The World Demand for Power

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Physics Research Report

The World Demand for Power

Summary

The world's demand for power is currently increasing at an alarming rate. Essentially, this demand is currently being met by a small number of energy sources. These include:

* Fossil Fuels

* Alternative Sources (Hydroelectric and Solar)

* Nuclear Power (Fission)

Nuclear fusion power is also in development and will possibly become one of the main sources once fully developed.

This report looks some of the basic Physics currently behind these energy sources and how further advances may be brought about by understanding the Physics of the process.

Introduction and Fossil fuels role

According to a study undertaken by the World Energy Council, by 2020, Western European oil and gas reserves will have declined to a point at which only Norway is expected to have significant reserves of natural gas and Western Europe may well enter a phase of declining oil production and rising oil import dependency. In 25 years time, Europe's dependence on the external supply of conventional fuels is likely to have increased from the current level of around 50% to around 70%.

There are a number of other factors that must be taken into consideration. In 1990 some 75% of the world's population (those in the developing countries) were responsible for only 33% of the world's energy consumption; by the year 2020 that 75% is likely to have risen to 85% and the energy consumption to around 55% (see chart). Thus there will be greater competition for the fuel resources available

The means we have currently of powering our needs, with coal, oil or gas are generally accepted by the masses. However their reputations and standing have been somewhat damaged in recent times with heightened awareness of their environmental hazards. Yet their ability to achieve their fundamental objective, to produce power is unquestionable. Despite the implication of damaging the planet, Governments generally across the world are also in support of fossil fuels and refuse currently to pursue any of the new methods with any seriousness. Despite this lack of commitment the fact is oil, coal and gas take centuries to produce whilst we are using them at a ridiculous rate. The end of the 'tank', which governments seem to fail to accept exists, must therefore be quickly approaching. Recent prediction indicate we have approximately 40 years, continuing at the current rate of power use, until the oil we have discovered dries up. Gas also has an estimated 40 years whilst coal resources are much greater and are expected to last for another century. Coal has become somewhat redundant though with it proving must dangerous to the atmosphere. The fossil fuel that currently provides the Earth with the majority of its energy is oil, contributing 60%. Due to this heavy reliance on the fossil fuel, which has emerged the most suitable for our needs, oil is great demand. The entire Earth, land and sea, has been searched for oil 'reservoirs' and once found as much oil as possible is extracted.

Oil Extraction

As we have said 'the end of the tank' is approaching. One interesting application of Physics is now being used to defer this time. This occurs in the process of oil extraction to actually extract more from existing resources.

Once located and 'drilled' the reservoirs of oil would traditionally rely upon the pressure naturally created by the gas present under the ground to force it up. As the oil was extracted the pressure in the reservoir that forced the material to the surface would gradually decline.

Eventually the pressure will decline so much that the remaining oil will not migrate through the porous rock to the well. When this point is reached, less than one-third of the oil in an oil field will have been extracted. The equating of the pressure acting on the oil 'pocket' and the outward acting pressure from within the 'pocket' cause this drop in pressure. The pressure acting outwards is caused by a lot of molecules being kept closely together in a confined space. Pressure is calculated using the equation:

p = 1/3 Nmv2/ V

Where p is pressure, N is number of molecules, m is momentum, v2 is the average of the velocities squared and V is the volume in which the molecules are restricted.

Using this equation in our situation the only variable we have on the right hand side is the volume. Once a hole has penetrated the oil reservoir the restricted volume is no longer comparatively small but has become an infinite space. This huge increase in V, the denominator in our equation reduces p to almost zero, which is why the natural pressure within the 'pocket cant be relied upon. Part of the remaining oil can be recovered by using gas or water to push the oil to the well, but even then, one-fourth to one-half the oil is usually left in the reservoir. In an effort to extract this remaining oil, oil companies are now beginning to use chemicals to push the oil to the well, or to use fire or steam in the reservoir to make the oil flow easier. Implementing the use of fire causes the temperature to rise. Raising the temperature will have a beneficial effect due to what is shown in the following equation that links pressure and temperature.

p = NkT / V

Where p is the pressure, N the number of molecules and V the volume in which the molecules are held. This time however T, temperature and k, the Boltzmann constant are introduced.
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In this instance of using fire to raise the temperature in the pocket it has the effect on the equation of increasing T. T is the denominator on the right hand side of the equation and with the other variables remaining constant p also increases. This greater pressure aids the process of extraction.

The modern methods of Power

With the help of physics, modern scientists can produce more energy with a tiny radioactive pellet than they can with several tons of coal, gas, or oil.

Since the late 1930's it has been hoped that science ...

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