CEE54 EEM Unit - 2.pptx

How to be useless

1. unit-ii Energy Requirements and Utilization

2. Methods of Forecasting Time Series Trend analysis Econometric Structural analysis End Use Engineering analysis

3. Time Series Forecasting Linear Trend – Fit the best straight line to the historical data and assume that the future will follow that line – Many methods exist for finding the best fitting line, the most common is the least squares method Polynomial Trend – Fit the polynomial curve to the historical data and assume that the future will follow that line – Can be done to any order of polynomial (square, cube, etc.) but higher orders are usually needlessly complex Logarithmic Trend – Fit an exponential curve to the historical data and assume that the future will follow that line

4. Econometric Forecasting Econometric models attempt to quantify the relationship between the parameter of interest (output variable) and several factors that affect the output variable Example: – Output variable – Explanatory variable • Economic activity • Weather (HDD/CDD) • Electricity price • Natural gas price • Fuel oil price

5. End Use Forecasting End use forecasting looks at individual devices, aka end uses (e.g., refrigerators) How many refrigerators are out there? How much electricity does a refrigerator use? How will the number of refrigerators change in the future? How will the amount of use per refrigerator change in the future? Repeat for another end uses

6. What is Energy Demand? Energy demand is the term used to describe the consumption of energy by human activity. It drives the whole energy system, influencing the total amount of energy used; the location of, and types of fuel used in the energy supply system; and the characteristics of the end use technologies that consume energy.

7. Energy Modeling Energy modeling or energy system modeling is the process of building computer models of energy systems in order to analyze them. Such models often employ scenario analysis to investigate different assumptions about the technical and economic conditions at play. Outputs may include the system feasibility, greenhouse gas emissions, cumulative financial costs, natural resource use, and energy efficiency of the system under investigation. A wide range of techniques are employed, ranging from broadly economic to broadly engineering. Mathematical optimization is often used to determine the least-cost in some sense. Models can be international, regional, national, municipal, or stand-alone in scope. Governments maintain national energy models for energy policy development. Energy models are usually intended to contribute variously to system operations, engineering design, or energy policy development.

8. Energy and its various forms Chemical energy – It is the energy stored in the bonds of chemical compounds (atoms and molecules).Chemical energy is released in a chemical reaction, often in the form of heat. For example, we use the chemical energy in fuels like wood, coal by burning them. Electrical energy – It is the energy carried by moving electrons in an electric conductor. It is one of the most common and useful forms of energy. Example – Lightning. Other forms of energy are also converted to electrical energy. For example, power plants convert chemical energy stored in fuels like coal into electricity through various changes in its form. Mechanical energy – It is the energy a substance or system has because of its motion. For example, machines use mechanical energy to do work. Thermal energy – It  is the energy a substance or system has related to its temperature, i.e., the energy of moving or vibrating molecules. For example, we use the solar radiation to cook food. Nuclear energy – It is the energy that is trapped inside each atom. Nuclear energy can be produced either by the fusion (combining atoms) or fission (splitting of atoms) process. The fission process is the widely used method. Gravitational energy – It is that energy held by an object in a gravitational field. Examples include water flowing down a waterfall.

9. Energy storage Energy storage is the capture of energy produced at one time for use later to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an accumulator or battery. Energy comes in multiple forms including radiation, chemical, gravitational potential, electrical potential, electricity, elevated temperature, latent heat and kinetic. Energy storage involves converting energy from forms that are difficult to store to more conveniently or economically storable forms. Some technologies provide short-term energy storage, while others can endure for much longer. Bulk energy storage is currently dominated by hydroelectric dams, both conventional as well as pumped. Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid. Common examples of energy storage are the recharg e able battery, which stores chemical energy readily convertible to electricity to operate a cell phone; the hydroelectric dam, which stores energy in a reservoir as gravitational potential energy; and ice storage tanks, which store ice frozen by cheaper energy at night to meet peak daytime demand for cooling. Fossil fuels such as coal and gasoline store ancient energy derived from sunlight by organisms that later died, became buried and over time were then converted into these fuels. Food (which is made by the same process as fossil fuels) is a form of energy stored in chemical form.

10. Bio-geo-chemical cycles The recycling of inorganic matter between living organisms and their nonliving environment are called biogeochemical cycles. The six most common elements associated with organic molecules—carbon, nitrogen, hydrogen, oxygen, phosphorus, and sulfur—take a variety of chemical forms and may exist for long periods in the atmosphere, on land, in water, or beneath Earth’s surface. Geologic processes, such as weathering, erosion, water drainage, and the seduction of the continental plates, all play a role in the cycling of elements on Earth.

11. Bio-geo-chemical cycles The six elements are used by organisms in a variety of ways. Hydrogen and oxygen are found in water and organic molecules, both of which are essential to life. Carbon is found in all organic molecules, whereas nitrogen is an important component of nucleic acids and proteins. Phosphorus is used to make nucleic acids and the phospholipids that comprise biological membranes. The cycling of these elements is interconnected

12. Water cycle Water is essential to all living things on Earth, because virtually all biochemical reactions take place in water. Water can dissolve almost anything, so it also provides an efficient way to transfer substances between and within cells. The water cycle  describes the continuous movement of water on, above, and below Earth’s surface. As it cycles, water moves from one exchange pool or reservoir to another. In different parts of the cycle, water exists as liquid, solid, or  gas . Therefore, the water cycle includes several physical processes by which water changes state.

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14. Water cycle As water passes through the water cycle, it can change to the gaseous state via three different processes: evaporation, sublimation, and transpiration. Evaporation: Occurs when water on Earth’s surface changes to water vapor. When the sun heats water, it gives water molecules enough energy to escape into the atmosphere. Water evaporates from soil on Earth’s surface, as well as from bodies of water. When salty ocean water evaporates, it leaves the salt behind. This process changes salt water to fresh water, which can then replenish the land.

15. Water cycle Sublimation: Occurs when ice and snow change directly to water vapor without first melting to form liquid water. Sublimation also occurs because of heat from the sun. Transpiration:  Occurs when plants release water vapor through leaf pores called stomata. Plants take up more water through their roots than they need for photosynthesis and other processes. Much of this excess water is given off via transpiration.

16. Carbon cycle Carbon is the basis of life on Earth. Chains of carbon bonded together form the backbone of many biochemical molecules. Carbon is also an important component of rocks and minerals, and carbon exists in the atmosphere in compounds such as carbon dioxide. The carbon cycle is the biogeochemical cycle in which carbon moves through the biotic and abiotic components of ecosystems. 

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18. Carbon cycle Cellular respiration by living things releases carbon into the atmosphere as carbon dioxide. Photosynthesis by producers (such as plants) removes carbon dioxide from the atmosphere and uses it to make organic carbon compounds. Carbon in organic compounds moves through ecosystem communities from producers to consumers, as modeled by food chains and food webs that show feeding relationships. Carbon is also released back into the environment when organisms decompose.

19. Nitrogen cycle Nitrogen makes up 78 percent of Earth’s atmosphere. It is also an important element in living things. Nitrogen is needed for proteins, nucleic acids, and many other organic molecules, including chlorophyll, without which plants and other photoautotroph's could not carry out photosynthesis. The nitrogen cycle is the biogeochemical cycle that recycles nitrogen through the biotic and abiotic components of ecosystems. The figure below shows how nitrogen cycles through a terrestrial ecosystem. Nitrogen passes through aquatic ecosystems in a similar cycle

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21. Nitrogen cycle When plants and other organisms die or release wastes, decomposers break down their organic compounds. In the process, they release nitrogen in the form of ammonium ions into the soil. The ammonium ions can be absorbed by plant roots. The ions can also be changed to nitrates by soil bacteria called nitrifying bacteria. Some of the nitrates are changed back to nitrogen gas by soil bacteria called denitrifying bacteria. This nitrogen returns to the atmosphere, thus completing the cycle.

22. Phosphorus cycle The phosphorus cycle is the biogeochemical cycle in which phosphorus moves through rocks, water, and living things. Unlike many other biogeochemical cycles, the atmosphere does not play a significant role in the cycling of phosphorus, because phosphorus and phosphorus-based compounds are not gases at the typical ranges of temperature and pressure found on Earth. Phosphorus cycles quickly through living things, but very slowly through the abiotic components of ecosystems, making the overall phosphorus cycle one of the slowest biogeochemical cycles

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24. Phosphorus cycle On land, most phosphorus is found in rocks. Weathering of rocks releases phosphorus in a soluble form that can be absorbed from soil by plant roots. Plants then use the phosphorus to make organic compounds, which can be passed on to consumers through feeding relationships. After organisms die, the phosphorus they contain is returned to soil by decomposers.

25. Growth and Change The largest single threat to the ecology and biodiversity of the planet in the decades to come will be global climate disruption due to the buildup of human-generated greenhouse gases in the atmosphere. People around the world are beginning to address the problem by reducing their carbon footprint through less consumption and better technology. But unsustainable human population growth can overwhelm those efforts, leading us to conclude that we not only need smaller footprints, but fewer feet

26. Growth and Change The globalization of the world economy, moreover, can mask the true carbon footprint of individual nations. Globally, recent research indicates that assumptions regarding declining fertility rates used by the Intergovernmental Panel on Climate Change to develop future emissions scenarios may be overly optimistic

27. Patterns of Consumption The way and total use of energy may be defined as its pattern. In general energy is classifies into two main groups: renewable and non-renewable. Renewable energy is the cleanest sources of energy and non-renewable sources are not environmental friendly source of energy. According to (Akhter Hossain, 2012 ) GDP and energy consumption of developing countries are increasing exponentially, whereas GDP and energy consumption of developed countries are increasing linearly

28. Patterns of Consumption Consumptionpattern  of energy includes consumption of coal, crude oil and natural gas, petroleum products, electricity. India will overtake China as the largest growth market for energy by late 2020s with the country’s energy consumption growing by more than 4.2% per annum, the fastest among all major economies of the world.

29. Patterns of Consumption

30. Commercial Generation of Power The energy sources that are used to generate electricity and that are available in the marketplace with a specific price are known as commercial energy sources. The most commercialized forms of commercial energy sources are electricity, coal, and advanced  petroleum products . They are used for electricity generation on the basis of industrial, agricultural, transportation, and commercial development of the different countries of the modern world. In the well-stabilized industrialized countries, commercialized fuels are the major source not only for financial benefit, but also for the many domestic responsibilities of the general population.

31. Commercial Generation of Power

32. Requirements of Power Generation The total amount of electricity used fluctuates depends highly on factors such as the time of the day, date and the weather. When demand varies operators must vary total output from the power plants. This is usually done through collaboration with other power plants thus keeping on power grid in an equilibrium. This adds a complication for the entire  power grid as it is often difficult to adjust the power output of large thermal power plants. Although confusing and often inefficient, Centralized generation is the most popular way of energy production and distribution in the world. The three major aspects of centralized generation are: Generation,  Transmission and Distribution .

33. Benefits of Power Generation Environmental and economic benefits of using commercial power generation include: Generating energy that produces no greenhouse gas emissions from fossil fuels and reduces some types of air pollution Diversifying energy supply and reducing dependence on imported fuels Creating economic development and jobs in manufacturing, installation, and more