[Class Title]
Introduction
Some scholars view energy as an abstract concept that could not be defined by any physical parameters (Lehrman 15). There are those who even admit that they do not know the scientific meaning of energy because it cannot be seen or touched or smelled except that it can only be imagined through its effects. For the same reason, some scholars refrain to define energy to avoid being misconstrued. Engineers, however, need an operational definition for energy in order to apply its concept in many engineering applications such as in mechanics, thermodynamics and electromagnetism. Engineers, especially during the industrial revolution, need a way to compare and measure the capacity and efficiency of mechanical devices, engines and electric motors (Lehrman 16). For the same reason, a functional definition for energy, which refers to it as the capacity or ability of matter to do work, becomes widely adopted (Lehrman 15). This capacity can either be kinetic or moving or potential. Energy is present in all matters. It can also exist in many forms. Among the most common forms of energy are energy produced by motion or kinetic energy, gravitational energy, chemical energy, heat energy, electrical energy, nuclear energy, radiant energy and many other types of energy that are easily observable. Some of these energies are difficult to harness due to technological constraints while others can be readily utilized for practical applications. Thermal and electrical energy, for instance, has many domestic applications so that its use is often encountered in the common household while nuclear energy may seem enigmatic because most people do not usually encounter such energy. One important property of energy is that it could not be destroyed; only transformed from one form into another. However, in the process of transforming one form of energy into another, some of it is lost because of entropy. This is where the work of the engineer comes in; that is, to devise a way that energy can be harnessed and transformed into an energy that can be utilized for many applications and to reduce the entropy of the system during the transformation process in order to create a more efficient way of converting one energy form into another. Over the years, significant progress and improvement have been accomplished for this end through the efforts of brilliant engineers and scientists. The world today benefits from the remarkable efforts of many engineers that have laid down the foundations of energy utilization.
Types of Energy Sources
Non-Renewable Energy. The bulk of energy generation today comes from non-renewable sources. In fact, 85 percent of the world’s energy produced is obtained through non-renewable fossil fuel . Fossil fuel and natural gas are the most common sources of non-renewable energy. These fuel resources are extracted underground and processed so that they can be utilized as fuel for devices that can convert their chemical properties into other forms of energy such as mechanical and electrical energy.
Renewable Energy. Renewable or green energy refers to those energy sources that cannot be depleted or can be replenished naturally over time . Among the most common renewable energy are solar, hydro, wind and geothermal energy. Environmentalists promote the utilization of renewable energy, primarily because they cause less pollution as compared to the burning of fossil fuel. But despite the campaign to increase the utilization of renewable energy, its use is still low compared to non-renewable energy.
Nuclear Energy Utilization. Nuclear energy is a special case of non-renewable energy. What is unique about this energy source is that it releases an enormous amount of energy through the breaking or fusing of atomic particles. The enormous heat produced through this process can be utilized to create a constant supply of high-pressure steam, which in turn is converted to mechanical and electrical energy. A kilogram of uranium can produce 20,000 times the energy produced by a kilogram of fossil fuel, which makes nuclear energy a more economical and efficient energy source . The problem with nuclear energy, however, is in the magnitude of its environmental and health impacts in case it malfunctions or is damaged through man-made or natural means.
Common Ways on How Engineers Harness Energy Sources
Most often, engineers use mechanical devices in order to harness the kinetic and potential energy of renewable and non-renewable sources. From simple mechanical devices, engineers have developed more sophisticated ways on how to harness energy from various sources. The creation of ingenious, muscle-powered, mechanical devices such as the lever and the pulley, for instance, allowed people to magnify their body energy as well as the energy of their work animals in order to lift heavy objects or do tasks that would have been otherwise difficult or impossible to accomplish through manual labor alone. The expending of biomass or the “biological material from living, or recently living, organisms” in order to produce the energy required to operate these devices (Sources and Uses of Energy: A brief overview 1). From this primitive method of harnessing biomass to create mechanical energy, engineers realize that burning organic matters releases huge amounts of energy that can be converted to mechanical work. The steam engine is the first to utilize this principle and with the discovery of fossil fuel, such principle was utilized extensively, especially during the initial stages of the industrial revolution. The English military engineer, Thomas Savery, for instance, was the first to invent a steam-powered engine, which he used to pump water . Savery’s engine design, however, was too crude for practical application and has a high risk of exploding and so it was quickly abandoned. Another English inventor by the name of Thomas Newcomen, improved Savery’s design by using steam and atmospheric pressure to move a piston through a vertical cylinder. The modern steam engine, however, is attributed to the work of the Scottish mechanical engineer, James Watt. Watt improved the work of Newcomen by adding a separate condenser chamber, which can be cooled without cooling the steam chamber. This design eliminated the need to cool-off the steam cylinder, thereby providing an efficient and steady supply of steam. Watt’s improvement of the steam engine was groundbreaking that it was one of the major factors that helped bring about the industrial revolution.
One of the greatest improvement in the utilization of fossil fuel as a source of energy is the invention of internal combustion engines that used diesel and gasoline as fuels. The principle behind the internal combustion engine is to convert fossil fuel to mechanical energy through rapid burning or combustion. The rapid and successive burning of fossil fuel creates an explosion inside the machine that triggers the piston to move back and forth, thereby converting the chemical energy of the fuel into mechanical work. Attempts to create an internal combustion engine can be traced back as early as the 1680s when the Dutch Physicist, Christian Huygens, designed an engine that uses gun powder as its fuel (Ratiu 146). His design, however, was never built. The first practical combustion engine was built by the Belgian engineer, Jean Joseph Étienne Lenoir, who used an electricity to ignite coal gas (Ratiu 146). Lenoir’s engine was the first to travel over a distance of 50 miles (Ratiu 146). Nikolaus August Otto, a German engineer, further improved the efficiency of internal combustion engines by introducing a design that uses four strokes of the piston to complete a power cycle (Ratiu 146). Otto’s design became the forerunner of most internal combustion engines. Another important development is the creation of the diesel engine by the German engineer, Rudolf Diesel in 1893 (Fernando 5). The diesel engine also operates in a four-stroke cycle like the Otto engine only that it uses heat and compression to ignite the fuel, whereas Otto engines rely on electrical ignition to ignite its fuel or gas.
There are many other devices that engineers have helped design for the purpose of harnessing energy. In fact, the list would be exhaustive, if all of the energy harnessing devices are considered. Among the most common are turbines, dynamos, photovoltaic cells and batteries. Turbines are mechanical devices that utilize the energy of moving fluids such as steam, moving water and wind and transform them into mechanical or electrical energy. A dynamo, on the other hand, is a device that converts mechanical energy to electrical energy. Dynamos are often attached to the turbines or engines in order to convert the mechanical energy generated by these machines into electrical energy. Solar cells or photovoltaic cells utilize the energy of the sun and converts them directly to electrical energy. Batteries are chemical devices that can store potential energy. Among the first batteries are lead-acid batteries, so called because it uses acid as its electrolyte and lead as its electrode. These batteries, however, corrode easily and have a short life. In the early 1900s, the American inventor, Thomas Edison significantly improved the capacity of batteries by using alkaline.
Conclusion
There are many ways on how engineers harness energy for practical use. The most common way is to convert chemical or thermal energy into mechanical energy. Energy can also be converted from mechanical to electrical or from chemical to electrical as in the case of solar and photovoltaic cells. Whatever the processes involved, engineers have an integral part in the utilization of energy sources. From an engineering perspective, the central idea in terms of energy utilization is to create a system or device that would harness the energy from various sources and transform them into a form of energy that can be utilized for practical applications. From the most basic to the most complicated, engineers develop and improved these processes and devices over time so that they can be used to efficiently convert energy sources for practical application.
Works Cited
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