Swamp Gas Will Get You Home

The energy to power a motorcycle has to come from somewhere, be it a power station, a solar panel, a gas station, or a hydrogen plant. There have been many ways to reduce the cost of extracting that energy over the years, but we think [Gijs Schalkx] may have hit upon one of the cheapest and simplest we’ve ever seen. It may not be free gas, but it is free swamp gas! His Uitsloot (we think that’s Dutch for “From the ditch”) motorcycle gets its power from methane generated in the sediment at the bottom of the Netherlands’ many waterways.

At its heart is a venerable Honda Cub moped, we’re guessing of the 50 cc version. On its pillion is a large clear container, inside of which is a balloon filled with gas. He doesn’t go into details in the video below the break, but we’re guessing he’s injecting the gas into the Honda’s airbox from which the engine can suck the gas/air mixture. We like his gas collector, a large inner tube with a collector funnel in its centre that floats on the water. He dons some waders and pokes the sediment with a long stick to release bubbles of methane. He then uses a long hose and a bicycle pump to inflate the balloon with the collected gas. We see him zipping around the streets of Arnhem under this unconventional power, though sadly we don’t see how far a full balloon will take him.

There’s a discussion to be had as to the environmental credentials of this project, but we think given that the naturally generated methane which would find its way into the atmosphere eventually has a greater effect on the climate than the CO2 produced by the engine, he may be onto a winner. It is however not a system that would scale to more than a few drivers poking at bogs with a stick.

61 thoughts on “Swamp Gas Will Get You Home

    1. I often visit the waterways here in flori-duh… and when you’re walking in the rivers and the delta, the bubbles coming up your legs and into your shorts tickle quite a bit. lol

    2. How does the small collection area under the inner tube hold enough methane to pressurize a large balloon? Eyeballing the apparatus I’d expect a much smaller degree of balloon inflation. Also, how did he know when to stop pumping? I saw no water enter the balloon. Not trying to call foul but I suspect the balloon is holding air. I saw the puff of smoke from the 2-cycle engine. You’d get that running an oil/gasoline mixture. Even automatic oil injectors mix it with the gasoline…

      1. On the site, he mentions that the engine still needs to be started on petrol (which he then switches off once the thing is running), and that it takes a full day of literal muck raking to collect enough gas for a 30 minute ride. It’s not meant as a practical form of transportation.

      2. The whole floating rig weighs a fair bit, so the gasses that collect won’t be able to escape by lifting the rig out the way, or go anywhere else – so that pipe and all the area of the collector underneath will pressurise itself somewhat as the floating lighter than air gasses collect – can’t lift the rig enough to escape but can compress somewhat – obviously at some point the pressure will blow bubbles out the bottom, but if the rig is heavy enough that won’t be quick – it will only take the collector to be a little more pressurised than ambient to expand the balloon to that sort of level after you pump it across. It also seems to be implied it wasn’t actually one poking session to fill the balloon.

        And that seal against the water is probably a good indicator of when to stop pumping – as you will start trying to pump a vacuum and suck the water up the collector – you will be able to feel it in the pump action – though you are almost certainly correct there is going to be a fair bit of air in that balloon done this way – unless you leave that rig up long enough for the lighter than air gasses to have pushed all the heavier normal air contents out the bottom…

      3. Inbetween the collecting apparatus and the moped there is a modified bicycle pump that pressurizes the balloon. There is not enough pressure within the apparatus and the gas itself to inflate the ballon which is also the reason I used condoms before while testing and experimenting, they don’t need any pressure device. Downside was a 10 liter limitation, which was only good for about a kilometer of driving. If you watch the video, it clearly shows the bicycle pump. As far as when to stop pumping: you will immediately feel it when you will pull up water through the line, you disconnect the line and the whole system will be depressurized, allowing air back in. One thing not shown in the video is bleeding the whole system though. Before harvesting I connect the pump, bleed the system of any air (pump until water comes through the lines) close the valve and disconnect again.


        Here is a video of the first test drive using harvested fuel, still using condoms and no pressure device inbetween.

    3. https://www.youtube.com/watch?v=DadLtvupYPg

      Check out the first harvesting video, start shows the amount of gas from a ditch. It depends a lot on time of the year though, warmer temperatures produce more gas and in winter time the production might even stop. Some ditches here in the Netherlands haven’t been touched for years and contain a thick layer of sludge, which then also contains a lot of gas. So it varies a lot depending on location and temperature but there is a lot of wasted fuel in our waters here.


      This article even talks about the hidden emissions of shallow waters here in the Netherlands, so it is an actual problem.

  1. Call me a skeptic. I see a small bottle of gasoline suspended on the handlebars and a portion of the video where he’s simply pedaling. Perhaps as a gross proof of concept this has some worth. I wonder at what kind of scale this would be useful; Individual rider, household, small community?

    1. He still needs some petrol to actually start the engine, that’s why the bottle is there.

      And he needs about 8 hours of harvesting to be able to drive about 30km.

      So it’s not too practical. ;) But he made it as final project for his university degree, and also to raise awareness for alternatives to fossil fuel.

    2. The gasoline is there for starting only, this little bottle has lasted me almost half a year now throughout the project.

      For scale, right now it would probably be individual is anyone else would actually want to harvest their own fuel for hours. A bigger and autonomous collecting device is being worked on though, which can be dropped in a pond and fuel can be collected later. Check out https://uitsloot.nl/infrastructuur/ for sketches and video’s of autonomous suggestions.

  2. Sorry but I don’t believe this is real.
    • If there was more than ~100ml of gas hidden in the muck inside a 1 meter circle, it would’ve floated free on its own
    • The collector device is way smaller than would be needed to fill the balloon to the volume shown
    • There are no visible bubbles around his feet in the swamp
    • If the engine was actually running “on” methane in the balloon, it would take ~ 50% of the volume shown just to get out of the park versus the 0% shown

    This is an art project

    1. This, it’s fake.

      Makes you wonder if it could be a workable concept though…maybe a floating machine that prods the muck, collects the gas, and burns it for energy right away? If it even makes enough to power itself, well congratulations, you’ve made a self-sustaining methane-to-co2 conversion anti-global-warming machine.

    2. You´ve never stepped in a swamp, didn´t you ? It can bubble quite a lot, especially if you tease the deeper layer where the gas is quite pressured. Easy to achieve liters of gas at ambient pressure. And don´t forget, the whole Netherlands is a bed of sand. Not just a superficial layer of mud on a bed rock.

      And you did not care to read the link provided, so I´ll to the digest for you, skeptical pedestrian:
      – it´s a 4 stroke engine
      – he can get 5km on a charge
      – between the handlebars is a oil tank, for the splash lubrication.

    3. Some handkerchief calcs for the sceptical:

      During testing the engine runs an average of 4000 RPM
      It’s a 50cc 4-stroke engine
      He runs on average 50% throttle, filling his combustion chamber with 25cc of air-fuel mixture each power stroke

      25cc * 0.5 * 4000 RPM = 50.000 cc/min of air/fuel mixture pumped through the cylinder
      50.000cc/min = 50 litres per minute
      Volumetric stoichiometric ratio of methane is roughly 1/10, so methane required is roughly 5 litres per minute.

      Eyeballing his condom… eh balloon, that would contain roughly 50 litres, I guess?

      That would give him about 10 minutes of riding time. Not much but it’s something =)

      Also, the “UitSloot” means literally “From Ditch”, but sounds like “uitstoot”, which means emission. It’s a pun.

      And like vib says, most bogs in the Netherlands are like peat bogs, most of them got over a meter of decaying plant matter at the bottom. Don’t step in that, you can quite easily disappear even when the water seems only 20cm deep!

      1. Thought the balloon looked dubious but glad someone else called it out :)

        It does seem a wee bit dubious that so much gas could be collected over such a tiny area also from a pond that clearly didn’t bubble much (if at all) where he was walking.

      2. In the movie, there are more puns written on the signs (Plompstation refering to gas station (pompstation), plomp being slang for ditch; Prof. Eet refering to a prophet and eating). Arnhem is known for Loesje posters, where refreshing humor is captured in a few words on A4 format. This smells, apart from swamp gas, after an art project. Marvellous. Also the gas inlet on an ordinary bike pump.

    4. He mentions that the engine still has to be started on petrol; it takes him 8 hours to collect enough gas for a 30 minute ride so it’s obviously not meant to be practical. Maybe actually read the site / watch the video before crying foul?

    5. Hey RP, and others, maker of this project here.

      Yes, it is an art project. But is is also fully functional and real. If you don’t believe me, I suggest you to check out my site (www.uitsloot.nl) and my youtube channel, which contains all video ”proof” (as far as video is still proof these days) of the whole process from start to end.

      Here is a Dutch newspaper article talking about methane emissions from shallow waters (ponds, ditches) so there is definately ”fuel” in the bottom of them. I found a story about a fishermen who put a bucket upside down behind his boat before he went fishing. After he caught some fish, the bucket would’ve also filled with gas which he then used to fry the food. This is where the idea came from, together with experiments we did when we where younger, burning our eyebrows off trying to make flames with a bucket and a stick.


      The collecting device is indeed to small to fill the full balloon in one go, it can collect about 75 liters at a time, meaning i need to fill it 3 times to fill the balloon (fuel container is around 200 liters). For the video you have seen, I filled it once.

      Depending on time of the year there might be more or less gas in the organic matter, it very much depends on the temperature. I started the project in the winter, when there was barely any gas and the gas that i did collect contained very little energy at the time (more co2 than actual CH4).

      The moped runs about 1:75 on gasoline (kilometers, not miles) with a well-adjusted carburetor. A liter of gasoline contains almost the same amount of energy as a kilogram of CH4, which is almost 1 m3 (also dependent on temperature ofcourse). In theory the moped could then drive 15 kilometers with 200 ”liters” of fuel (full balloon). Truth is that methane (in high concentration) burns better than gasoline and you can bypass the carburetor and mix it yourself. Better combustion ratio = better mileage, right? I have driven a kilometer with just 10 liters of methane, so 20 kilometers should be doable with 200 liters.

  3. I think this isn’t that bad for the environment, Methane has 34 times the global warming potential of CO2 but when burnt turns into CO2 (CH4 + 2 O2 → CO2 + 2 H2O) so by burning it instead of releasing it into the atmosphere we are reducing the greenhouse effect of emissions. And if you’re not near a bubbling bog you could always try this…


    But if you live in the city to get this to work you’ll need to increase your fiber intake.

    1. I wonder how much methane gas can be harvested from the sewer system. :) Free methane gas, your whole neighborhoud working to produce your gas for you. For free! :P

    2. It is actually 900% green energy, compared to carbon-neutral energy.

      The 34 times is a number under heavy discussion, right now 25 is considered the GWP (global warming potential) of methane. But it is actually not 25 times as good as doing nothing as a kilogram of methane results in 2.74 kilograms of CO2 after combustion. As a result, it is 9 times better than doing nothing.

      Taking away sources of methane also has a much bigger effect on global warming than trying to restrict / capture CO2, as capturing methane has a cooling effect for the environment. This combustion engine cools down our planet ;)

      Check out https://uitsloot.nl/de-verkoelende-formule/ for the whole formula.

  4. Methanogenesis is an anaerobic process!

    So I could see a commercial methane farm being the end result. It would still need to be fed biomass to work, so provided there are no leaks it would be a carbon neutral technology. But the farm could be built vertical near a cheap source of unwanted biomass.

    1. You’re more or less describing anaerobic digesters. They’re mostly fed wastes from agriculture or industry to partially clean them up, and make biogas in the process. The biogas is often used for both power and heat for on-farm buildings. I’ve seen a fair bit of talk about powering vehicles with biogas.

      1. In the 1970’s there were pictures in newspapers of chinese buses being run from biogas carried in giant bags full of compost on the top of the bus. (Bags larger than the bus.)
        My recollection is that there were issues with clearance because of overhead lines, and issues with buses in many parts of the world using their tops for cargo/cheap seating, so lower fuel costs were somewhat offset by lower fare revenue.

        1. China is world leader in biogas and particularly household biogas:
          cooking, metal smelting, lighting, and even for refining salt (…)
          And this all started … 2000 years ago.

    1. Does not look like a Cub to me, they were almost as hefty as the similar C70 and C90.

      In UK though, sub 50cc limited output motorcycles are “mopeds” for classification reasons.

    2. The yellow license plate in the Netherlands classifies it as a “heavy” moped. (vmax above 25 km/h, helmet required)
      The Dutch Vehicle Registration website says it’s a “Honda SH 50” but it looks a bit older than that. But the vehicle registration can be quite sparse for older vehicles, especially mopeds which weren’t nationally registered before 2005.

    3. It is actually a PC50, Dutch ”lady” version of the C50. Here in the Netherlands, mopeds needed to have pedals in order not to qualify as motorcycle. It is powered by one of Honda’s 50cc pushrod engines, which can be found everywhere. I recently picked one up in working condition for 25 euro’s in case my current one dies. Need to take of the head and check the valves soon to see how they are dealing with different fuels.

  5. For those not fluent in Dutch, there are a few word jokes to miss:
    * Uitsloot (litt “from ditch”), which is also one letter away from uitstoot (emissions).
    * The sign at 0:39 reads Plompstation (litt “bog station”) but is one letter away from pompstation (pumping station, an old-fashioned word for gas/petrol station)
    * The sign also mentions it’s an initiative from Prof. eet (“Professor eat”) but profeet as one word is prophet.

  6. So the vast coal seam gas project of the Surat Basin in Queensland Australia is a good thing then, because it is also extracting methane from an ancient swamp so that it can be used to produce energy as it is converted to CO2? Coincidently that project is 50% owned by Royal Dutch Shell.

      1. Yes it is, it bubbles up in some of the rivers in that region so it can be expected to be doing the same across the entire region. It is actually held in the coal bed by water pressure so if that alternates seasonally you can expect a response. A bit like having an elephant living under your couch and you never realise it is there, until it farts.

  7. I call fake.

    Pond scum doens’t produce just methane, but mostly CO2 so he would have troubles even getting the moped to run with an unkown A/F ratio needed to combust the fue. He seems to have perfectly normal power from the moped, which indicates he is running on normal fuel.

    1. A typical digester produces around ~60% methane and around ~40% carbon dioxide. While these rates do vary depending on the feed, biogas in itself is combustible but would burn cleaner with the CO2 removed. Biogas typically also has trace amounts of hydrogen sulphide, which will kill the engine in the long run if it isn’t filtered out.

      As for the A/F ratio, I would not be surprised to see an engine run fine after it has initially been trimmed for the new fuel.

      1. The methane is low grade power density wise, so we used diesel to start the turbines, and once up to speed, switch to the low grade methane. As per EPA regulations, the exhaust was compliant as to emissions

    2. CO2 is produced along with methane, and biodigesters running fast make a lot. But here, sitting in the water, the CO2 slowly dissolves leaving a higher concentration of methane. I have collected this in an australian dam to amuse.

    3. The CO2 to CH4 ratio varies A LOT, depending on temperature. When I started in the winter, it was indeed quite hard to get to moped to run normally and power was very low. (first actual test drive: https://www.youtube.com/watch?v=SIKkaawKi8M&t=35s) I actually felt like it became an 8-stroke, skipping combustion every other cycle. It also contains hydrogen sulphide, which can easily be filtered out with steel wool filters which are in the PVC tube on top of the collecting apparatus. In summer time, the CH4 content was a lot higher, making the engine run actually better on methane than on gasoline (45 km/h rather than 35km/h). Next to that, the a/f ratio is mixed by hand. Throttle opens the air valve while the little handle in the middle of the moped opens the pressure valve for the methane. This way you can adjust it for any kind of a/f ratio, so top speed might be 45 km/h on good fuel, you can always adjust it for ”bad” quality fuel.

  8. My 20 years with Los Angeles County, we used “Poo Gas” from the sewer system. This was used to generate power to run the plant, and then any excess was sold to Edison. Our landfills provided methane gas from decomposing biomass. This second source was used to generate electricity and sell to Edison. In both cases, we were required to remove the offending gas and use it safely or pay fines. Around the planet, I hear of hydrated Ch4 being used. (Frozen Methane down low)
    And yes, the methane from both sources is low grade power density wise, so we also used diesel to start the turbines, and once up to speed, switch to the low grade stuff.

      1. Our systems were both large and small. I built the first one, putting out a low 2MW. Next we installed some larger turbines, running at 10MW. We had several steam turbines running, rated at 10MW up to 50MW.
        To be clear, the steam turbines burned the methane directly in a large boiler, making the steam, and spinning the turbine. (No diesel required)

  9. For the naysayers, look at what happens when our drainage ditches are frozen over. You often see bubbles of gas sitting under the surface, and you can light them as shown in this video: https://www.youtube.com/watch?v=hmE7eO9N2nI

    If you disturb the layer of sediment on the bottom (often a mixture of grass, tree leaves, sometimes agricultural runoff), pretty much always some bubbles of gas come to the surface.
    Collect enough bubbles and you can run an engine on it.

    If you drill a well down to the ancient sea water trapped below the sand/clay layer, you can separate the water and the gas with a shower head-like system, and get enough gas for cooking and lighting. Hundreds of farms in the Beemster polder used that system until the natural gas network was completed.

  10. When I was in the UK, people were trying to run their engines using discarded oil from restaurant kitchens. A form of bio-diesel, I guess. But the authorities found out about it and realized that the people who were doing this were avoiding the transportations fuels tax. So they went after them. Apparently they were easy to find because the vehicles gave off a smell similar to French fries. The cops who pursued these law-breakers came to be known as “The Frying Squad.”

    1. People still run their cars on bio-diesel made from fryer oil in the UK. You have to start paying tax on it if you make more than 2500 litres per year, I guess that’s a fairly good cutoff between ‘personal use’ and ‘industrial use’.

    2. Cool! I am also trying to start producing my own Diesel, as the Diesel engine was once designed to run on bio-diesel, but in recent years has gotten quite a bad reputation as big polluter.. Rudolph Diesel would be ashamed today.

    3. Bio diesel has never been a player.. The “Vapor Point” is too high, requiring a heated fuel tank and other not too cheap fixes. Diesel itself has a high vapor point, but doesn’t need the tank heated as it’s not as high as bio diesel..
      What’s amusing, the signs on diesel tanks that read “Flammable” . All firemen know the best way to put out a road flare that’s burning, is dunk it in a bucket of diesel.
      (The vapor point charts are out there, look it up)

  11. Gijs, thanks for sharing, linking to your website (it’s easier to browse than hackaday.io!) and for coming on here to clear up the questions. It’s a really cool project, and sounds like it is uniquely suitable to your area.

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