It's the future and oil resources have run out. A scientist has suggested using personal fart power to meet our individual power needs.

World governments are seriously considering this. They have identified a strain of genetically-modified bean that is easy to grow and results in an incredible degree of flatulence. Additionally they are developing some 'friendly' bacteria that show signs of being able to fartify pretty much every kind of foodstuff. Crucially it doesn't produce smelly farts - just very voluminous and flammable ones.

A study is in progress whereby volunteers are wearing fart-packs strapped to their rear ends whilst driving, and these are connected to their car engines. At the moment the fart gas is being used to supplement the conventional fuel. However the scientists hope eventually to power cars entirely by the farts of the driver and passengers. Other applications are in the pipeline.

How workable is this? How would society react? Bearing in mind that, with the new bacteria, the smell is negligible and also that the equipment is designed not to let the farts escape into the atmosphere, what would be the downsides?


  1. Speculative answers are welcome but ideally I'd like some science or even hard-science as well.

  2. This is a separate question from collecting farts from cattle. The whole idea is that you have your own power pack with you at all times and it uses your own emissions.

Addendum It has been pointed out that constant farting whilst not using the resultant gases could be a problem. That is true but it is not insurmountable.

The bacteria is quick acting and very efficient, especially in conjunction with the beans. When planning a long journey, you simply take your day's food supply with you. Then you eat sufficient to last for the next leg of the journey. People will become expert at judging just how much they should eat to get to Aunt Ada's house, flatulence free.

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    $\begingroup$ "fartation" => flatulence. $\endgroup$ Jul 25, 2015 at 23:28
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    $\begingroup$ Mixing ass comedy with reality check and science based and hard science is even more funny ;) $\endgroup$
    – Mithoron
    Jul 25, 2015 at 23:39
  • $\begingroup$ @LorenPechtel - thanks, I've changed it. Any suggestions to replace 'fartify'? $\endgroup$ Jul 25, 2015 at 23:56
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    $\begingroup$ @user6760 - Because it's much harder to store and distribute farts through commercial outlets than it is petroleum. The whole point is that, wherever you are, you have your own lab right there with you. This does away with the need for petrol/gas stations. All you need is to eat. Eating is necessary anyway so it seems an efficient way of going about things. It also keeps farts out of the atmosphere. $\endgroup$ Jul 26, 2015 at 0:02
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    $\begingroup$ For reference, because you really want to know... as studied in Investigation of normal flatus production in healthy volunteers. the average, healthy, human male eating 200 g of baked beans in addition to their normal diet produced an average of 361 ml of hydrogen per day and up to 120 ml of methane (this is dependent on intestinal flora). $\endgroup$
    – user487
    Jul 26, 2015 at 15:55

7 Answers 7


The big problem with using flatulence for power instead of petroleum is that food has a lot less energy than petroleum products. A gallon of gasoline contains roughly 30,000 calories worth of energy, which is roughly comparable to the number of calories a person could consume daily under the most extreme circumstances. Even then, consumption of this many calories would be unsustainable for human physiology.

A gallon of gasoline per day isn't particularly useful, especially if it can't be produced and stockpiled. After all, storing it means you're wasting energy compressing or otherwise bottling the methane, and you have extra weight to cart around.

You've also got to spend a lot of energy growing the food and getting it to people. Modern food production and distribution is energy intensive, and you're talking about a ~10 fold increase in the amount of food that needs to be distributed to the consumer. On top of that, without petroleum you can't (efficiently) produce modern fertilizers that give us our current crop yields.

You would probably be better off just giving everyone bicycles and keeping them on their current diets. Or even burning the food itself for energy instead of reprocessing it into methane.

If you insist on going the methane route instead of creating bio-diesel or alcohol (which are arguably easier to handle and use), you're better off doing it on an industrial scale located where the crops are grown instead of in the human body then distributing it from there.

  • $\begingroup$ +1 I was visualising everyone having their own bean patch in which they grew the special beans. They would dry them and build up stores for use on journeys. The special bacteria could be cultured locally quite easily or they would simply exist in one's digestive tract, dormant whilst waiting for the beans. Thus you could set out on a journey equipped simply with dried beans. Note, I am assuming that water is readily available at all times. Under these conditions and given an optimised vehicle but no other source of fuel, are you saying the amount of gas wouldn't be enough to drive the engine? $\endgroup$ Nov 6, 2015 at 15:38
  • $\begingroup$ You could maybe - maybe - drive a supplemental electric motor on a bicycle by processing the methane through a fuel cell. That would be about it though, and you would probably still need to pedal to get moving and get up hills. $\endgroup$
    – zagdrob
    Nov 6, 2015 at 16:11

Farts are produced by fermentation of food within the digestive tract. Even assuming you can bioengineer perfect bacteria which can convert food energy to methane with 100% efficiency, it is still completely meaningless to perform the fermentation within humans, instead of in a controlled environment within industrial fermenters.

An industrial fermenter can be kept sterile, away from any pathogens or contaminants which can reduce the yield of methane produced from the feedstock. It also allows one to power the bacteria with cheaper food sources, instead of whatever the humans eat. It can also handle much higher pressures than the gastrointestinal tract before rupturing.

Using the human gastrointestinal tract to bioferment methane would also result in significant safety issues. Leakage of methane when not coupled to the gas extractor would result in burns, explosions, and other dangers when ignition sources are nearby.

Therefore, even assuming such a system is possible, there would essentially never be a reason to use the human gastrointestinal tract as a biofermenter.

  • $\begingroup$ Thanks for your comment. Don't forget that this is the age when there is no petroleum left. The production and compression of methane followed by its distribution to outlets is an expensive business. Having your personal supply of gas cuts out the middleman and allows anyone access to power for little more than the cost of eating. $\endgroup$ Jul 26, 2015 at 8:50
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    $\begingroup$ I've just added to my answer to deal with the excess gas when not connected to the extractor. $\endgroup$ Jul 26, 2015 at 9:07
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    $\begingroup$ @chaslyfromUK nothing would stop people having their own personal bio-reactor somewhere. There is no reason to do it inside their own body though. Also they are still dependent on food/water, even if they don't need fuel as such they need it in the form of stuff to turn into fuel. $\endgroup$
    – Tim B
    Jul 26, 2015 at 18:34

To answer the question "how would society react?", I would imagine that it would definitely not catch on unless all other forms of power were ridiculously expensive and there was an emergency.

Logistically you've got to consider that people would have to be eating A LOT of beans to produce a useful amount of methane. You would also be farting all the time, not just when you're driving your car. Are you expecting people to keep a backpack of bottles with them? Shove tubes up their ass? Put up with eating beans all the time and farting non-stop?

The idea I'm afraid is 100% unviable.

  • $\begingroup$ I've added the proviso that people can eat the produce specifically just before they need the power. $\endgroup$ Jul 26, 2015 at 21:37

While other answers have pointed out problems with the premise, I am answering on the assumption that it is possible. It must be possible, if only to fulfill the dreams of small boys everywhere of a world that runs on farts. Ahem. Anyway...

Variation on the premise: While it was initially reported that a miracle bacteria was responsible for efficient flatulence, the masses were too desperate for an energy source that they didn't question this claim too deeply. By the time skeptical voices circumvented the censorship that had been silencing them and pointed out that no amount of human farting could produce the energy people were now drawing from their buttplugs, it was too late: over 90% of the population had already undergone the procedure.

The truth is that we were not given bacteria, but rather a specially bio-engineered parasite whose waste is a previously undiscovered, incredibly energy-rich compound. We were unable to reproduce this compound in a lab and the parasites could not be engineered to live outside of a human host, so we had no choice. They live inside of us, consume 100% of what our bodies don't need, and add their waste compound to the host's farts. We call them "Nibblers," because the scientists behind the project were Futurama fans.

While there was an initial outrage when the government deception was discovered, the public quickly forgave the crime as they grew to embrace the Nibblers inside them. Life was so much easier now! No longer did anyone have to worry about watching what they ate. The nibblers consumed everything we didn't need and could go without food longer than we could, so there was always energy when we wanted it but we never had to eat extra just to keep up with their appetites. While the health and fitness industry collapsed, the food production industry more than compensated, exploding until it commanded over half of the workforce. The restaurant industry also surged, and parents loved to tell their children while dining out that when they were young, there were restaurants called "buffets" where you could eat all you wanted.

The toilet paper industry also took a hit, as people no longer needed to poop anymore, but stabilized at the new lower level that was enough to support female urination. (Nibblers convert 100% of what we eat and don't use into gas, but we still pee out excess water, because otherwise the earth would run out of water and who wants to deal with that can of worms?)

The buttplugs permanently implanted into everyone with a Nibbler include a fart capacitor, which stores all energy contained in our flatulence until we sit on an energy absorption pad to power a device. Once the energy absorbed, the remaining portion of the fart that is expelled from the buttplug is undistinguishable from the existing mixture of air in the atmosphere. Children often enjoy attaching constricting covers to the exhaust port so that their farts whistle.

While the Nibbler/buttplug combination was a successful solution to the energy crisis and overall regarded positively, there were, as always, unintended consequences. A significant portion of male homosexuals refused to accept the procedure, even after the Supreme Court ruled that the device did not infringe upon their rights. (As Justice Scalia wrote in the majority opinion: "You've got a mouth.") While some of these men were able to excel in business and live by purchasing the farts of others, many were subjected to poverty by their refusal to undergo the procedure and, with help from certain Amish communities, began living in technology-free communes. There was also a disturbing rise in sex trafficking, as those with unobstructed anuses became a rare and valuable commodity to this trade.

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    $\begingroup$ Haha, great answer! I think this one is more in tune with how funny the initial suggestion actually is. $\endgroup$
    – Varrick
    Jul 26, 2015 at 23:13
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    $\begingroup$ Thanks, @Webkanguru. That's what I was going for. I've spent most of my time here discussing ethics, relativity, religion, chemistry and magical science, but then I read this question and it revived the five year old boy in me who always tried to fart when his mother said she needed gas. $\endgroup$
    – Josh
    Jul 26, 2015 at 23:53
  • $\begingroup$ Converting 100% of unneeded substances into useful gas is pretty much impossible; food consists of more than hydrogen/carbon/nitrogen/oxygen. It's got all sorts of trace metals, and I don't think you could easily convert them into gasses. $\endgroup$
    – D M
    Nov 24, 2017 at 17:27

Any serious proposal along those lines would use biogas generation, with human biological waste just one raw material. The idea to use the human stomach as a bioreactor sounds not just gross, it will be impractical from an engineering viewpoint.

That's one of the problems with The Matrix, too -- humans are not efficient power plants.

  • $\begingroup$ Thanks for your answer. I'd be interested to know why it is a difficult engineering problem. Under the driver's seat there is a reservoir in the form of an impermeable gas bag. Farts add to the reservoir and the engine draws from it. $\endgroup$ Jul 26, 2015 at 12:02
  • $\begingroup$ +1 for the impracticabality of the issue, but it seems that the OP intends the bacteria to be doing the power conversion instead of the humans, and bacteria can convert food to energy more efficiently than humans can. $\endgroup$
    – March Ho
    Jul 27, 2015 at 2:22
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    $\begingroup$ @chaslyfromUK That's great until you have to get out of the car. With the exception of long-distance truckers and some other professions, people spend only a small minority of their time driving. Unless you're proposing everyone walks around wearing backside-mounted gasbags at all times? $\endgroup$
    – user867
    Jul 27, 2015 at 6:38

Farts just don't have enough power per volume for this to be feasible. I think the average person produces 2 liters per day and that is no where near the amount of natural gas burned by a city bus powered by natural gas in an hour.

  • $\begingroup$ Thanks. I wonder if you could explain a little more fully. I didn't envisage a bus being powered by a single person's farts so it doesn't seem to be a straight comparison. Maybe buses would have to be powered by a full complement of passengers. They wouldn't be able to run on just the driver's emissions. Do you have numbers for the bus as well as for a single person? $\endgroup$ Jul 26, 2015 at 8:45
  • $\begingroup$ Can you add sources for that? Thanks. $\endgroup$
    – HDE 226868
    Jul 28, 2015 at 22:14
  • $\begingroup$ @HDE226868 bing.com/… $\endgroup$
    – HSchmale
    Jul 28, 2015 at 22:18

Timing my own, on average my farts last approximately 1 second. The average fart produces .0367 kCal of energy. Let’s assume that due to the enhanced bean tech we’re looking at 10 times that. I’ve got to assume these farts are well above average. There are 86,400 seconds in a day, so based on my 1 fart per second average and the average energy in a fart. a full day farting produces 3,170.88 kCal of energy. At the 10x energy rate we’re looking from enhanced bean tech we’re looking at 31,708.8 kCal of energy, just over one gallon of gasoline worth of energy.

This means we need to heavily, if not almost entirely rely on the fart producing bacteria. For this to be viable the fart gas needs to be harnessed and pressurized. To be continued...

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    $\begingroup$ This is a great beginning to an admittedly tongue-in-cheek question (could you imagine the discomfort of passing gas 24/7?). Please don't forget to specifically answer the OP's question (viable or not?). There's a "no" building in your answer, but you haven't said it yet. Otherwise, well done for your first post on WB:SE! I look forward to the rest of your answer and your continued participation on the site! $\endgroup$ Nov 24, 2017 at 5:09
  • $\begingroup$ Welcome to WorldBuilding! Interesting start to an answer, but please edit to append the end to it. If you have a moment please take the tour and visit the help center to learn more about the site. Have fun! $\endgroup$
    – Secespitus
    Nov 24, 2017 at 8:13

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