3. Introduction: The energy of a body is its capacity to do work. It is measured
the total amount of work that the body can do.
Different forms of energy are:
1. Mechanical energy (kinetic and potential)
2. Thermal (or) Heat energy
3. Chemical energy
4. Electrical energy
5. Nuclear energy
6. Electromagnetic energy
7. Gravitational energy
The S.I unit of energy is Joule or KJ or Watt.h.
4. Conventional and Non-Conventional sources energy
Conventional energy sources : The non-renewable sources of energy, which, if exhausted,
can not be replenished in a short time. Their reserves are limited and are considered very
precious.
1. Fossil fuel energy
a. Coal
b. Petroleum
c. Natural Gas
2. Hydraulic energy
3. Nuclear energy
Non-Conventional Energy Sources: The sources of energy which are being produced
continuously in nature and are inexhaustible are called renewable sources of energy
(or) non-conventional energy. Some of these sources are:
(a) Wind energy
(b) Tidal energy
(c) Solar energy
(d) Bio Energy (e) Energy from urban waste
5. (a) Wind energy
Winds are caused because of two factors.
1. The absorption of solar energy on the earth’s surface and in the atmosphere.
2. The rotation of the earth about its axis and its motion around the Sun.
A wind mill converts the kinetic energy of moving air into Mechanical
energy that can be either used directly to run the Machine or to run the
generator to produce electricity.
(b) Tidal energy
. Tides are generated primarily by the gravitational attraction between the earth
and the Moon. They arise twice a day in Mid-Ocean. The tidal range is only a
Meter.
Basically in a tidal power station water at high tide is first trapped in a
artificial basin and then allowed to escape at low tide. The escaping water is
used to drive water turbines, which in turn drive electrical generators
6. (c) Solar energy
Brief history of solar energy (or) Importance of solar energy:
Energy from the sun is called solar energy. The Sun’s energy comes
from nuclear fusion reaction that take place deep in the Sun. Hydrogen
nucleus fuse into helium nucleus. The energy from these reactions flow out
from the sun and escape into space.
4. Bio Energy:
This type of energy is obtained from organic matter.
It is of two kinds:
(i) Bio Gas:
Bio Gas is obtained from Gobar Gas Plant by putting cow dung into the plant. Besides
producing gas this plant converts gobar into manure. It can be used for cooking, lighting
and generation of electricity. 26.5 lakh bio gas plants had been established by the year
2003-04. They produce more than 225 lakh tonnes of manure. About 1828 large
community bio gas plants have been established in the country.
(ii) Bio Mass:
It is also of a source of producing energy through plants and trees. The purpose of bio
mass programme is to encourage afforestation for energy. So that fuel for the generation
of energy based on gas technique and fodder for the cattle could be obtained, 56 MW
capacity for the generation of bio mass energy has been installed.
7. 5. Energy from Urban Waste:
Urban waste poses a big problem for its disposal. Now it can be used for
generation of power. In Timarpur (Delhi) a power Ration of 3.75 MW capacity
has been set up to generate energy from the garbage
8. Merits of Non-conventional Source of Energy
Non-polluting: The major advantage of these non-conventional sources is that
they are non-polluting, unlike the other sources. The burning of firewood and
fossil fuels result in air pollution. This can be avoided by using these non-
conventional sources.
• Inexhaustible: The major problem while using conventional sources especially
fossil fuels is that they are exhaustible sources. It takes millions of years for
them to be renewed and replenished. But non-conventional sources are
renewable sources that do not get exhausted.
• Safe: Non-conventional energy extraction is safer. Many accidents occur while
extracting energy from mines. These accidents can be completely avoided.
• Low running cost: The cost of energy production and extraction is much lesser
for non-conventional sources if the initial cost of establishment is borne.
• Energy production: The non-conventional sources especially nuclear energy
results in the production of huge quantities of energy compared to the
conventional energy sources.
9. Demerits of Non-conventional Source of Energy
Inconsistent, Unreliable Supply
Low Efficiency Levels
Location-Specificity Means Lower Chances of Universality
Not Every Non-Conventional Energy Source Is Commercially Viable
High Capital Cost
10. The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation
is energy that travels and spreads out as it goes – the visible light that comes from a
lamp in your house and the radio waves that come from a radio station are two types
of electromagnetic radiation. The other types of EM radiation that make up the
electromagnetic spectrum are microwaves, infrared light, ultraviolet light, X-
rays and gamma-rays.
11. SOLAR THERMAL COLLECTOR..
A SOLAR THERMAL COLLECTORS are special kind of heat exchangers
that transform solar radiation energy to internal energy of the transport
medium.
The major component of any solar system is the solar collector.
Collector is a device which absorbs the incoming solar radiation,
converts it into heat, and transfers this heat to a fluid (usually air, water,
or oil)flowing through the collector.
The solar energy thus collected is carried from the circulating fluid either
directly to the hot water or space conditioning equipment, or to a
thermal energy storage tank from which can be drawn for use at night
and/or cloudy days.
For domestic/ industrial water heating and space heating purposes the
solar thermal collectors are classified as..
1. FLAT PLATE SOLAR COLLECTORS.
AND
2. EVACUATED TUBE SOLAR COLLECTORS.
12.
13.
14. Solar Power Plant: Solar power plant is based on the conversion of sunlight into
electricity, either directly using photovoltaic (PV), or indirectly using concentrated
solar power (CSP). Concentrated solar power systems use lenses or mirrors and
tracking systems to focus a large area of sunlight into a small beam. Photovoltaic
converts light into electric current using the photoelectric effect. Concentrated solar
power plants first appeared in the 1980s
Components of Solar Power Plant:
1)Solar module
2) Controller
3) Batteries
4) Inverters
5) Lighting load
15.
16. Solar Module
Solar panel refers to a panel designed to absorb the sun's rays as a source of
energy for generating electricity or heating. A photovoltaic (in short PV) module is
a packaged, connected assembly of typically 6×10 solar cells.
Solar Photovoltaic panels constitute the solar module of a photovoltaic system
that generates and supplies solar electricity in commercial and residential
applications. Each module is rated by its DC output power under standard test
conditions, and typically ranges from 100 to 365 watts.
An individual PV cell typically produces 0.6 watts and are joined in an module to
produce the required power
17. Controller:
Controller's main function is to make solar power system is always in the
vicinity of the maximum power generation in order to obtain maximum
efficiency.
The charge control usually the PWM (pulse width modulation) control, so
that the whole system is always running at maximum power point Pm near
the area.
Discharge control mainly refers to when the battery power shortage, system
failures, such as open or reversed when the battery cut off switch.
D.C. to A.C. Converter (Inverter)
Solar panels produce direct current which is required to be converted into
alternating current to be supplied to homes or power grid.
18. Battery:
Batteries are used to produce the power back or store the excess energy produced
during day, to be supplied during night
An electric battery is a device consisting of two or more electrochemical cells that
convert stored chemical energy into electrical energy.
Each cell has a positive terminal, or cathode, and a negative terminal, or anode.
The terminal marked positive is at a higher electrical potential energy than is the
terminal marked negative.
The terminal marked negative is the source of electrons that when connected to an
external circuit will flow and deliver energy to an external device.
When a battery is connected to an external circuit, electrolytes are able to move as
ions within, allowing the chemical reactions to be completed at the separate
terminals and so deliver energy to the external circuit.
It is the movement of those ions within the battery which allows current to flow
out of the battery to perform work. Although the term battery technically means a
device with multiple cells, single cells are also popularly called batteries.
19. Advantages:
Solar energy is a clean and renewable energy source.
Once a solar panel is installed, solar energy can be produced free of charge.
Solar energy will last forever whereas it is estimated that the world’s oil reserves
will last for 30 to 40 years.
Solar energy causes no pollution.
Solar cells make absolutely no noise at all. On the other hand, the giant machines
utilized for pumping oil are extremely noisy and therefore very impractical.
Very little maintenance is needed to keep solar cells running. There are no
moving parts in a solar cell which makes it impossible to really damage them.
In the long term, there can be a high return on investment due to the amount of
free energy a solar panel can produce, it is estimated that the average household
will see 50% of their energy coming in from solar panels
20. Disadvantages
Solar panels can be expensive to install resulting in a time-lag of many years for
savings on energy bills to match initial investments.
Electricity generation depends entirely on a countries exposure to sunlight; this
could be limited by a countries climate.
Solar power stations do not match the power output of similar sized
conventional power stations; they can also be very expensive to build.
Solar power is used to charge batteries so that solar powered devices can be
used at night. The batteries can often be large and heavy, taking up space and
needing to be replaced from time to time