, and mess with it for hours, but I finally got it printing again.

    The Trash Printer, it turns out, when printing, takes about 160 watts. With the 250 watt-hours I generated, I could print a cup,...

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  • August 2021 - Reactor Upgrade!

    Sam Smith10/26/2021 at 03:24 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    August 31st, 2021

    This month I spent some time making some final tweaks to the design of the reactor. I've tried a bunch of different configurations at this point, and in general the design works quite well, and it can reliably produce gas clean enough to generate energy with. 

    But I wanted to make a few changes based on what I've learned so far to make it a little more modular, more efficient, a little easier to use, and cheaper to build.

    I've revised my parts list for this new configuration, which you can find here. Keep in mind that this is still a draft, but it's getting very close to being a stable build. 

    First, I've learned that firing a whole batch of charcoal currently takes between 5-8 hours, which is a pretty long time. I decided to test out a configuration where I added extra insulation, and used steel 5 gallon buckets packed inside the reactor.

    This change will let me pack burnable material into 5-gallon buckets, and load them into the reactor like fuel cartridges, which I hope will make the whole process of operating the reactor a lot quicker and easier. It reduces the volume of char you can make with each batch a bit, but it should also reduced the time it takes to cook a batch to around 3-4 hours.

    I also bought a set of 1.5" condenser tubes to try out instead instead of the 2" ones I'm currently using, because they're a lot cheaper and if they work just as well, then it will make the whole reactor design a lot lighter and cheaper by using 1.5" fittings instead of 2".

    I also figured out how to configure the condenser parts in a way that is a lot stronger than my original design, which allows the reactor to be oriented horizontally as well as vertically, and is just generally a lot sturdier and easier to move around. It makes it feel like a lot more of a thing instead of a collection of parts.

    Unfortunately, whenever I pull the reactor apart to make upgrades like this, it puts it out of commission for a while, and so I haven't been able to make much charcoal recently, or play with fire very much.

    My goal for this coming month is to get this new configuration up and running and do some tests, and based on what works and what doesn't, start building the documentation for the first stable release of the reactor.

    Thank you all so much for your support! Stay tuned!

  • July 2021: Pump up the volume

    Sam Smith10/26/2021 at 03:21 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    July 31st, 2021

    For months, I've been on a quest for cold hard data. What I ended up with this month was more like soft, warm data, but hey, you've gotta start somewhere. For the first time ever, I was able to measure all the inputs and outputs of my biochar reactor to make one batch of biochar. Here are the quick results:


    Biomass in: 3.3kg

    Moisture Content: Unknown, dry

    Electrical Energy Consumed: 8.7kWh


    Charcoal Out: 1.8kg

    Liquid out: 550mL

    Electrical Energy Generated: 140wH.

    Syngas Produced: 1400L

    The feedstock was just the woody remnants of last year's yard-work: Dried out hops, wisteria, and clematis vines, blackberry brambles, weeds, grass, and sunflower stalks. I've gotten into the habit of just drying out my yard waste by leaving it in a big bin in front of my house's heat pumps, using the waste heat to dry it all out, and then throwing it into the biochar reactor.

    I have always been curious exactly how much biomass energy is available just from the stuff that grows on my 1/10th acre lot in Portland, because it seems like kind of a lot. I still don't know exactly, but I'm getting a lot closer to knowing. 

    I weighed the bucket empty to establish a tare weight, then used a luggage scale to measure how much biomass I had. By compacting this dry, low-grade  woody biomass waste into a 7-gallon turkey fryer bucket, I was able to collect about 3.3 kilograms of biomass. Then I loaded it all into the reactor, sealed it up, and heated up the heating element, using 1128 Watts total. 

    In about 45 minutes, I had filled a 300L gas bag with gas,

    Over the course of the afternoon, the bag filled up with 300L of gas roughly every hour, and every time it filled up, ran the generator for 7-9 minutes, producing between 250-400W on average from roughly 300L of gas. Later, I tried using a larger, 500L bag, and found that I could run the generator for nearly 30 minutes on one 500L bag.

    When I turned the reactor off that evening, the temperature read 850F, and 8.71kWh had been consumed. That means that the system consumed 8710 watt-hours, and generated 140 watt-hours, roughly a 1.3% conversion. Not great.

    But not bad either, considering its my first try and the purpose of this project isn't ONLY to produce energy. 8.7kWh is an amount of power easily generated by 3-6 solar panels over the course of a sunny day, and the byproducts of the process also include waste processing, biochar production, water heating, and gas production, in addition to electrical power. So 1.3% as a first try ain't too bad.

    Most of the time, when the generator was running, it was producing between 250W and 400W - about as much as a single solar panel does in full sun. On gasoline, the thing is supposed to generate up to 1800W. But the energy-content of the syngas varies depending on the feedstock, temperature, and a number of other factors.

    The low conversion efficiency is most likely due to the air-fuel mixture inside the generator. Getting the pressure and gas volume just right has been a tricky business. The new gas bags I got are cheap and very easy to work with, but they require some kind of pump to pressurize the gas. The booster pump I was using worked pretty well, but topped out at around 400W.

    Unfortunately, the gas booster pump I had been using ended up getting clogged with tar and stopped working. Ultimately, that's a filtration issue, indicating that the gas needs to be cooled and scrubbed more before it gets stored. I've ordered a few filters to try, and a few new pumps.

    When I bypassed the pump, however, and just leaned my weight onto the bag to provide pressure (later calculated to be roughly 15psi) the generator fired right up, and I was...

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  • June 2021 - It's a new record

    Sam Smith10/26/2021 at 03:19 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    June 30th, 2021

    Hello Dear Patrons, and welcome to another monthly update.

    It was 116 degrees in Portland this weekend, a new record for as long as we've been keeping score. I feel like I've been preparing for this kind of thing to happen my entire life, but it still comes as quite a shock when it does actually happen.

    I don't know really know what to say or make of it just yet, but I invite you to let yourself feel the reality of it sink into your bones for a moment, while that feeling of 'way too hot' is still fresh.

    For the rest of all of our lives, no matter what any of us do, the weather will become increasingly inhospitable. There will be heatwaves, cold-snaps, hurricanes, droughts, wildfires, and floods.  But that doesn't mean that what we do now doesn't matter. It means that what we do now matters a lot.

    But what, exactly, do we do? I can't tell you what the right thing for you to do is, but I can tell you that I have asked myself this question many times, and the conclusion that I've come to is this:

    Everyone has a different opinion about how they think the world should be, and we don't have time for everyone to agreed about it, nor is that likely to happen, ever. But there are certain things that all humans will always need, and so it makes sense to just focus our energy there first.

    Food, water, shelter, energy, waste. No matter what happens, come hell or high water, any information that helps people meet the basic needs of the people around them, using the things they have around them, will always be useful information.

    I called this page "disruptively useful" not because I think the stuff I'm working on is currently disruptive, but because I am convinced that there is such a thing as disruptively useful information - information that is so useful that it can actually change the way people do things, simply by being available to them.

    If you and your friends can build something useful that helps you take care of each other, and you share that information so that other people can build that thing too, then that information can spread around the world faster than it ever has before. The potential and need for us to change how we do everything has never been greater.

    So if we're going down, let's go down swinging for the fences. If we're shattering world records for temperature, let's shatter world records for how much carbon we can sink into the soil, how much plastic we can pull from the oceans, how many people we can care for the people around us using nothing but wind, rain, trash, and sunshine.

    This month, on the hottest day of the Holocene, after the sun finally set, I set two small personal records. I ran my generator for 26 minutes, unassisted, on the stored biomass-gas alone, for the first time. I also learned how to auto-start the generator with just one button for the first time.

    Not a world record by any means, but a personal best.

    This coming month, my goal is to finally be able to measure ALL of the inputs and outputs of the biochar reactor. These numbers will mark a milestone that I've been working towards for a long time - the ability to quantify exactly how much carbon this system can pull out of the air, how much trash it can decompose in the process, and how much solar power it can convert into useful energy.

    Those numbers probably won't be great, or at least, they will probably need to be greatly improved before they become disruptively useful. But to know for sure, I need to find out what those numbers are, so that I can set new records, and break them, and invite other people to break them, over and over again, until we're setting world records, and breaking them, over and over again.

    Thank you for all your support,...

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  • May 2021 - In the bag

    Sam Smith10/26/2021 at 03:15 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    May 31st, 2021

    Hello dear Patrons! 

    This has been an exciting month! At the end of last month, I finally got the generator running reliably on biomass gas, and was able to generate 250-350 watts at idle, with a peak of 700-800 watts when I put the gas under higher pressure. This month, I was able to run a few more experiments, and was finally able to run the generator continuously for over 20 minutes until I turned it off.

    This generator produces 24 volts DC instead of 120 volts AC like most generators, which means it integrates really easily with existing systems already designed for solar panels. Here I've got the generator charging up my 2.4kWh lithium battery bank, and I can use that battery bank to power the reactor (700W), or the shredder (600W) or the trash printer (200W).

    The limiting factor now is my ability to store the gas that the reactor produces. I can only store about 40L of gas in my gasometer, which can run the generator for about 5 minutes. So I started experimenting with pumping air into the reactor once it was started, in order to generate additional heat and gas, like stoking a fire by blowing on the hot coals. 

    I got this special remote control valve so that I could pump air into the reactor without letting the gas escape when the pump wasn't running. This way, I can give the pump and valve 12 volts and the pump will start and the valve will open, and then when I turn off the power, the pump turns off and the valve closes.  

    I was able to run the generator for about 20 minutes that way. I also tried recirculating the exhaust from the generator, and that worked surprisingly well, but not great. 

    The problem is that doing that dilutes the gas with nitrogen and CO2, which makes the gas less calorific, and throws off the air-fuel mixture in the generator, leading to less power, and less reliable starting. The gas remains flammable and can still be burned in the flame tube, but it doesn't have the energy density the generator needs to really get going.

    So, with your support from last month, I ordered this giant gas bag, designed for storing biogas, which just arrived today. These bags are cheaper to buy and easier to use than the gasometer I have been using, and don't require any water to work, which makes them a considerably lighter and more portable option. 

    This bag is 0.5 cubic meters, or 500L, or roughly 130 gallons. That should be able to hold roughly 5000 watt-hours of chemical energy, which the generator should be able to convert into roughly 500-600 watt-hours of electrical power.

    This coming month, I plan to use my Patreon budget to buy a decent battery monitor and a 24V battery bank, so that I can more accurately measure the energy consumed and produced by the system, and start running the system completely off the grid, using exclusively solar power and power produced from biomass.

    Stay tuned!

  • April 2021 - Positive Feedback

    Sam Smith10/26/2021 at 03:13 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    April 30th, 2021

    Hello Dear Patrons, and welcome to everyone who signed up on or around my birthday! I gained over $20 patrons, bringing my hacking budget up to over $650/mo, a new record! 

    Waaaaay back in October, I spent weeks putting together the best proposal I possibly could for the LAGI2020 initiative, a design competition for regenerative structures to be build and tested on the Fly Ranch property in Nevada, now owned by the Burning Man org.

    I tried to sum up as succinctly as I could, exactly what it is that would like to build: a fully open-source closed-loop basecamp that can be rapidly deployed and power itself entirely on trash an sunshine, able to meet 100% of the primary human needs of a small group of roughly 30 people, by metabolizing locally available waste biomass and solar power into useable energy for essential needs like lighting, heating, cooling, cooking, washing, bathing, and building.

    But I've been sworn to secrecy until after the shortlist of winners had been selected, which just happened this month. My proposal didn't make it on the shortlist, which is a disappointment and a relief, and it is now published on LAGIs website, so you can go explore it there, and while you're there, check out the ones that did get shortlisted, they are DOPE.

    Now that the results are published, I can FINALLY share all that work I did with all of you without fear of disqualification. So I would love if you would explore it in detail and see what comes across for you. These are the three design boards I submitted as my proposal.

    The thing that I find so intriguing about metabolic systems, like organisms and ecosystems, is that they're an ongoing process, a constant balancing act, something that is always happening. As Buckminster Fuller put it, "I seem to be a verb."

    All living organisms, by definition, have a metabolism. But do cities? What about cars? What about rainforests? Whats the difference between them? A metabolic system is any set of chemical processes that is able to sustain itself through time, to grow, replicate, and adapt as needed to keep that process going. 

    This camp is research center for an experimental metabolic system, that is arguably alive, at least metabolically speaking. If you don't feed the system, you run out of power, the system reboots, the counter resets, and you have to start all over. The camp itself is a challenge, a platform, a feedback loop that lets people experience what its like to live within a living system, and work to maintain the systems that sustain them.

    It would be a platform that small crew of people would have to work together to operate, requiring communication and trust, just like the crew of a ship (or starship).

    If a bunch of groups started doing that, and competing with each other to see how long they can keep their system going, and sharing their mods and hacks with each other, so that other groups can replicate the designs that work well, with only open-source tools and locally available materials. If even a few groups of people started doing that, I bet we could get pretty good at it pretty fast!

    All of the infrastructure proposed in this design already exists, fits inside a shipping container, and costs between $10,000 and 20,000 in parts. That's a lot of money for one person, but not very much for 15-30 people, especially if those people can then set up that camp infrastructure anywhere and have it meet all of their essential needs.

    Phew. So, yeah. That's what I'm trying to do, as specifically as I've ever been able to put it. Thank you for all your support, it's made doing so much of this work possible.

    So now lets shift gears to the brass tacks of how do you actually do that....

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  • March 2021 - Solar Power to the People

    Sam Smith10/26/2021 at 03:11 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    March 30th, 2021-

    Happy Spring, dear Patrons!

    This past month I’ve been grinding away at this enormous project by focusing a lot on power. I started this month by experimenting what I could do with the trash-gas produced in the process of making biochar, besides turning it into electricity. The generator I ordered is still in transit (stuck in the Suez Canal, maybe?) so I’ve been trying to turn my attention to other useful things.

    One experiment I did was to see if I could create artificial lighting from the gas, without electricity. I used Coleman gas mantles, and they actually worked pretty well. This is how street lights used to work before the advent of electric lighting.

    Next, I tried boiling some water to make some go old fashioned tea. I tried to calculate how long it took boil, so that I could calculate the energy usage. It was a little complicated though, since I had to accumulate the gas and store it in batches, which made it tricky to meaningfully calculate the energy return. Still, I did manage to boil enough water for a few cups of tea, and that’s pretty neat.

    And then of course, there’s the option of just flaring the gas, which still looks awesome.

    But the ultimate goal of this project is to create a set of machines that can generate useable power from waste, and so an electrical storage system of some kind is going to be a necessary part of that system.

    And so I’ve fully redesigned our power system in the Magic Tool Bus, as a te,st of the off-grid energy storage system that I want to design to capture and store the power produced by the generator. These are all components I’ve been selling at Light Harvest Solar for almost a year now, so its really fun to get to use them myself.

    You can check out my preliminary documentation on that part of the project on my google drive!

    That’s all for now, stay tuned for next month, hopefully I’ll be able to get this little generator I ordered running on trash gas and charging up this system as an alternative to solar!

  • February 2021 Project Update

    Sam Smith10/26/2021 at 03:08 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    February 28th, 2021-

    Happy almost-Springtime, dear patrons.

    This month's budget went towards the LEDs that we put onto the LOVE trikes for Portland Winter Light Festival! The first weekend of the festival was a wild success, and the second weekend of the festival was wild blizzard that forced us to cancel both of our rides. Still, we got some great photos from the first weekend.

    This entire display only takes 40-60 watts- less energy than a single incandescent light bulb does!

    We even made it into the Williamette Week's spread about the Winter Light Festival, and the LOVE tikes were in 5 out of the 10 photos.

    Now that we know that they work, the next step is get them all running on solar power, and then carting around even more deployable infrastructure.

    Thank you for your patronage!

  • January 2021 - What LOVE looks like in public

    Sam Smith10/26/2021 at 03:06 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    January 30th, 2021-

    Hello dear patrons, and welcome to another monthly project update!

    I've made some exciting progress this month on the Biochar Reactor and the LOVE trikes, and have added some new designs for an off grid power storage system to the Power Plant section of the Don't Panic google drive where I'm keeping all my documentation.

    Over the past few months, a group of friends and I, collectively referred to as the Future Problems Collective, have been revamping the LOVE trikes with addressable LEDs and mobile infrastructure as a mobile pop-up art installation for Portland Winter Light Festival! We'll be riding the trikes around Portland, visiting the various distributed art installations around the city and generally being nice to people! You can find our routes on this map.

    If you are in Portland and would like to join our ride, meet at the Northwest corner of Irving Park, BY 6pm, every night of the event - Feb 5 and 6th, and Feb 12 and13th.

    I've also made some exciting improvements to the Biochar Reactor! The Tesla Coil-based ignition system is working splendidly, and has so far it has only exploded in exactly the ways it's supposed to. 

    The Tesla Coil provides a constant spark so that as gas begins being produced by the reactor, it ignites and flares as soon as it becomes flammable.

    This means that now I can just turn on the reactor and leave it alone, and it will automatically flare the gas through the tube as the default process, and then if I want to, I can redirect the gas to the generator to produce electricity.

    The flare tube lets the operator visually confirm that the fuel is flammable and clean before using it for more sensitive things like the generator, which is a really handy feature, and looks dope as hell, if I do say so myself.

    I also mounted the reactor on to an 800lb-rated hand truck, so now it's portable! It's not quite ready to carry around with the LOVE trikes and provide mobile heat, light, and power from biomass, but that's the ultimate goal, and it's closer than ever before.

    Speaking of generators, I successfully ran my little generator a few times with this new setup, and I even produced a few watt-seconds of useable power, but the pull-start makes it difficult to automate, and the raw DC output of the generator without the inverter circuit was well over 100 volts, which my charge controller didn't like very much.

    So, because of your generous patronage, I was able to order one of these DC generators from AliExpress, which should arrive in 20-38 days.

    This generator cost around $650 shipped, and it can stop and start itself automatically according the batteries voltage, and/or with a wireless remote. It uses it's generator motor as it's starter motor, exactly like I was trying to do over the summer, but better. 

    If it works, it also means a lot less hacking for people like you who may one day want to replicate this system, since this is a product that already exists and should require only minor modification to get it running on biomass gas, rather that the way I was doing it, which was VERY hacky.

    Since the Tesla Coil and Trash Printer already run on 24VDC, getting the system charging a 24VDC battery bank from biomass gas would be a major step forward towards a fully trash-powered system.

    So I've also begun designing a 24VDC LiFePO4 battery bank, with an inverter and solar charger system, using cells you can get from AliExpress. 

    I've learned a ton about building and designing off grid systems like these by working at Light Harvest Solar, and I think I can build a very powerful 24VDC system, with the ability to start and stop the generator according to pre-set parameters. 

    This part of...

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  • December 2020 - DON'T PANIC: 2020 is hindsight.

    Sam Smith10/26/2021 at 03:03 0 comments

    [UPDATE 10/21/2021 -After 2018 I started posting my updates on my Patreon page, and so I'm filling in the back-logs for this project retroactively so the whole story is in both places. You can also read all of these posts with their original photo formatting here]

    December 31st, 2020 -

    “In many of the more relaxed civilizations on the Outer Eastern Rim of the Galaxy, the Hitch-Hiker's Guide has already supplanted the great Encyclopaedia Galactica as the standard repository of all knowledge and wisdom, for though it has many omissions and contains much that is apocryphal, or at least wildly inaccurate, it scores over the older, more pedestrian work in two important respects. First, it is slightly cheaper; and secondly it has the words DON'T PANIC inscribed in large friendly letters on its cover.”

    Happy New Year, dear patrons! What a fucking year it's been. Fuck. First off, if you happen to be reading this on New Years Eve and have nothing to do tonight, I'll be streaming Overview, the hour-long history of the universe dance party experience that I've been working on for years, live on Twitch, every hour, on the hour, until 2021 or until they shut me down for copyright infringement, whichever comes first.

    Speaking of copyright infringement, isn't the concept intellectual property lame? Wow. Just, wow. But, if I've learned anything from building open source infrastructure, is how easy it is to forget to actually open up your source.

    Source code can be vulnerable, for me at least. It's disorganized and buggy. It's full of mistakes that parts of me don't want other people to see. And it takes a lot of work to write it all down. And besides, why would I take the time to document this version, when the NEXT version is going to be so much better? 

    After all, why shouldn't I keep it?

    The truth is, not sharing information is easier than sharing it, and thats a big part of the problem when it comes to open-sourcing everything. 

    So this year, my resolution is to just start keeping an openly accessible public drive, with all of the documentation and useful information that I have accumulated, and using that as my live lab notebook, including the current models and design files I have, and the best documentation I have, as I make it. 

    If you're reading this, you can see and contribute to this documentation folder, which is currently available as a Google Drive folder entitled DON'T PANIC

    It's an open book, a living document that I will add to and update as my projects evolve, rather than waiting to publish perfect documentation for the perfect version of the thing. If I have it, you have it.

    I'll just post whatever I have there for now, and you can do whatever you want with it. Currently it includes a draft of steps to build the Biochar reactor, and a draft of a parts list with links to where you can source the parts, and a few other useful resources. I'll be adding to this drive consistently in 2021, and everyone reading this has comment privileges with THIS LINK.

    It is the beginning of what I hope will be just my small contribution to the real hitchikers guide to the galaxy, the sum total of know-how needed for anyone anywhere and anywhen to survive in this universe, an open-source guide for exactly how to build all of the tools we can think of that enable all people to always meet all of their needs and care for the people around them using only the abundant flux of solar energy that courses through the atmosphere and into our veins, pumping iron through our hearts and bursting out of us in a pulsing magnetic flux the same shape as the four generations of stars that died to make us us, and though it has many omissions and contains much that is apocryphal, or at least wildly inaccurate, it scores over the older, more pedestrian work in two important respects. First, it is slightly cheaper; and secondly it has the words DON'T PANIC inscribed in large friendly letters on its cover.


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  • 1
    Building the Biochar Reactor

    The current version of the Metabolizer uses a stainless steel whiskey still from AliExpress as it's Biochar Reactor. This whiskey still is more expensive than the kegs that I originally used, but it is A LOT easier to build, and requires no metal fabrication, cutting, or welding to build. In fact, the whole thing can be assembled with basic hand tools in a couple hours.

    You can find the most up-to-date Parts List Here. All told, the parts costs around $1500-2000 shipped. The Latest Stable Release used 2" Tri-Clamp fittings for the condenser, but now I'm testing out a new version that uses 1.5" fittings because they're considerably lighter, cheaper, and smaller, and still seem to work as well. You can find the parts list for that experimental configuration Here.

    The full build documentation is still a work in progress, but is available here. Be sure to read the precautions section and understand the risks of operating a system like this before you build it. Working with heat, electricity, and flammable gas carries inherent risks, and if you choose to build this reactor, you must understand those risks so you can take proper precautions.

    The reactor has 3 main parts: The Reactor, the Condenser, and the Gas Storage Bag.

    The Reactor

    The reactor is a steam-jacketed whiskey still from AliExpress, made by a company called Distillex. I chose it because it's something people can just buy, and not have to fabricate stainless steel, which is a high bar. The still has all the ports and fittings I need to add temp sensors and condensers, and the double-wall steam jacket helps insulate the reaction, and allows me to recirculate hot exhaust from the generator to help add heat. A non-steam jacketed version would be a lot cheaper, but I haven't tried it yet. The reactor should cost under $1000 shipped.

    The Condenser:

    Connected to the Reactor is a water-cooled condenser, made of Tri-Clamp fittings. These fittings are like legos, and you can configure them together in infinite ways. All the condenser does is cool the smoke that comes out of the reactor, and collects the liquids that condense out of the gas in the process. Cooling the gas selects for the lightest hydrocarbons, and refines it into a clean flammable gas, producing hot water as a by-product.

    The Gas Bag

    In my first tests, I used a "gasometer" to store the gas.  A gasometer is simply a barrel floating upside down in another barrel full of water. The inner barrel rises as it fills with gas, providing both storage and pressure. Gasometers are fascinating devices that have been used for hundreds of years. But they are also somewhat tricky to build, VERY heavy, and can only store a limited amount of gas - in my case about 40L, which can only run the generator for a few minutes.

    I'm now using a gas storage bag designed for storing Biogas, and these are much cheaper, lighter, easier to work with, and can store a lot more gas. I'm currently using a 300L bag and a 500L bag. A full 500L (1/2m3) bag will run the generator for over half an hour. In the future, I would like to have as much a 5000L (5m3). In my experience, a full batch of biochar will generate between 1-4 m3 of gas, depending on the energy and moisture content of the biomass feedstock.

  • 2
    Building the Trash Printer

    The Trash Printer has two primary parts - the flake extruding print head, and the gantry that moves it around. 

    The Extruder

    The flake extruding print head is fairly easy to build, and costs roughly $150 in parts. You can find the full parts list here, and you can watch this tutorial on how to put it all together:

    The Gantry

    So far, I've tried the MPCNC gantry, and the LowRider2 gantry, both from Both work about the same, but the LowRider2 can do larger parts and is easier to transport. These gantries are both easy to build, and I chose them because they use primarily 3D printed parts, can commonly available hardware. You can find the full documentation on how to build these machines here. Typical cost to build is $500 or less.

    To control the gantry, I'm using a RAMBO 1.4 control board, running Marlin firmware. You will need to flash Marlin on your board, using the Arduino IDE. Instructions for how to do that can be found here.

    The Software

    To control the Trash Printer, I am using Repetier-Host, running on a Windows 8 laptop. Repetier-Host I am still experimenting and dialing the settings, but I have found that a tip and barrel temp of 250C seems to work well.

    Hacking it all together

    There are just a few minor hacks I had to make to get everything working together.

    The barrel heater on the extruder is designed for 120VAC, but the Rambo Board runs at 24V DC. To bridge this gap, I added a Solid State Relay, that is triggered when the DC "heated bed" output is on. This in turn switches 120VAC on and off, and turns the band heater and and off as needed. Since having an actual heated bed would be impractical for a printer this larger, I've "tricked" the printer into treating the band heater as the "heated bed". This lets me control the tip temperature and bulk barrel temp independently.

  • 3
    Building the Waste Shredder

    The shredder I'm using is a "Precious Plastic" open-source shredder. If you're not aware of the Precious Plastic movement, you should be! It's an open-source effort to develop low-cost, community-scale plastic recycling machines. It's deeply inspring and it's what started me off on this journey.

    I'm using the original shredder box design, which has it's flaws but absolutely works. Precious Plastic has since released an updated heavy duty shredder, which is extremely powerful but more expensive and difficult to build.

    The shredder box cost me about $400 to get the parts cut in stainless steel, and it took a few days to assemble. Overall, the shredder is the most technically difficult component to build, and requires access to a metal shop, ideally with a lathe, MIG welder, and grinder.

    Alternatively, you could just buy a plastic shredder from aliexpress for not much more money. 

    The electric motor and gear reducer was the hardest part for me to source, and cost me another $300. You don't have to use a PP shredder, but they're the best open source option I know of. An industrial shredder might work a bit better if you can find one, but the scale of the Precious Plastic design is ideal for backyard processing. 

    Find full plans at, or in the files section of this page. I highly recommend reading the Precious Plastic forums before building- you'll find a lot of improvements and hacks there.

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Jan wrote 02/05/2019 at 20:39 point

Hey there. Is the project halted? I'd love to see some updates and upgrades :)

  Are you sure? yes | no

Sam Smith wrote 02/05/2019 at 22:13 point

Hey Jan, thanks for the reminder. I took a breather after making a sprint to make the Hackaday Prize deadline, but the project is still very much alive. There is additional info at, if you haven't checked that out yet, although I would like to add more to that as well. The project is in my backyard, not a shop, and so the cold weather has hindered my ability to tinker on the mechanical bits, so I've been focusing on instead on teaching myself how to set up IoT sensors so that I can start getting real numbers on the energy conversion (energy in v energy out). Based on my experience and research, and I am convinced that the process is very energy-positive, but I also understand that most people are rightly skeptical of experimental energy systems until there is hard data behind it, so I'm trying to get that data. I bought some ESP8266 boards and sensors, and so now I'm trying to get some friends who speak robot to help me program them. If you have specific questions about the project, feel free to ask them here and I'll do my best to answer.

  Are you sure? yes | no

Tony wrote 06/25/2018 at 16:07 point

I'm afraid Manta103g has a few good points, but I don't think they're show stoppers. For instance, it'd be great to have this machine fuel itself off the plastics, but, if that's gonna spew toxic gasses then maybe we can find a way to just compress waste plastic into bricks. In fact I think they're already starting to make houses that way, so, theoretically we could start pressing plastic into slabs that a table top CNC machine could cut pieces that snap together to make tiny houses, or even little bike trailers people can sleep in and lock their stuff in for security... 

Then we'd have something we could get known for, enabling us to garner the attention and social capital to build something even more sophisticated, such as a robotic decomposer.  What do you think?

  Are you sure? yes | no

Sam Smith wrote 06/25/2018 at 17:00 point

Manta103g does have a few good points, but they're not show stoppers, and it annoys me when people tell me so authoritatively that something isn't possible. 

To be fair, I'm learning too and by no means and expert, but I disagree with Manta103g's hot take, and with the caveat that I very well could be and am willing to be wrong, here is why: 

It's true that some plastics off-gas toxic vapors even when melted (not even burned). This is NOT true for all plastics, but it is for ABS, and it's true that ABS fumes from 3D printers are dangerous. It turns out that's actually caused by nano-particles or UFPs.

From wikipedia "ABS is stable to decomposition under normal use and polymer processing conditions with exposure to carcinogens well below workplace exposure limits.[20] However, at higher temperatures (400 °C) ABS can decompose into its constituents: butadiene (carcinogenic to humans), acrylonitrile (possibly carcinogenic to humans), and styrene.[20]

Lower temperatures have also shown that ultrafine particles (UFPs) may be produced at much lower temperatures during the 3D printing process.[21]Concerns have been raised regarding airborne UFP concentrations generated while printing with ABS, as UFPs have been linked with adverse health effects.[22]"

And all plastics, not just ABS, will decompose into a toxic smoke when heated.

But that doesn't mean that ABS cannot be safely decomposed into into a fuel, and in my mind, it actually is a decent argument for why ABS should be decomposed into fuel instead of being recycled, since melting/recycling it releases dangerous compounds whereas when used for fuel those compounds can be more easily contained. 

Check it out- ABS is Acrylonitrile Butadiene Styrene, chemical formula: (C8H8)x·(C4H6)y·(C3H3N)z). It's chemical structure is composed entirely of Carbon, Hydrogen, and Nitrogen. If you throw it onto an open pit fire, it will decompose into short-er but still fairly complex hydrocarbons, which can be all sorts of toxic compounds- styrene, benzen, toulene...

So don't do that! People have this idea that burning plastics is toxic, because it is when you do it in an open fire, at low temperatures.

If instead you shred ABS and heat it inside an air-tight reactor vessel, such that it gets hot and decomposes in the absence of oxygen, it will still break apart into smaller hydrocarbons, and some of them are toxic, but none of them are gaseous at atmospheric temperature and pressure.

If you cool the gas stream boiling out of the reactor in a condenser that cools the gas ALLLL the way back down to around 70F, which is what my condenser coil does, the only 2 compounds that remain gaseous at that temperature are Hydrogen (H2) and Carbon Monoxide (CO). 

H2 and CO are both combustible, and when mixed with O2, they combust into CO2 and H20- both non-toxic and 100% bio-compatible compounds. Now, I'm in favor of burning wood chips until I can guarantee the system is 100% safe and air-tight before working with more dangerous feedstocks, and I'm not there yet.

But ABS can in fact be thermally decomposed ALL the way back down to CO2, H20, and N2, and that makes those elements available to build built back into living things again. It essentially frees those organic elements so they can participate in the cycle of life again. 

And doing so releases heat, and also accumulates liquid hydrocarbons that condense out of the gas. I'm working on a centrifuge design that will sort them by their molecular weights, and then pump them into separate storage containers, so even the potentially dangerous ones can be stored without ever coming into contact with humans. 

The undesirable compounds- the ones that are either too heavy or too light to be useful by themselves, can simply be reflowed back into the reaction vessel, where they will break apart further into even smaller compounds, over and over, until they make it to CO and H2. And the desirable compounds- including analogues for gasoline and diesel fuels- can be filtered, stored, and used later as bio-fuel.

And the process necessarily produces waste heat and energy, which I intend to use to recycle as many of the other common recyclable and non-toxic plastics (HDPE, LDPE, PP, PET) into new objects- using molds, 3D printers, and extruders- which we could turn into building materials, and I think turning them into snap-together tiny homes is an awesome place to start!

Hope all that helps! Again, I'm not saying that doing any of this is trivial or easy, but I am saying that it is definitely possible, and I intend to figure out how to do it as best I can. 

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Michael Barton-Sweeney wrote 05/02/2018 at 16:56 point

Nice project!

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