This presentation is related to solar energy and it's related technologies

1. Solar power and Current
Solar Energy technologies
(unit-2)
Prepared By: Ambika Thakur, AP, Department of Civil Engineering

2. Introduction to solar
energy-
Solar power is a form of energy
harnessed from the power and heat of
the sun’s rays. It is renewable, and
therefore a “green” source of energy.
Solar energy is radiant light and heat
from the Sun that is harnessed using a
range of ever-evolving technologies
such as solar
heating, photovoltaics, solar thermal
energy, solar architecture, molten salt
power plants and artificial
photosynthesis.

3. Introduction to solar
energy-
 It is an important source of renewable energy and its technologies are broadly characterized as
either passive solar or active solar depending on how they capture and distribute solar energy or
convert it into solar power.
Active solar techniques include the use of photovoltaic systems, concentrated solar
power and solar water heating to harness the energy.
Passive solar techniques include orienting a building to the Sun, selecting materials with
favorable thermal mass or light-dispersing properties, and designing spaces that naturally
circulate air.

4. Introduction to solar
energy-
The large magnitude of solar energy available makes it a highly appealing source of
electricity. The United Nations Development Programme in its 2000 World Energy
Assessment found that the annual potential of solar energy was 1,575–
49,837 exajoules (EJ). This is several times larger than the total world energy
consumption, which was 559.8 EJ in 2012.
In 2011, the International Energy Agency said that "the development of affordable,
inexhaustible and clean solar energy technologies will have huge longer-term benefits. It
will increase countries’ energy security through reliance on an indigenous, inexhaustible
and mostly import-independent resource, enhance sustainability, reduce pollution, lower
the costs of mitigating global warming, and keep fossil fuel prices lower than otherwise.
These advantages are global. Hence the additional costs of the incentives for early
deployment should be considered learning investments.

5. Potential-
 The Earth receives 174 petawatts (PW) of
incoming solar radiation (insolation) at the
upper atmosphere.
Approximately 30% is reflected back to space
while the rest is absorbed by clouds, oceans and
land masses.
 The spectrum of solar light at the Earth's surface
is mostly spread across the visible and near-
infrared ranges with a small part in the near-
ultraviolet.
Most of the world's population live in areas with
insolation levels of 150–300 watts/m², or 3.5–
7.0 kWh/m² per day.

6. Potential-
 The potential solar energy that could be used by humans differs from the amount of solar
energy present near the surface of the planet because factors such as geography, time
variation, cloud cover, and the land available to humans limit the amount of solar energy that
we can acquire.
 Geography affects solar energy potential because areas that are closer to the equator have a
greater amount of solar radiation. However, the use of photovoltaics that can follow the
position of the sun can significantly increase the solar energy potential in areas that are farther
from the equator.
Time variation effects the potential of solar energy because during the nighttime there is little
solar radiation on the surface of the Earth for solar panels to absorb. This limits the amount of
energy that solar panels can absorb in one day. Cloud cover can affect the potential of solar
panels because clouds block incoming light from the sun and reduce the light available for solar
cells.

7. Potential

8. Solar energy technologies
1. Concentrated Solar Power (CSP)
Parabolic Trough Solar Thermal
System
Central Tower Solar Thermal
System
Linear Fresnel Solar Thermal
System
Parabolic Dish Solar Thermal
System

9. Concentrated Solar Power
(CSP)

10. Parabolic Trough Solar Thermal
System

17. Parabolic Dish solar system

18. Solar energy production

19. 2. Photovoltaic technology types
Crystalline technology - Crystalline silicon (c-Si) is the crystalline forms of silicon, either multi-
crystalline silicon (multi-Si) consisting of small crystals, or monocrystalline silicon(mono-Si), a
continuous crystal. Crystalline silicon is the dominant semiconducting material used
in photovoltaic technology for the production of solar cells. These cells are assembled into solar
panels as part of a photovoltaic system to generate solar power from sunlight.
Thin film technology- A thin film is a layer of material ranging from fractions of
a nanometer (monolayer) to several micrometers in thickness. The controlled synthesis of
materials as thin films (a process referred to as deposition) is a fundamental step in many
applications. A familiar example is the household mirror, which typically has a thin metal coating
on the back of a sheet of glass to form a reflective interface.

21. The photo-effect

23. Principle -
1. Protection layer
2. Front contact
3. Absorption Material
4. Metal back contact
5. Laminate film
6. Back glass
7. connectors

24. Principle-
Protection layer- usually made of glass or transparent plastic
Front contact- the front contact should be transparent so that light would get in touch with
cell.
Absorption material- the layer where absorbed light is converted into electric current,
semiconducting material is used like silicon.
Metal back contact- a conductor at the back which completes the electric circuit.
Laminate film- the structure which is water proof and insolated from heat.
Back glass- back side protection of the module with glass material.
Connectors- module is fitted with connector’s points and cable.

25. Arrangement of photovoltaic
system

26. Photovoltaic module-
A PV module consists of many PV cells wired
in parallel to increase current and in series to
produce a higher voltage. 36 cell modules are
the industry standard for large power
production.

27. Mounting structures-
Photovoltaic modules are hold with the help of mounting structures which are of the
following types-
Pole mounted- Solar panels are fixed on poles.
Ground mounted- Solar panels are fixed on ground with supporting arrangement
Roof mounted- Solar panels are fixed with roof arrangement.
Tracking mount- solar panels are fixed with such a moveable arrangement so that panel with
track the direction of sun. This one is expensive one.

28. Charge controller-
We will need a controller to extend the life of our photovoltaic system battery. The most basic
function of a controller is to prevent overcharging the battery.
If the batteries are allowed to overload routinely, their life expectancy will be reduced
dramatically.
A controller detects the battery voltage, and reduces or stops the charging current when the
voltage is high enough.

29. Battery-
The batteries accumulate the excess energy created by our PV system and store it to be used
at night or when there is no other energy input.
 Batteries can discharge quickly and produce more current that the charge source can produce
on its own, so pumps or motors can run intermittently.

30. Inverters
An inverter is an electrical device that converts direct current (DC) to alternating current (AC);
the resulting AC can be at any required voltage and frequency with the use of appropriate
transformers, switching and control circuits.
Inverters are required only if the building load is AC based, if building is equipped with DC load
then no need to provide inverters.
Load-
Load is simply anything which dissipates electrical energy.
 An electrical load is an electrical component or portion of a circuit that consumes (active) electric
power.

37. Thermal technology-

40. Solar pond-
 A solar pond is, simply, a pool of saltwater which collects and stores solar thermal energy. The
saltwater naturally forms a vertical salinity gradient also known as a "halocline", in which low-
salinity water floats on top of high-salinity water.
The layers of salt solutions increase in concentration (and therefore density) with depth. Below
a certain depth, the solution has a uniformly high salt concentration.
When the sun's rays contact the bottom of a shallow pool, they heat the water adjacent to the
bottom. When water at the bottom of the pool is heated, it becomes less dense than the cooler
water above it, and convection begins.

42. Solar pond-
 Solar ponds heat water by impeding this convection. Salt is added to the water until the lower
layers of water become completely saturated.
High-salinity water at the bottom of the pond does not mix readily with the low-salinity water
above it, so when the bottom layer of water is heated, convection occurs separately in the
bottom and top layers, with only mild mixing between the two.
This greatly reduces heat loss, and allows for the high-salinity water to get up to 90 °C while
maintaining 30 °C low-salinity water.This hot, salty water can then be pumped away for use in
electricity generation, through a turbine or as a source of thermal energy.

43. Advantages and disadvantages
The approach is particularly attractive for rural areas in developing countries. Very large area
collectors can be set up for just the cost of the clay or plastic pond liner.
The accumulating salt crystals have to be removed and can be a valuable by-product and a
maintenance expense.
No need for a separate collector.
The extremely-large thermal mass means power is generated night and day.
Relatively low-temperature operation means solar energy conversion is typically less than 2%.
Due to evaporation, non-saline water is constantly required to maintain salinity gradients.

44. Efficiency
The energy obtained is in the form of low-grade heat of 70 to 80 °C compared to an assumed
20 °C ambient temperature. According to the second law of thermodynamics the maximum
theoretical efficiency of a cycle that uses heat from a high temperature reservoir at 80 °C and
has a lower temperature of 20 °C is 1−(273+20)/(273+80)=17%.
By comparison, a power plant's heat engine delivering high-grade heat at 800 °C would have a
maximum theoretical limit of 73% for converting heat into useful work (and thus would be
forced to divest as little as 27% in waste heat to the cold temperature reservoir at 20 °C).
The low efficiency of solar ponds is usually justified with the argument that the 'collector',
being just a plastic-lined pond, might potentially result in a large-scale system that is of lower
overall levelized energy cost than a solar concentrating system.

45. Cost benefit analysis of Renewable
Energy
 Introduction-
Concern over global warming has led policy makers to accept the importance of reducing
green house gas emissions
 Renewable Energy system become quite favorable now a day because of national and
international policies
Still renewable energy technology is in early stage of implementation and unit cost of energy is
higher than conventional plant
But government provide incentive and cost based tariff to support renewable energy
Cost Benefit Analysis give a idea about the acceptability of any renewable energy plant

46. Cost Benefit Analysis-
Cost-Benefit Analysis applied to energy is the appraisal of all the costs and all the benefits of
an energy project taking account of present and future work
Cost Benefit Analysis (CBA) is little bit difference than Social Cost Benefit Analysis
Cost Benefit Analysis taking account of both financial benefit analysis and social cost benefit
Analysis

47. Choice of Cost Benefit Analysis
Decision Making is about choice
 For an Individual: It takes CBA for own benefit and future prospective. i.e project for
employee to make their future bright.
For a Company: Being Concerned with the profit earning capacity and income flow, they take
cash flow analysis.
 For the government: Decision making for the government is always a tough work, as it
account for profit and at the same time working to provide social benefit. This is the reason
because of that government project fail to become financial viable.

48. Method of Cost Benefit Analysis
In financial term, there is mainly four way of evaluating cost-benefit:
1. Benefits/Cost Ratio
2. Net Present Value (NPV)
3. Internal Rate of Return (IRR)

49. Renewable Energy Parameters for
C/B Analysis
The type of parameter for C/B analysis is depend upon the type of renewable technology
Here the list which affect the analysis of RET
1. Location of plant
2. Type of renewable energy
3. Technology status
4. Government involvement
5. Availability of technical staff
6. Economical consideration of society
7. Overall objective of installation
8. Climate condition
9. Risk of natural disaster

50. CBA parameters for Renewable
Energy

51. Conclusion
Most of the renewable energy project are less economical viable, because of high investment
and risk
associated with the project
 But still most of the government interested to increase the share of renewable energy.
Overall Cost Benefit analysis of renewable energy show that they are acceptable.
Main benefit of renewable energy is that it is clean form of energy and also socially acceptable
and help government to make a dream true to provide electricity to village.