It is sometimes of benefit to
look back in time at the development of our energy systems to gain
some perspective on how well we have progressed, or not, and perhaps
gain some insight as to where we need to concentrate our efforts in
research and development.
Where
Have We Come From?
During the first half of the
18th
century, apart from animal power, the energy available to turn a
shaft to do work came from a water wheel, which is power from gravity
using a large amount of mass in liquid form, or, from a wind powered
wheel which is solar radiation moving a large amount of mass in
gaseous form. Both require special site conditions and are ultimately
powered by the sun.
The Industrial Revolution,
beginning in about 1750, saw a change which allowed the power to turn
a shaft become more portable, in the form of the Watt and Boulton
steam engine, which was commercially available from 1776. The fuel
for the steam engine was portable, in the form of solar radiation
energy chemically bound up in hydro-carbon compounds such as wood and
coal. As the steam engine was modified and improved, the engine
itself became more portable and was utilized in mobile devices such
as locomotives, ships and tractors. The steam engine and its
associated technology such as the Stirling engine can be classified
as external combustion engines. They have an efficiency of around
20%, which means that about 20% of the energy from the fuel input is
converted to mechanical energy to do work, and the other 80% is lost
to the environment as heat and friction.
About a century after the steam
engine came the gasoline and diesel internal combustion engines.
These were generally lighter and more portable and opened the way for
the automobile, aeroplane and many other devices which added to our
comfort and convenience. Their fuel is of a more concentrated and
energetic source of hydro-carbon compounds and spawned the huge oil
industry, which now supports much of our energy needs. The internal
combustion engine is about 50% efficient at best, about half of the
energy from the fuel being lost to the environment.
Both the external and internal
combustion engines are ultimately powered by their fuels which are
actually only fossilized material whose energy comes from solar
radiation. They are both heat engines and can never be 100%
efficient, as is evident from the Carnot cycle in thermodynamics.
During the same period which saw
the development of the external and internal combustion engines,
physicists such as Lorenz, Maxwell, Faraday, Thomson and Tesla were
developing the theory and practical uses of electro-magnetism.
Faraday invented the first electric motor, the direct current (dc)
homo-polar motor, and it was much later that Tesla invented the
alternating current (ac) induction motor. Modern electric motors have
an efficiency in excess of 80%. They are not subject to the Carnot
cycle of thermodynamics, and can theoretically have an efficiency of
100%. The electric dynamo was developed along with the electric
motor, it is almost an identical machine. At the beginning of the
20th
century the more technically advanced nations developed a system of
distribution of electrical energy so that it could be commercially
exploited for profit by providing the population with electricity
within their homes and businesses. The distribution systems are based
on ac power for technical reasons and have not much changed over the
20th
century, except to become larger with increasing population, and more
challenging to manage.
Electro-magnetic energy is
ideally suited to our needs as it is concentrated, easy to distribute
and is safe. It is easily converted to another form such as heat or
mechanical and can be manipulated for use in complex electronic
equipment. The electrical and electronics industries are amongst the
largest on Earth, and continue to develop into better and more
complex uses.
What
has Changed?
What has not
changed is how we generate electro-magnetic energy. We are still
using steam engines! They are now called steam turbines, but are
essentially the same machine. Most are fueled from coal, as they were
in 1776. Some are fueled from gas or oil and the nuclear power plants
still heat water for the steam engine to turn the dynamo. Our
hydro-electric power stations still use gravity powered water as in
1750. Our wind turbines work the same as in 1750 except the shaft
they turn is connected to a dynamo. They are both more efficient, bur
essentially the same. The same remark applies to the steam turbines
and internal combustion engines. Geothermal plants still heat water
to power a steam engine and dynamo, although the fuel is free.
What is
new is the conversion of solar radiation directly into electricity
using the photo-electric effect pioneered by Einstein, for which he
was awarded a Nobel Prize. Solar radiation is of the same
concentration, or intensity, as electro-magnetic energy and so does
not require huge masses impelled by the weaker gravitational field,
or endless mechanical energy via a dynamo. The drawback is that solar
radiation is spread over a large area on Earth, so that solar cells
also need to cover large areas to trap the radiation and convert it
to electrical energy. The expense of creating a large enough area of
solar cells to power the planet both day and night is prohibitive at
present.
The transmission of electricity
is rapidly becoming a weak link in our energy system as it grows. We
need a new paradigm here, as well as a way to transmit electrical
energy to a mobile user.
Solar
Electricity on a Grand Scale
It would be ideal to have an
area about half the size of the planet generating electricity
continuously from solar radiation so that there would be no need to
store it during hours of darkness, and a wireless distribution
system, or, alternatively each consumer with wireless access to the
source. Surprisingly, those options are probably within our reach.
The sun continuously creates an electrically positive pole in the
ionosphere. The negative pole is the Earth itself. The voltage
between the two poles is of the order of 100,000 volts. Evidence of
this is sometimes seen as the auroras or as lightning from high storm
cloud. The voltage is there day and night right around the Earth. The
question is how to bring that positive charge down to ground level
where it can be rectified and manipulated to suit our present
distribution network or any new network we may devise. The other
challenge is the wireless transmission of energy. This has also been
pioneered by Einstein's contemporary physicist Nikola Tesla. In the
very late 19th
century at Colorado Springs in the USA, Tesla succeeded in
transmitting about 5 kw of electrical energy from a generator to a
bank of light bulbs at a distance of 16 km through the Earth without
wires. The experiment is said to have worked by utilizing the
frequency compatible with the Earth as conductor. Tesla said that
frequency was the key to the solution of many electrical challenges.
As the inventor of the ac electrical system he should be taken
seriously. This work needs further study and experimentation.
From
Wikipedia
'Tesla's diary
contains explanations of his experiments concerning the ionosphere
and the ground's telluric
currents
via transverse
waves
and longitudinal waves.[115]
He researched ways to transmit energy wirelessly over long distances
(via transverse waves, to a lesser extent, and, more readily,
longitudinal waves). He transmitted extremely
low frequencies
through the ground as well as between the earth's surface and the
Kennelly–Heaviside
layer.
Tesla received U.S.
Patent 645,576
for wireless transceivers that developed standing waves by this
method. In his experiments, he made mathematical calculations and
computations based on his experiments and discovered that the
resonant
frequency
of the earth was approximately 8 hertz (Hz)[116]
(later confirmed by researchers in the 1950s—named the Schumann
resonance).[117]
Tesla sent electrostatic forces through natural media across a
conductor situated in the changing magnetic
flux
and transferred electrical energy to a wireless receiver.' Wikipedia.
Earthbound
Impediments
Vested interests are powerful
impediments to new technology, for example the oil, gas and coal
industries lobby against change, as do their bankers,
employees, governments and other stakeholders. R and D funding would
need to be sourced perhaps from the electronics and IT sectors who
may have the funds and motivation to develop (and control) a new source of energy.
The science may not be all that difficult.