The document discusses various methods of forecasting energy demand including time series analysis, econometric modeling, and end use forecasting. It then provides details on time series forecasting methods like linear trend analysis and polynomial trend analysis. Econometric forecasting attempts to quantify relationships between output variables and factors that affect them. End use forecasting examines individual devices and forecasts changes in their number and energy use over time.

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 rechargeable 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