Energy and Engines - How far have we really Progressed ? An article for non-Physicists.

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 18^th 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 20^th 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 20^th 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 19^th 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.