Project Summary
Everyday we see many people walking on footpaths in many cosmopolitan and metropolitan cities all around the world. Our daily lives today became so hectic and now there are no restrains on timings of pedestrians across the footpaths and zebra crossings.
Lets try to get an advantage out of this aspect. People start from their homes having good breakfast everyday. So, inside their tummies the chemical energy from the food what they have taken converts into ATP(Adenosine triphosphate) and gets stored in the body. This is converted to mechanical energy in the muscles of their legs when they start to walk.
So, why don't we convert this mechanical energy into electricity that can benefit all and help us in our daily needs like recharging cars, mobiles, traffic lights and street lights?
For this purpose I've designed a device that can be substituted in the place of a footpath tile. This looks like a concrete tile from the top but has a mechanism beneath it that can generate small amounts of electricity when someone steps on it.
About Me
I am Goutham Sharma, 15*. You can define me as a maverick, college goer, science enthusiast and an astronomy lover. I do things, ranging from home repairs where I use my brain to solve several 'home' problems like water leakage, clock repair, etc. to gazing at the night sky. From a tender age I have a avid interest in astronomy and space sciences along with robotics. I have followed a plethora of space missions ranging from the Apollo's to Mars Science Laboratory rover. I do read books and watch planets, track them with my camera, note down their positions, point my telescope to those planets, the moon and star clusters and question myself.
Questioning myself had helped me a lot in knowing about how things work, why do they exist and things like that. I am largely practical, I don't just read and know things but also test them, browse the web to know further about them and then confirm it. I strongly believe that life is all about knowledge and applying it practically for a better future.........
I also get involved in science fairs and projects at the school level and outside and have won few. Participating in this science fair, I think is not just about winning. Here I get an opportunity to showcase my innovations and imaginations I have been working out all the time and present it to the society which will take an advantage out of it to make this planet a better place to live and to work.
*as on March 22, 2012.
The Question
The main objective behind this project is to devise a new way of generating electricity and if possible to solve the present energy crisis we are having. So how do we convert mechanical energy into electrical just when a person steps on the footpath and goes for a walk?
Here we need to see that this does not pose any inconvenience or risk to the pedestrian and also the productivity should be in appreciable amounts at all times. We need to design a system which is integrated with all other systems such as the traffic, lights and primary safety.
Can this method solve our energy needs? Can we get any advantage from this?
Hypothesis
We are in the 21st century and all the way back from ages we have been employing new techniques ranging from wind mills to the present genetically modified viruses that can produce tiny pulses of current to try to answer our energy needs. The fossils are being quickly burnt and soon in the future they may get exhausted. I think that this method certainly will answer our need(though initially I have assumed it to be in short scale). Then lets try to think about even more functionality we can add to get the maximum output from this device.
Research
Extracting energy from the footsteps of a person sounds very interesting and I've recently found out that this type of devices are already being developed and being tested at various locations but I do not exactly know what mechanism was involved in them. So, I've decided to give what I've thought about the it. It may be different and in any other cases might exceed the capabilities of the recently developed ones. After all its just a suggestion from my side about a way of harnessing energy (might be in a different way).
Energy is generated in many ways and there seem to be even more possible ways as we pursue to do it. From mills that allow water from a stream to pass and come down thus turning the shaft that is connected to the grindstones via some gears that help in turning grains into flour to a recently developed technique where genetically modified recombinant viruses are used to generate short pulses of electric current that can light up a small bulb. Several ways have been all around us till now and we are even exploring more out of them.
Till now most of the techniques either use a moving fluid like water, steam or even air to move past a turbine that rotates the shaft of the generator or they make use of creating some potential difference across the circuit so that the electrons flow from higher densely point to deficient point like in the solar cells. Generating current may be in either ways, it may be in the form of alternating current or the direct current and this depends upon what sort of utility we have. For example for the purpose of recharging and for long range transfer into the city grid purpose we have to use AC current whereas for the purpose of other small scale purposes such as traffic lights or head and rear lamps of a bicycle, DC current needs to be produced.
So there needs to be two types of electric generators. In the case of this project we shall decide which one we shall use. It depends upon our utilities as well as partly on the relative cost of investing for this project by the respective agencies. It is also a matter of safety and this project is defined to be safe.
What I've seen in my research about several attempts to make this device come true is a company which has successfully designed and implemented it at some of the famous locations around the globe. This device glows when it is stepped upon and I've learnt that 75% of the potential energy with with it was stepped converts into electricity. Several of these devices can be connected into a grid circuit which can produce a great deal in a day of busy pedestrian traffic.
I guess that the difference in mechanism of the device which I am going to discuss later is going to increase to productivity further and this can be taken as a challenge to the former prototype and also It is not possible for be to do experiment on the pedestrian rate so I've took some data from some of the public domains about this for the estimation of electricity production but I can explain and construct the prototype of my idea in the next section.
Experiment
Here, I am going to discuss about the design and functioning of my brainchild. I haven't named it yet.
People step on it and the floor tile should send some real current to be recharged, that's it! It should be some sort of a springboard and beneath it there needs to be a mechanism. The condition is that when a person steps on it, reciprocating motion of the springboard should be converted into rotational motion of the shaft of the generator. So, the best example of this king of transformation is found in crank mechanism esp. slider crank mechanism. Here again we have to think about the overall mechanical advantage by which the angular velocity of the shaft is concerned otherwise it becomes a matter of less productivity and also its good to notice that the pedestrian should not feel bumpy.
For this, I will make use of a concrete tile(footpath tile) 30cm and 30cm in size. Beneath it to cover the generator and to crank gears lies a thin aluminium box measuring at least 30 cm down the pavement just along the tile. In the the gap between the tile and the box positions a spring which has a force constant so that at normal conditions(when its not stepped upon) it just keeps the the tile at least by 30mm (hope that is not too bumpy). Then inside the box lies not one small generator but a set of six of them whose shafts are fixed to a steel flywheel each measuring 6cm in diameter, this helps to conserve the angular momentum. The lower portion of the tile has six notches fixed with a connecting rod(20cm) each which is attached(rotated freely) to a point which is at a radius of 150mm on the flywheel away from the shaft (as shown in the diagram).
Its simply the same case of a steam engine's application in early locomotives whose enormous force was used to turn the wheels of the front engine which pulls the train forward.
For the purpose of the type of current we have to produce, a dynamo can be used because small dynamos today are capable of producing stable voltage and occupy less space. A dynamo produces direct current(current flows only in one direction). As earlier said we are using six dynamos together under a single tile. These dynamos have to be connected in series while each tile is connected in parallel. Here we have to understand that these group of tiles are not stepped upon simultaneously and the the timings may not be synchronized. All the tiles, in parallel are connected to a single DC inverter that can store the energy obtained by the means of rechargeable batteries and can be used later as per the user's wish.
The inverter also can be connected to a transformer can send the electricity to the power lines can can light up homes around the local.
Now lets turn to the topic concerning the productivity. It all depends upon the rate of pedestrian traffic and also the arrangement of the electric tiles on the footpath.
Now this is the diagram describing the entire design of the device:
Here, on the flywheels of the diagram, you can see the point O at their centers. Through these points shafts come out that are connected to a dynamo to produce current. As you see, the diagram is just schematic and under a tile in this manner we can fix six dynamos as a set together(two flywheels, as shown in the figure, but side by side i.e. 2into3). These dynamos are connected in series connection.
When someone steps on the tile, the spring gets pressed down, allowing the connecting rod, on the flywheel to to do half a cycle down and instantaneously, as the person lifts up his foot from the tile, the other half cycle gets completed i.e. one oscillation. This happens very quickly and turns the flywheel which is attached to the shaft(from O) of a dynamo. Since all the six wheels are attached to six dynamos, the efficiency thus increases six times compared to that of fixing just one dynamo. .
Two terminals protrude out of the device at the connection point beneath it. The other tiles in the grid are connected in parallel to the inverter since all of these do not have a chance of generating charge at once since they are normally stepped upon at random timings.
Conclusion
This is just the beginning and there should be even more support as far as the design and commercial support concerns.
My hypothesis was that this can truly benefit the people in terms of their needs and for the other uses. I think it is capable of what had been thought and regarding the design, I feel its unique in its own way. However, there needs to be support from the general public for the encouragement and maintenance of clean and green energy. Its our right to get it as cheaper as possible without harming our mother planet.....
Thank you
