Transcript Senior Design Project Poster Template

Possibility of Energy Scavenging from the Earth's Electric Field
Eric Cartman, Larry Howard, Moe Howard, Curly Howard
Department of Engineering and Physics, University of Central Oklahoma, Edmond, OK 73034
Abstract
It has long been known that the earth has an ambient
electric field of approximately 100 V/m directed vertically
downward. The possibility of energy scavenging and
harvesting this ambient electric field is examined. JouleThief type circuits are used to examine this possibility.
Overview
Energy Harvesting is the process of capturing minute
amounts of energy from naturally-occurring energy
sources, accumulating them and storing them for later
use. Energy-harvesting devices efficiently and effectively
capture, accumulate, store, condition and manage this
energy and supply it in a form that can be used to
perform a helpful task.
Why Energy Harvesting?
Advanced technical developments have increased the
efficiency of devices in capturing trace amounts of
energy from the environment and transforming them into
electrical energy. In addition, advancements in
microprocessor technology have increased power
efficiency, effectively reducing power consumption
requirements. In combination, these developments have
sparked interest in the scientific and engineering
community to develop more and more applications that
utilize energy harvesting for power.
Energy harvesting from a natural source where a remote
application is deployed, and where such natural energy
source is essentially inexhaustible, is an increasingly
attractive alternative to inconvenient wall plugs and
costly batteries. This essentially free energy source,
when designed and installed properly, is available
maintenance-free and is now available throughout the
lifetime of the application. Such systems can be more
reliable than wall plugs or batteries.
In addition, energy harvesting can be used as an
alternative energy source to supplement a primary
power source and to enhance the reliability of the overall
system and prevent power interruptions.
Background
The earth’s surface carries a
negative charge and the lower
atmosphere has a positive
charge resulting in a net
downward electric field of
approximately 100 – 200
volts/meter.
McKenzie (1956) gives an excellent short account of this
electric field and its variation and Feynman (1974) gives
a vivid description of the basic physics.
Tesla in a 1901 in a pair of U.S.
patents, Apparatus For The
Utilization of Radiant Energy and
Method Of Utilizing of Radiant
Energy describes an apparatus
for scavenging what he terms
“radiant energy” from the natural
environment.
Tesla idea outlined in these patents was very simple:
Referring to the diagram above, stick a metal plate, P,
as an antenna in the air, the higher and the larger the
plate area the better, and wire it to one side of a
capacitor, the other going to a good earth ground, F, and
the potential difference will then charge the capacitor, C.
Connect across the capacitor a switching device, d-R, so
that it can be discharged at rhythmic intervals, and you
have an oscillating electric output. There is no record of
Tesla ever having built the device, but in view of its
simplicity and the resources he had available at the time,
it would be surprising if he did not test it. Tesla believed
that radiation of some sort from the sun or some other
source impinged on the plate and charged the system.
Hermann Plauson , the director of the "Otto Traun
Research Laboratories" in Hamburg, Germany during
the 1920s, built on Tesla's idea with a patent that
describe methods to convert alternating radiant static
electricity into rectified continuous current pulses. He
claims to have made numerous measurement and
reported some experimental results in his book
"Production and Utilization of the Atmospheric
Electricity" (Gr., Gewinnung und Verwertung der
Atmospharischen Elektrizitat).
Experimental Setup
Future Development
In Fall 2008, a student research project was initiated to
investigate the claims of the Tesla and Plauson patents
and if verified to collect data in an attempt to identify the
source of the ambient energy.
Work is planned for Summer 2009 to investigate the
effect of receiving plates with different areas and made
from different materials. In addition, the effect of plate
orientation and height will be studied. This will hopefully
give some clues as to the origin of the potential
difference.
The basic circuit tested
is shown at right. The
insulated antenna wire
was connected to a 24” x
36” copper plate
insulated by a laminated
coating.
In March 2009, a construction of the apparatus was
completed to investigate the claims of the Tesla and
Plauson patents and if verified to collect data in an
attempt to identify the source of the ambient energy.
The circuit shown above was constructed and the
voltage across the capacitor bank was monitored for
approximately three days after a two day period to allow
the charge to build up. The results are shown in Figure
1 below.
A large capacity bank of capacitors will be developed to
hopefully store energy and determine if the system has
any practical viability as an energy source.
The results of the ongoing project will be reported at
future date.
References
R.P. Feynman, et a1., The Feynman Lectures on
Physics v01 2 (Addison Wesley, New York,1974)
Chapter 9.
H. Plauson - "Conversion of atmospheric electric
energy" U.S. Patent 1,540,998 (
A.E.E. McKenzie, A Second Course of Electricity
(Cambridge University Press, Cambridge, 1956)
Chapter 3.
N. Tesla, Apparatus For The Utilization of Radiant
Energy, US Patent 685,957 (1901).
N. Tesla, Method of Utilizing Radiant Energy , US
Patent 685,958 (1901).
Results
The voltages and charges obtained were low but may
result from leakages and less than optimal grounding of
components. There is reason to believe from the
preliminary tests that sufficient power could be harvested
using this or similar device to run low power device
electronics. We were able to power a LED using JouleThief circuit using the described antenna system to
harvest the required energy. There are reasons to
believe the system could be scaled up.
Contact Information
W. J. Wilson
Department of Engineering and Physics
Howell Hall 221H
University of Central Oklahoma
100 N. University Drive
Edmond, OK 73034
USA
Tel: 405.974.5470
Fax: 405.974.3812
Web: www.physics.uco.edu
Email: [email protected]