Unleashing the power of lightning v1.6

Unleashing The
Power Of Lightning
“…In Quest Of Energy For Humanity…”

Rohan Reddy Melachervu
…In Pursuit of Energy for Humanity…

Class 6, Section D
DPS, Hyderabad

Delhi Public School, Hyderabad
© Rohan Reddy Melachervu. All rights reserved.

Contents
• Why Care About Lightning?
• The Sights and Sounds of Lightning
• What is Lightning?
• Lightning Formation
• Frequency and Distribution
• Lightning Types
• Physical Effects
• Power of Lightning
• Unleashing Lightning Power
• Harvesting Lightning
• Anatomy of Energy Transformation
• Lightning Harvesting Challenges
• Harnessing Lightning Power
• Living in Lightning Alley

Unleashing The Power of Lightning “…In Pursuit of Energy for Humanity…” © Rohan Reddy Melachervu. All rights reserved.

Why Care About Lightning?

There are approximately 2,000 thunderstorms at any given moment
worldwide

Lightning strikes 40–50 times a second worldwide, for a total of nearly
1.4 billion flashes per year

About 95 people die from lightning yearly in the U.S.

A moderate thunderstorm generates several hundred megawatts of
electrical power


The Sights and Sounds of Lightning (1/3)
Thunder Storm

4-second video of a lightning strike, Island in the Sky, Canyonlands National Park, Utah, United States



High speed photography showing different parts of a lightning Flash during the Discharge process as
seen in Toulouse, France



View from an Aero plane


What is Lightning? (1/2)
 A massive electrostatic discharge caused by
unbalanced electric charges in the atmosphere
accompanied by the loud sound of thunder
 It could be:
 Cloud to itself – Intra-Cloud
 Cloud to a cloud – Inter-Cloud
 Cloud to ground – CG
 Ground to cloud - GC
 Caused by circulation of warm moisture-filled air
through electric fields in which ice or water particles
accumulate charge a la Van de Graaff generator
 Usually produced by cumulonimbus clouds which are
at 5–6 km above the ground
 Lightning has been observed within the atmospheres
of other planets, such as Venus, Jupiter and Saturn


What is Lightning? (2/2)
 A typical cloud to ground lightning strike is over 5 km long
 A typical thunderstorm has three or more strikes per minute at its peak
 The science of lightning is called fulminology and the fear of lightning is called
astraphobia


Formation (1/2)
Hypothesis
 Cloud particle collision hypothesis
 According to this cloud particle charging hypothesis, charges are
separated when ice crystals rebound off graupel - a soft ice-water
mixture. Charge separation appears to require strong updrafts which
carry water droplets upward, supercooling them to between -10 and -
40 °C (14 and -40 °F). These water droplets collide with ice crystals to
form graupel. Collisions between ice crystals and graupel pellets
usually result in positive charge being transferred to the ice
crystals, and negative charge to the graupel.
 Updrafts drive the less heavy ice crystals upwards, causing the cloud
top to accumulate increasing positive charge. Gravity causes the
heavier negatively charged graupel to fall toward the middle and lower
portions of the cloud, building up an increasing negative charge.
Charge separation and accumulation continue until the electrical
potential becomes sufficient to initiate a lightning discharge, which
occurs when the distribution of positive and negative charges forms a
sufficiently strong/high electric field.
 Polarization mechanism hypothesis
 Falling droplets of ice and rain become electrically polarized as they
fall through the earth's magnetic field;
 Colliding/rebounding cloud particles become oppositely charged.


Formation (2/2)
 When the local electric field exceeds the dielectric strength of damp air (about 3
million volts per meter), electrical discharge results in a strike, often followed by
commensurate discharges branching from the same path
 Even assuming an electric field has been established, the mechanism by which the
lightning discharge begins is not well known


Frequency and Distribution
 Cloud-to-ground (CG) lightning accounts for 25% of
lightning globally
 The base of the negative region in a cloud is typically
at the elevation where freezing occurs
 The closer this region is to the ground, the more likely
cloud-to-ground strikes are
 In the tropics, where the freeze zone is higher, 10% of
lightning is CG
 At the latitude of Norway (60° lat.) where the freezing
elevation is lower, 50% of lightning is CG
 Lightning is not distributed evenly around the planet
 About 70% of lightning occurs on land in the
tropics, where most thunderstorms occur
 The place where lightning occurs most often is near
the small village of Kifuka in the mountains of eastern
Democratic Republic of the Congo - where the
elevation is around 975 metres - receives 158
lightning strikes per 1 square kilometer (0.39 sq mi) a
year.


Cloud-To-Ground Lightning (1/3)

 As a thundercloud moves, an equal and
opposite electric charge of the base of the
thundercloud is induced on the Earth's
surface below the cloud’s shadow
 The above effects creates and electric field
in the air between the two
 This electric field varies in relation to the
strength of the surface charge on the base
of the thundercloud.
 Neutralization of the surface occurs in
milli seconds where the positive charges
race inward towards the strike
termination
 This rapid change, referred to as step Illustration: A negative leader -
potential, is often responsible for more blue meeting a positive streamer
injury or deaths than the strike itself - red and the return stroke


Downward Leader Formation
 A channel of ionized air, starts from a negatively
charged region of mixed water and ice in the
thundercloud
 Ionized channels are referred to as leaders
 These leaders are conductors for lighting
discharge as they travel outward and are invisible
to the naked eye
 The positively and negatively charged leaders
proceed in opposite directions, positive upwards
within the cloud, the negative towards the earth
 Both ionic channels, proceed in their respective
directions, in a number of successive
High speed photography showing
spurts, similar to two kids hopping randomly in
different parts of a lightning Flash during
the Discharge process as seen opposite directions
in Toulouse, France  It may split into two different directions, called
branches in a fashion similar to a tree, resulting in
multiple leaders
 This process results in something resembling
stairs and is referred to as "stepped leader(s)"
once visible during discharge

Upward Streamers
 When a stepped leader approaches the ground, the
presence of opposite charges on the ground enhances the
strength of the electric field
 The electric field is strongest on grounded objects whose
tops are closest to the base of the thundercloud –
trees, tall buildings
 If the electric field is strong enough, a positively charged
ionic channel, called a positive or upward streamer, can
develop from these points – first theorized by Heinz
Kasemir
 As negatively charged leaders approach, grounded objects
already experiencing corona discharge exceed a threshold
and form upward streamers
 Once any downward leader connects to any upward leader
available, a process referred to as "attachment", a circuit is
formed and discharge may occur
 The ionized channel established between the cloud and
A lightning flash terminates & discharge occurs ground becomes a path of least resistance allowing current
on a tree while an un-attached streamer is to propagate from Earth back up the leader into the cloud
visible on the earth surface projection to the which is called return stroke and it is the
left.
most luminous and noticeable part of the lightning
discharge

Other Types of Lightning

Cloud-To-Ground Cloud-To-Cloud
Multiple paths of cloud-to-cloud
lightning, Swifts Creek, Australia


Thunder
Physical Effects of Lightning

Energy Radiation

Induced Magnetism


Thunder
• The gaseous molecules in this channel undergo a rapid
increase in pressure and thus expand outward from the
lightning creating a shock wave audible as thunder
• Lightning discharge super heats the discharge channel
to plasma temperatures in a short duration
• Light travels at about 300,000,000 m/s and sound
travels through air at about 340 m/s
• A lightning flash preceding its thunder by five seconds
would be about one mile (1.6 km) (5x340 m) distant
• A flash preceding thunder by three seconds is about
one kilometer (0.62 mi) (3x340 m) distant



Energy Radiation
• The cause of the X-ray emissions is still
a matter for research
• Researchers at the New Mexico
Institute of Mining and Technology
detected X-ray emissions from an
induced lightning strike along a wire
trailed behind a rocket shot into a
storm cloud
• A number of observations by space-
based telescopes have revealed even
higher energy gamma ray emissions



Induced Magnetism
• The intense currents of a lightning discharge create a
fleeting but very strong magnetic field
• In general, the movement of electrical charges produces
a magnetic field
• If lightning current path passes through rock, soil, or
metal these material can become permanently
magnetized
• This effect is known as lightning-induced remanent
magnetism, or LIRM


The Power of Lightning

One strike has enough energy to light 150,000,000 light
bulbs

One storm can discharge enough energy to supply the
entire U.S. with electricity for 20 minutes

A single thunderstorm can release 470 million liters of
water

A typical lightning bolt may transfer 1020 electrons in a
fraction of a second, developing a peak current of up to
1000 kiloamperes


Unleashing Lightning Power

• Approximately 5 • Hence - extremely
billion joules of Energy high electrical power
is released during a • This energy is is involved
typical lightning concentrated in a
small location and is
transacted during an
extremely short period
of time – milliseconds


Harvesting Lightning

Since 1980s, there have been several attempts to
investigate the possibility of harvesting energy from
lightning

• The energy contained in lightning
be used to generate hydrogen from
water
The Proposals:
• Or to harness the energy from
rapid heating of water due to
lightning

Lightning electricity technically does not need to be
generated, only transformed into a useful quality


Anatomy of Energy Transformation


Harvesting Lightning Energy
Challenges
• The ever-changing energy involved in each lightning bolt

• Lightning is sporadic, therefore energy would have to be collected and
stored

• Difficult to convert high-voltage electrical power to the lower-voltage power
that can be stored

• Impossibility of predicting when and where thunderstorms will occur

• A technology capable of harvesting lightning energy would need to be able
to rapidly capture the high power involved in a lightning bolt


Harnessing Lightning Power
Massive Electrolysis Producing Hydrogen and Oxygen
From Water


Economics of Energy Generation


Living In Lightning Alley
Lightning Strike Music Video


Thank You
Unleashing The
Power of Lightning
“…In Pursuit of Energy for Humanity…”

Rohan Reddy Melachervu
…In Quest of Energy for Humanity…

Delhi Public School, Hyderabad

©Rohan Reddy Melachervu. All rights reserved.

References

1. http://www.britannica.com/blogs/2012/01/what-causes-lightning/
2. http://www.hk-phy.org/iq/lightning/lightning_e.html
3. http://www.lightandlightning.com/what-is-lightning/
4. http://en.wikipedia.org/wiki/Harvesting_lightning_energy
5. http://www.redorbit.com/news/space/1821830/are_tgfs_hazardous_to_air_travel
ers/
6. http://www-star.stanford.edu/~vlf/palmer/palmer.htm
7. http://wattsupwiththat.com/2009/11/08/antimatter-signature-spotted-in-
earths-lightning/
8. http://faculty.icc.edu/easc111lab/labs/labi/prelab_i.html
9. http://peswiki.com/energy/Directory:Lightning_Power


Unleashing the power of lightning v1.6

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