gst 112.05 ENERGY SOURCES In technology today

General studies on energy sources

1. ENERGY SOURCES, GENERATION AND USES GST 112 HISTORY AND PHYLOSOPHY OF SCIENCE AND TECHNOLOGY ANCHORED BY Dr.( Mrs ) Ezeh Marian Isioma A LECTURER of the Department of Physics Faculty of science Delta State University, Abraka

2. INTRODUCTION ENERGY SOURCES: GENERATION AND USES Chapter five of the GST 112 TEXTBOOK PAGE 43-52 will be divided into the following sub-headings ENERGY IT’S GENERATION SOURCES AND ITS LIMITATIONS AND BENEFITS USEFULNESS TO THE SOCIETY

3. ENERGY It is the ability to do work Work is force applied to move an object through a distance It is measured in Joules(J) or Newton Meter There are two basic forms of energy: potential and kinetic Energy Potential energy is the energy a body possesses at a point Kinetic is the energy a body possess in motion Other forms of energy includes: mechanical, electrical, magnetic and light energy

4. GENERATION Energy is generated from various sources which can be divided into: primary and secondary sources Primary sources involves the energy generated directly from the actual resources available in the earth which are further classified into two groups; renewable and non-renewable energy Secondary sources are derived from the primary sources which are basically used to store energy, transfer and deliver same in a useable form examples are electricity and hydrogen

5. SOURCES NON-RENEWABLE ENERGY SOURCES ARE FOSSIL FUEL AND NUCLEAR ENERGY RENEWABLE ENERGY ARE WIND, SOLAR, BIOMASS, GEOTHERMAL AND HYDROTHERMAL ENERGY DETAILED DISSCUSION AS FOLLOWS:

6. WIND ENERGY It is a type of renewable energy that is defined as the process of producing electricity through the use of wind that occurs naturally in the earth’s atmosphere In order to capture wind energy turbine blades are used A single wind turbine can be used for pumping water, heating houses or for communication purposes WIND energy is clean and does not pollute the environment Storage is impossible and cost of establishing it is very high

7. GEOTHERMAL ENERGY Geothermal energy can be generated by drilling a hole from the surface into the natural occurring convective zone in the earth The earth is divided into different layers namely earth crust, mantle and core This energy are found in abundance in the area of active volcanoes and can easily be obtained where earth crust is thin enough to allow the heat through or in tectonic plate boundaries This heated water which is collected or its steam is used to drive electrical generators to produce electricity

8. GEOTHERMAL ENERGY CONT’D There are three processes of geothermal plants used to harness this hot water or steam into electricity; Dry steam design where the steam from the hot water is passed through a turbine Depressurization process where the hot water is converted into steam in the reservoir In the third process the hot water is passed through a heat exchanger where it is made to heat a second liquid which has a lower boiling point than water Note that the processes end at the turbine from where electricity is generated Electricity generated from this type of energy can be used directly to heat buildings, raise plants in greenhouses, dry our farm products and aid in industrial process

9. GEOTHERMAL ENERGY CONT’D Geothermal energy is usually available throughout the year It is relatively inexpensive when compared to other sources The geothermal well can produce harmful elements such as antimony and arsenic and therefore pollutes the environment and portable water

10. SOLAR ENERGY AS A SOURCE OF ENERGY Solar energy is the radiant energy from the sun The sun is the centre of the universe round which all planets and heavenly bodies Mercury, venus , earth, mars, jupiter , saturn , uranus , neptune and pluto in their order of proximity to the sun, revolve In anticlockwise manner and making one complete revolution at different times Not all the radiation from the sun gets to us since some are trapped in the ozone layers however the amount received is more than enough

11. Solar energy cont’d Energy from the sun also known as solar power have about three aspects of harnessing it; Solar thermal: where a direct sun is used to heat water for bathing, cooking or drying Photovoltaic where solar cells are used as the medium where the sun’s energy is trapped to produce electricity Biomass technology: where dung from agricultural products and animals are collected and stored in a bio-digester and fermentation process occurs without air. After a good quality of retention time, methane gas is produced and stored in cylinders for cooking

12. Solar energy/power cont’d The energy can be stored in batteries inside accessories to be used at night which enhances its usefulness in pumping water, lighting devices, calculators, watches etc Solar energy cannot be harness effectively at all seasons of year especially during rainy season

13. HYDROPOWER ELECTRICITY This is the provision of electricity through water falls usually called DAM which maybe natural or artificial Whether natural or artificial, there must be a huge water basin or possibility of creating one It is low in cost and outstanding The voltages and currents so transmitted are sinusoidal in nature which means it changes with time

14. Hydro-energy cont’d To develop an effective hydro power station a large water basin at appreciable height with active waterfall is sought for or created Active waterfall entails fast flowing water from a considerable height to create the needed force for mechanical energy release Furthermore the waterfalls are concentrated into an intake which serves as water gate to the turbine blades Therefore the greater the height of the waterfall or mass of falling water, the greater the potential energy processed which is further converted into work at the base of the dam where the turbine blades are exposed to the falling water which is used to rotate the turbine

15. Hydrothermal energy cont’d Step up and step down transformers as required are built to enhance the low voltage Hydropower is very reliable, cheap and pollution free It is disadvantageous because it requires large area of land as water basin which can displace many people It is dangerous to fishes and other marine creatures which are likely to fall in the turbine blade and die It is a major hindrance to navigation, exploration and tourism With adequate management of human and material resources hydropower is a realiable choice despite these set backs Examples are Kanji dam in New Bussa .

16. BIOMASS POWER Biomass power means fuel that is produced from organic materials such as cow dung, forest fiber, rice husk, cassava peels and certain waste residue which at combustion will directly produce heat energy Biomass power have also been defined as carbon neutral electricity generated from renewable organic waste

17. Biomass power cont’d It is advantageous due to its availability and abundance in terms of processing, storage and transportation These notwithstanding, its combustion produces air pollutants such as oxides of carbon (CO and CO 2 ), Nitrogen oxides, volatile organic compounds and particulates

18. NUCLEAR POWER Nuclei or particles(projectiles and targets) are capable when in contact to undergo some interactions. These interactions are called nuclear reactions s in mathematics; Projectile nucleus + Target nucleus = Residue nucleus + Emitted particles + Energy The nuclear power reactor or plant is a device in which these nuclear reactions take place and the heat produce is used for the generation of electricity

19. Nuclear power cont’d The advantages includes the emission of CO2 and other greenhouse gases for global warming and production of continuous energy thereby minimizing price volatility of other fuels thereby providing an alternative All the same it is not all rosy as there remains the possibility of nuclear accident and there is also difficulty in managing nuclear waste

20. COAL POWER On combustion of the wood, it releases energy. This energy can used to produce electricity Currently coal-fired power plants is at least 41 percent of global electricity In the processes of generation, the coal is first milled to a fine powder. This powder is then blown into the combustion chamber of a boiler where burning at high temperature occurs resulting in the production of hot gases and some quantity of heat energy which converts the water in the boiler into steam This steam turns the propeller-like blades inside the turbine thus causing the turbine shaft to rotate at high speed thereby producing electricity

21. Coal power cont’d Coal power has been identified as a secure energy source which is sequel to its abundance However there are a number of associated environmental health issues such as Acid mine drainage(ACD), coal dust, water and air pollution, radioactivity, climate change, thermal pollution and landscape alteration Note that remarkable improvements are being made in conventional PCC systems with a view to producing more electricity from less coal so as to minimize pollutant emissions at a global level

22. NATURAL GAS Natural gas is simply fossil fuel in gaseous state Fossil is formed from remains of plants and animals that have decomposed and sipped down the earth over many years on shore or beneath the waters and accumulated to form hydrocarbon or crudes and methane in soil pores. Nigeria is blessed with hydrocarbon Natural gas is usually explored and exploited alongside crude since both are formed from fossil. Natural gas is separated technically from crude when exploited and extracted for use Due to the large amount of natural gas produced gas is flared to handle the surplus, through piped which is against the official procedure of recycling laid down by OPEC. Gas flaring is prohibited because of layer depletion, oxygen consumption, rain acid , bush/farm burning etc

23. Natural gas cont’d Today natural gas is used in propelling variety of industrial machines and for scientific researches involving vacuum deposition chemical reactions, Lathe machine operations and the like In some countries they are channeled to individual homes for cooking and heating at minimal cost Nigeria is thinking in that direction and we shall get there

24. Natural gas cont’d Natural gas is pollution free and relatively cheap. However only few can afford it because of the expensive installation requirements It is Highly inflammable and dangerous when wrongly used It is a non-renewable energy source once used it is gone Moreover it is difficult to preserve and can readily explode. It is recommended the specialist or professionals should handle its processes

25. CONCLUSION With this we draw the curtain and end the class here Take time to study this chapter five thoroughly and prepared for the exams Wishing you all that have registered this course success Hope to see you all in the next level of your course Thanks for your rap attention