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A Future Energy Alternative?

  1. Nov 1, 2009 #1
    Do you think that in the future we'll be able to create a device that can create energy just like how our bodies or any other living things do. Such as eating, drinking, and breathing.

    If not, then why?

    Sorry, if this is against the forum rules but I would really just like to know if this might be practical.
  2. jcsd
  3. Nov 1, 2009 #2


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    I would say a boiler does exactly that. It eats fuel, drinks water, and breathes air for combustion :rofl:.
  4. Nov 1, 2009 #3


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    Staff: Mentor

    Our consumption of food is essentially a combustion process like most of our energy sources - it's just how that energy is harnessed that is different.
  5. Nov 1, 2009 #4


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    Our bodies don't create energy. They convert it from one form to another and there are losses because of those conversions just like in any other conversion process.
  6. Nov 1, 2009 #5
    I don't get it. There are plenty of those around already. Horse, donkey, ox,...
  7. Nov 1, 2009 #6
    I wonder whether we could create a bio-engine that just 'eats up' any organic matter we put in-fruits,rice, wheat,meat whatever; produce heat energy just like any living entity and then the heat should be converted to electricity and stored in a cell. It should be sort of a compact box that could be placed behind the vehicle. When we stop by the side of the highway to get ourselves a drink, we need to share some with our Bio-E and get miles in return..
    The bio gas used now just makes use of the by product gases i think. In this case, the cell clump should work exclusively to provide energy to us. Any ideas to make this possible?
  8. Nov 2, 2009 #7
    This is what I was trying to get at.
  9. Nov 2, 2009 #8
    Hi there,

    I don't think I understand the question that well. You want to have a machine where we fill with fuel, and it would transform the energy stored in it to do stuff. Isn't that what a car precisely does: you fill your car with gas, it converts the energy into machanical motion and makes the car go vroum vroum.

  10. Nov 2, 2009 #9
    After the clarification it seems that a big part of the question is to do with the diversity of the fuel we can use for our artificial engines? As people have already said, we have plenty of artificial devices that do pretty much what our bodies do, they are just not as complete a process (waste, maintenance etc) or as diverse with the fuel they need.

    As an example, a solar panel is wonderfully simple in that it takes light and produces electricity, but it doesn't do much else.
    Likewise, a car takes petrol and produces kinetic energy, but doesn't do much else.

    A human body can take fuel from a lot of different 'unrefined' sources yet manages to produce a consistent output and manage at the same time things like waste and 'engine' maintenance. Perhaps the biggest difference is the intelligence it uses with which it seek out the fuel, deal with waste and generally just get on with things and be self sufficient, which machines currently dont do.

    In many ways, machines are like babies in that:
    -they need refined fuel
    -they need it giving to them
    -they also need somebody to deal with the waste!

    It's just a shame that machines don't grow up to become more diverse and self sufficient like humans do....... :-)
  11. Nov 2, 2009 #10
    The photosynthesis process for converting sunlight to food energy is very inefficient, susceptible to adverse weather events, and uses roughy 70% of fresh water consumption. Most of our food comes from C3 (Calvin cycle) plants (grains, etc) and is ~0.1% efficient in energy conversion efficiency. C3 photosynthesis stops at temperatures over 40 deg C. C4 plants (maize, sugarcane) are ~0.2% efficient. Compare to solar photovoltaic, which is ~20% efficient, and requires very little water.
    Bob S
  12. Nov 2, 2009 #11


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    Staff: Mentor

    I suppose we could do that now - you can burn food and other waste and get energy from it. Trash incinerators do it and like I said, that's basically how our bodies get energy from food. But food makes a rediculously poor fuel. Just think about how much waste our bodies produce and how little energy we get out of the food we eat! The human body generates about 150 watts or half a megajoule per hour - equivalent to about 11 grams of gasoline.
  13. Nov 2, 2009 #12
    preety much what I'm saying is that it can use organic material and turn it into energy?
  14. Nov 2, 2009 #13
    I beleive that organic matter contains about 5000 to 7500 Btu per pound, depending on its source. See biomass conversion numbers near the bottom in
    http://bioenergy.ornl.gov/papers/misc/energy_conv.html [Broken]
    I believe that public utilities can produce 1 kW-hour electricity from 10,000 to 12,000 Btu. Traditional coal-fired uttilities are ~34% efficient (10,000 Btu/kW-hr).
    Bob S
    Last edited by a moderator: May 4, 2017
  15. Nov 2, 2009 #14


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    Staff: Mentor

    Yes. What I'm saying is that whether it is oil or taco salad, the energy is the same: hydrocarbons. Oil is "organic material". Its just that oil has the energy stored much more efficiently than a taco salad does.
  16. Nov 2, 2009 #15
    But would taco salad be more environment friendly?:smile:

    But imagine if we can use something such as water as our energy supply. Our if we can harness chlorophyll and use it for energy. Can this one day be possible?
  17. Nov 2, 2009 #16


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    Staff: Mentor

    No, it is much, much worse. Probably an order of magnitude more pollution (depending on how you measure) for the same energy output.
    Water is not fuel, it is ash. It's the primary waste product of proper combustion.
    Again, we already do. That's what trees and oil are!

    Or if you mean harness it directly - same answer as above: it is a bad idea because it is very inefficient and the energy density is very low.
  18. Nov 2, 2009 #17
    It might be useful to compare the energy comsumption of people and automobiles.

    One gallon of gasoline contains 125,000 BTU.

    People burn about 500 BTU per hour sitting in a car.

    Let's say we have a fuel efficient means of transportation that gets 50 mpg and we drive for 50 miles at 50 mph. The energy cost is 125,000 BTU.

    The car requires 2,500 times as much energy. That's a lot of kibbles and bits.
  19. Nov 3, 2009 #18
    OK. Let's not get it from the humans. How about using the relevant cells and techniques of a particular animal that needs to do eat less, excrete less but exert more- say a cheetah or something else like that. Life should have found out a clever way for that animal. We need to just use it.
  20. Nov 3, 2009 #19
    is that a valid comparison though? shouldn't we look at work done seeing as the car is clearly achieving a lot more than the human in that one hour period?
  21. Nov 3, 2009 #20
    We already have a source of energy that runs indefinately and emmits absolutely no wasted or dirty bi products, accept when disposing of the highly toxic and slowly degrading uranium (1,000 odd years) uranium. My guess is nuclear energy will be the main substitute for fossil energy world wide and in the very near future.
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