Energy technology is concerned with developing systems capable of producing, transporting and delivering energy in a way that is safe, economical and, increasingly, environmentally-friendly. Generally speaking, it is a field of many overlapping disciplines. Hard sciences, such as physics and chemistry, are crucial to understanding where energy may be available. Engineering disciplines are required to design the systems that harness energy. Finally, environmental science is used to measure the impact of energy technology on the natural world.
Some of the first energy technologies were designed to extract energy from fire. Burning fuel, which could be wood, coal or oil, produces heat—a form of energy. Using this heat to boil water will create steam. In a steam engine, this steam is used to push a piston and turn a crankshaft, which is a form of mechanical energy. This rotational motion can be harnessed to power machines in a factory or to turn a propeller on a ship.
In fact, most applications of energy technology for transportation purposes use this same basic process. Steam ships revolutionized shipping methods during the First Industrial Revolution and later began to replace sail-powered vessels as the primary ships of war. These steam ships used coal as fuel. During the Second Industrial Revolution, transportation energy technology began to utilize oil as the primary fuel. Oil-based internal combustion engines are used in every country of the world for transportation applications.
In 1881, electricity was first generated at a central station and delivered to other locations. Electricity is the flow of electrically-charged particles; these particles can carry energy with them in a way that is analogous to water pressure. Therefore, transporting energy to other locations is the function of electricity.
Any source of energy can be converted into electricity using energy technology. Sources of electricity in the United States include coal, natural gas, and nuclear power. The sources of electricity generation and fuels for transport often differ because of the different requirements for each application. Electricity power plants must be very efficient in generating the most electricity possible. Transportation energy systems, on the other hand, can get away with less fuel efficiency, because they also need to be small and light enough to fit into vehicles.
A growing concern is the development of alternative energy sources. Coal, oil and natural gas are all non-renewable energy sources, meaning that they exist in finite quantities in Earth and could one day be used up. Burning coal and oil have negative environmental effects, which are also a growing concern. Energy technology is being pursued to develop clean, efficient and renewable sources of energy for both electricity and transportation applications.