Conventional Source of Energy
Conventional Source of Energy:
Energy affects every part and every field of our life. We need energy to do all sorts of physical and physiological activities like moving writing, running, cooking, thinking or doing any work. We need energy for transportation, communication, lighting, industries and agriculture. We also need energy to extract minerals from ores and to manufacture fertilizers, pesticides and all other products. We need energy for space travel and all scientific activities. Thus, we see there is hardly any aspect of life which we can think of that does not require energy. In fact, energy use is an indication of the degree of development. Some 99 percent of the energy used to heat our earth and all our buildings comes directly from sun. Without this direct input of solar energy our earth's temperature would have been 240°C and life would just not have been possible. The 99% of the energy coming from sun to the earth is natural and not sold in the market. The remaining one percent is the commercial energy used by people in different forms like fuel wood, coal, oil, dung, electricity etc. The energy sources can be broadly categorized into renewable and non-renewable resources. While renewable resources like biomass energy, solar energy, tidal energy, wind energy, Hydel Power Energy etc. can be regenerated, the non-renewable energy resources like coal, petroleum and natural gas are fossil fuels which took millions of years to be formed and cannot be renewed during our life span.
Thermal-electric power plants, hydro-electric power plants, and nuclear power plants supply most of the electrical energy used in Ontario. These three methods of producing electricity are oft en referred to as conventional energy sources. This means that they are the more traditional or more commonly used sources of electrical energy. Why are these conventional energy sources so widely used? What advantages and disadvantages do they have compared to other energy sources? Think about these questions in this section.
Electrical energy is produced in hydro-electric power plants from the energy stored in water behind a dam (Figure 1). As this water falls through the penstock, the water’s energy of motion spins the turbines. The spinning turbines turn the electrical generator that transforms the water’s mechanical energy into electrical energy. Hydro-electricity is a renewable energy resource. The water above the dam is replaced continually by natural processes (rain). We can obtain energy from a hydro-electric power plant almost indefinitely. Hydro-electricity is often thought of as a “clean energy” source because hydro-electric power plants produce little to no pollution. This does not mean that they have no impact on the environment. The construction of a major hydro dam oft en results in the flooding of a large area of land. The dam also stops fish and other animals from moving up and down the river. Water in reservoirs above hydro-electric power plants may also get warmer and become lower in oxygen content than free-flowing river water. This also negatively affects the water’s ecosystem. Another disadvantage of hydro-electricity is that the dams can only be built on certain sites. For example, although Ontario has many rivers and streams, there are few suitable sites for more large hydroelectric power plants.