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Energy Harvesting Through Footsteps

Project Guide: Prof.T.Judson Durai Team Members:Saran S.D, Sankar R.S, Sharon.M,Sherin Johnson

Department of Mechanical Engineering Noorul Islam University

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Energy Harvesting Through Footsteps

“A rack and pinion based device to convert the footsteps of the user into useful energy”

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Project Objectives To form an effective energy harvesting concept

To form a practically applicable system to demonstrate the energy harvesting concept

To design and fabricate the system

To test the system under various models

To find applications for the system

To explore further scope

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The NeedFast depleting natural resources

Coal is projected to enter production decline by 2030

Over dependence on coal based and other conventional methods for power generation

87.55% of India’s power production is based on non-renewable resources

60% of India’s total power production is coal based

Lack of adequate power supply Despite being the third largest power producing nation,300

million Indians lack access to electricity

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Energy Harvesting The process by which energy is derived from external sources,

captured, and stored.

The input is not deliberately created for the purpose of power generation.

Taps energy that otherwise would’ve gone wasted.

Usually produces low outputs, suitable for small applications

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Energy Harvesting Through Footsteps-Working Principle

• Faraday’s Law: “As long as there is a change in magnetic flux linked with the coil, an EMF is induced”

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Components Spring based suspensor

Rack and Pinion

DC Generator (Magnet & Coil)

Rechargeable Battery

Inverter

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Basic Design Step mounted on spring based suspensor.

Suspensor connected to vertical rack.

Rack connected to pinion ,whose axis is connected to a generator.

Generator is linked to a rechargeable battery.

Battery is connected to a inverter.

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Working User walks through the step.

Footstep activates the rack and pinion .

Generator connected to the axis of the pinion is activated.

An EMF is generated according to Faraday’s law.

Electric power generated is stored in the rechargeable battery.

Inverter module gives AC output .

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Footsteps

Rack & Pinion

Magnet & Coil

Rechargeable Battery

Inverter

Block Diagram

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Selection of Components Rack and Pinion

Rack and Pinion made of plastic

Rack has a length of 13 CM and has 65 teeth

Pinion has a diameter of 1.7 CM and has 15 teeth

Rack and Pinion sourced from a DVD drive

Selection helped save cost and weight

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Rack

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Pinion

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Selection of Components Suspensor Spring based suspensor Two springs of 5 CM length, 50 turns are used Springs attached to the plate containing the rack and a plate below

the rack. Connections made using copper harness

Generator A simple generator of 12 V output is attached to pinion. Output of the generator given to rechargeable batteries

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Suspensor

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Generator

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Rechargeable Battery Two lead acid batteries of dimensions 9.2x9.7x6.7 CM used.

Each battery having output 6V-3.5A, combined output of 12V-3.5A .

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Inverter Inverter used has two transistors Pulse Width Modulation Generator coordinates input to transistor Transistor supplies input to coils Coils convert DC from battery to AC

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Design

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Design Requirements

System must demonstrate power harvesting

System should withstand weight

System must be portable

System must have real time indication of power harvesting

System should demonstrate practical applications

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Steps in Designing

Design of support base

Design of Footstep

Design of Supports

Design of demonstration circuit

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Design of Support Base Support Base designed to hold the weight of the setup, and add

stability.

Flat surface with two protruding ends to act as stand

Dimension of 45.1x30x3.2 CM

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Design of Footstep Footstep designed to be retractable

One side of the footstep is fixed, other end being loose

Dimension of 18x5 CM

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Design of Supports Supports are designed in the shape of U

Two supports will be used to hold the steps

Dimensions 34.5x2 CM

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Design of Demonstration Circuit Designed to show the practical application of the system

Consists of generator, inverter and a household lamp

Circuit is triggered using a key

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Fabrication

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Steps in Fabrication Fabrication of support base

Fabrication of footsteps

Fabrication of supports

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Fabrication of support base Support base was fabricated out of wood

Wood was sawed off, and polished

Stands were nailed into the wood

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Fabrication of Footsteps Footsteps are fabricated using sheet metal

Sheet metal is cut and bend into the shape of steps

This sheet metal was screwed into metal supports

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Fabrication of Supports Supports are made from cast iron

Cast iron was cut using hack saw and later welded together

The cast iron was bend to form curves

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Final Model

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Testing

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Objective of Testing To assess the performance of the system based on the response.

Test Models Used:

Testing with different weights

Testing with different rate of weight application

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Testing with Different Weights To assess the performance of the system under different weights

Weights of 1 Kg ,5 Kg and 10 Kg were used

In all cases, consistent output of 12 V was obtained

Sl No

Input Weight (in KG) Output (in Volt)

1. 1 12

2. 5 12

3. 10 12

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Testing with Different Rates of Weights Intended to test the performance under different rates of weight

Tests were carried out at the rates 1, 5 and 10 steps per minute

In all cases, an output of 12 V was obtained Sl No

Rate of Footsteps (No.of times per minute)

Output (In Volt)

1. 1 12

2. 5 12

3. 10 12

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Observation Consistent output is obtained under application of different weights

and different rates

The model can be employed at used under varying load conditions and at varying rates of load.

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Applications Energy Generating Staircase

Self Illuminating Pathways

Burglar Alarms

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Energy Generating Staircase Multiple energy harvesting systems can be applied in staircases to

obtain a greater amount of energy

Can be used in shopping malls, railway stations etc

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Self-Illuminating Pathways Pathways that light up when user steps on it

Suitable for application in homes

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Burglar Alarms System can be hidden under carpets next to windows, doors etc

Burglar alarms can be connected to the system, which will be triggered upon unauthorized entry

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Scope of The Project Fabrication of more rigid system

Fabrication of supports with lighter and stronger materials

Multiple systems can be installed under staircases to harvest more power

Real time testing can be carried out instead of using weights

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Conclusion The rack and pinion based power harvesting system is found to be

effective

The system is cost effective and light in weight

The system has a variety of applications

The system harvest enough power for practical applications, without significant input

The system has large future scope

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Thank You