A white paper on Energy Harvesting from Human Footfalls

1. Harnessing Kinetic Energy from Footfalls
Harnessing Kinetic Energy
from Footfalls
Scope e-Knowledge Center Pvt Ltd
May 2014

2. Harnessing Kinetic Energy from Footfalls
Table of Contents
1. Energy Harvesting from Human Footfalls..............................................2
2. Footfall Energy Harvesting Floor – A Brief............................................3
3. Experiments with Energy Harvesting Floors.........................................4
4. The Technology behind the Energy Floors............................................5
5. Piezoelectric - The Preferred...................................................................6
6. Market Analysis........................................................................................7
7. IP Perspective...........................................................................................8
8. Conclusion..............................................................................................10

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1. Energy Harvesting from Human Footfalls
With the electronic devices becoming integral part of day-to-day life, both in personal and industrial
environments, the demand for energy is tremendously increasing across the globe. In the effort to find
alternative sources to supplement the conventional energy sources, the energy industry has found the
feasibility in fossil fuels, nuclear, thermal, hydro, solar etc. The researchers’ quest for eco way of
generating energy has found a destination at the feet of fellow human beings.
Human body generates a lot of energy while doing the most-common activity - walking. Every foot fall
causes pressure when the foot hits the floor, which goes untapped. With the ground surface engineered
to harvest the energy, power can be generated from the human footfalls, stored and used as a power
source or even fed to the power grid. For instance, a person dancing on an energy harvesting floor can
generate 5-10 watts; in a packed dance club, the production can meet up to 60% of the total energy
required for the club.

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2. Footfall Energy Harvesting Floor – A Brief
Sustainable energy is the buzz word in the energy industry, and an emerging technology in the industry is
the footfall energy harvesting floor, which generates energy from the routine human activities, such as
walking, running, jumping, dancing etc. The technology works on the basic principle of converting kinetic
energy, obtained from the pressure applied on the floor surface, into electrical energy. The “footfall
energy harvesting floor” comprises a floor covering that encloses a transducer mechanism for converting
the applied pressure into electrical energy and a means for transmitting the electrical energy for storage
or load consumption.
Among the other technologies that promote sustainable energy, energy harvesting floor is considered to
be the most productive as it does not depend on any of the natural resources, such as wind, water or sun
that are not consistently available. Energy harvesting floors, which take input from human footsteps
without affecting pedestrians’ normal life, are easy to install, environment friendly, and are truly
sustainable.

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3. Experiments with Energy Harvesting Floors
Over these years, researches and developers have experimented on footfall energy harvesting floors to
study their feasibility, reliability and effectiveness. Constant experiments have been carried out in the East
Japan railway stations, streets of Toulouse and West Ham underground station over a period of varying
durations, ranging from several weeks to few years. These experiments have provided evidences that
energy harvesting tiles are robust, practical and can be used as an alternative source of producing
energy. Post the initial success, improvements are being made and tested for enhanced power
generation performance and capacity, along with advancements in material durability. The energy thus
captured can be used to power streetlights, pedestrian crossing lights, bus stop displays, traffic signals,
automatic ticket gates in stations, information displays etc.
Dance clubs around the globe have piloted the footfall energy harvesting floors belonging to the prototype
concept - "Crowd Farm", in which energy from footfalls of clubbers dancing on the floors is collected and
used to power LED lights and, in the long-term plan, fed into the club's power grid.

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4. The Technology behind the Energy Floors
With this method energy harvesting proving its feasibility, developers of energy harvesting floors
concentrating their efforts find the most-efficient way of harvesting energy from footfalls. As a result,
several inventions are in the prototype stage. However, some industry players, with the aim to popularize
and establish this technology among varied consumer segment, have already initiated marketing of their
products, which has been well received by environmental activists.
Based on the mechanism used for converting the kinetic energy into electrical energy, footfall energy
harvesting floors can be broadly classified into the following categories:
Piezoelectric
A piezoelectric element like PZT, PVDF, etc., is used as transducer means to convert the
kinetic energy into electrical energy upon stepping on the floor tile. Deformation of the
piezoelectric element caused by the load acting the tile induces charges which can be
siphoned off.
Magnetic
Transducer means comprises a magnetic element and a conductive element, wherein
one of the elements is movably coupled to the floor surface. When a pressure is applied
on the floor surface, the conductive element cuts the magnetic flux and so current is
induced in the conductive element.
Generator
A mechanical arrangement viz. hydraulic, pneumatic and spring is coupled to the floor
surface, such that a rotor of a micro-generator arranged in the floor tile is driven by the
mechanical arrangement when a force acts on the floor surface.
Static
A capacitor is formed in the floor tile by using two charging layers uniformly separated by
a small gap, wherein one layer is coupled to the tile surface through springs. By pressing
the tile surface, the gap between the layers is altered and so charges are induced in the
layers. These charges can be extracted by suitably connecting the layers to an external
circuit.

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5. Piezoelectric - The Preferred
Though various kinds of footfall energy harvesting technologies exist, piezoelectric is the commonly-used
technology. It generates energy from external force impulses or vibration in flooring, bridges, roads and
structures. The other potential sources of piezoelectric energy harvesting systems are deformable objects
such as golf balls. This system can produce energy even with consistent or predictable vibrational
frequency. With its ability to leverage any kind of force, stress or strain, it is ideal for different applications,
and hence has a widening market potential.
The investment on piezoelectric energy harvesting is expected to reach US$145 million by 2018, and
thus, by 2022, it will be a US$667 million market. Though, power generated using piezoelectric systems
are predominantly in cigar lighters, they have found applications in wireless sensors and various portable
electronics.
However, the varying or inconsistent vibrational frequency range limits the practicality for certain
applications.

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6. Market Analysis
Energy harvesting (EH) has become a major area of focus in Europe and North America; Asian
organizations too are investing in the various EH technologies. By 2020, the global energy harvesting
market is expected to reach $4.4bn.
Majority of the sustainable energy technologies calls for a constant monitoring of, the surrounding
environment of installation location. Further, the suitable type and specifications of the devices has to be
decided based on the survey reports. Parameters such as size of the devices and place of installation
also mandate the tedious, time and effort-consuming post-installation monitoring and maintenance tasks.
In contrast to other technologies for which locations are decided based on surveys conducted over a
prolonged period, energy harvesting floors eliminate any pre-installation analyzing or monitoring to
identify the ideal location. The sole criterion to be fulfilled for the installation is that the place should have
human movement. Every city around the world has a huge, growing population, and public places like
airports, railway stations and commercial complexes receive huge amount of footfalls throughout the day,
thus making them suitable for energy harvesting floors
Energy harvesting tiles started off as prototypes in the beginning of the last decade; significant
developments have given them a capability to produce up to 20 watts per hit and about 10 kilowatt-hours
in a week. With the support from environmentalists, these tiles have become a runaway success around
the world.
Some of the leading international players in the footfall energy harvesting floor technology and
technologies used in the products thereof are listed below:
Piezoelectric
 The Facility Architects (UK)
 Innowattech (Israel)
 Soundpower Corporation (Japan)
 Powerleap (US)
 Piezo Power (US)
 Energy Automation (Lebanon)
 Advanced Linear Devices, Inc (US)
Generator
 Sustainable Dance Club (Netherlands) G
 Pavegen Systems Ltd (UK)
 KinergyPower (US)
 The Facility Architects (UK)

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7. IP Perspective
The footfall energy harvesting floor technology came into existence in the mid of 20
th
century. However, it
has received increased attention in the last few years, which is evident from a considerable increase in
the number of patent filings in the piezoelectric sector. The traditional lead zirconate titanate PZT ceramic
is being replaced with organic alternatives such as polyvinylidene difluoride. In addition to creating
piezoelectric systems with enhanced efficiency and temperature performance, companies also lay
emphasis on the flexibility of the materials.
Companies such as Toyota Boshoku Corp, Pavegen, Seratech, Hong Kong Applied Science and
Technology Research Institute Co Ltd are prominent players in energy harvesting floors. Below is a
comparative split of patents/publications owned by the players:
There is a steep rise in the patent filing trend during 2011-2012, due to increasing focus on the research
and innovations in the footfall energy harvesting sector. Companies such as General Electric and East
Japan Railway Company are keen in developing their prototypes. A comparative percentage of details
about the products and prototypes are given below.

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The below table has the list of key players actively involved in both patent filing and manufacturing
products related to footfall energy harvesting floor:
S. No. Key Player Patent title Product Patent document
1. The Facility Architects
Energy harvesting system
using hydraulic circuit
SmartFloor /
Pacesetters
GB2471658A
2. Pavegen Systems Energy harvesting Pavegen WO2011138585A1
3. Sustainable Dance Club
Floor suitable for
generating, converting
and/or storing energy
Energy Floors EP2201247B1
4. Innowattech
Multi-layer piezoelectric
generator
Pedestrian tiles US8278800B2
5
Soundpower
Corporation
Electric apparatus
provided with power
generating function
Power-
Generating Floor
US20120248937A1
6 Kinergypower
Traffic-actuated electrical
generator apparatus
KinergyPad US7629698B2

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8. Conclusion
Though being advantageous in several aspects, such as manufacturing, installation, aesthetics,
maintenance, availability etc, this technology can only contribute to low power applications. It requires
highly-efficient converter mechanism and storage devices and has a less storage lifespan. Besides, the
materials used in manufacturing the devices must be highly durable, as they will be operating throughout
the year. As of today, this technology is in its nascent stages due to the above stated reasons.
Development in the areas of storage and transmission of energy may eliminate all the drawbacks and
make this an effective technology for power harvesting.

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References
http://www2.hull.ac.uk/science/engineering/research/energy,_environ__sustainable/energy_harvesting.as
px
http://health.heraldtribune.com/2013/03/17/the-body-electric-harnessing-human-energy/
http://www.renesas.com/edge_ol/features/09/index.jsp
http://www.greenbusinessguide.co.za/piezoelectric-energy-harvesting-market-to-expand/
http://apps.research.ufl.edu/otl/pdf/marketing/13608.pdf