This paper reviews in brief about solar radiation and pyranometer to measure the same.In order
to assess the availability of solar energy arriving on the earth, measurement of solar radiation at some locations
is essential. From measurements, empirical models are developed to predict the availability of solar energy at
other locations.[8] The common, commercial pyranometer design uses a thermopile, setting up a voltage
proportional to the radiation based on temperature readings. This necessitates temperature
compensation.Using photovoltaic silicon cells, instead of thermocouples, the global irradiance as well as its
direct and diffuse components to great accuracy can be measured. Pyranometer is basically just comprised of
two solar cells and a voltage amplifier.
This paper reviews in brief about solar radiation and pyranometer to measure the same.In order
to assess the availability of solar energy arriving on the earth, measurement of solar radiation at some locations
is essential. From measurements, empirical models are developed to predict the availability of solar energy at
other locations.[8] The common, commercial pyranometer design uses a thermopile, setting up a voltage
proportional to the radiation based on temperature readings. This necessitates temperature
compensation.Using photovoltaic silicon cells, instead of thermocouples, the global irradiance as well as its
direct and diffuse components to great accuracy can be measured. Pyranometer is basically just comprised of
two solar cells and a voltage amplifier.
Instruments for solar radiation measurement
Empirical equation for prediction of availability of solar radiation
Radiation on tilted surface
Types of solar collectors
kushsshah.blogspot.com
To access explanatory notes and download link, head to -
http://solarreference.com/all-you-need-to-know-about-solar-resource-measurement/
This presentation can also be downloaded for SFERA website (SFERA Summer School 2013). Amazing, concise, to the point document. For more quality resources, visit
http://solarreference.com
It state about a transducer by using ; we can harness the energy of sun for our own electrical purposes. Simply using a Renewable Resource for our consumption.
Fully compliant with all ISO-9060 specification criteria and supplied standard with a WRR (World Radiometric Reference) traceable calibration certificate, the 5600-0601 is a First Class Pyranometer as defined by the
World Meteorological Organization.
concentrated solar power technology - cspSANTHOSHRAJ60
From these slides, you can able to view the diverse application of concentrated solar power technology. And the thriving global market statistics of CSP technology. The future goals and current technology of CSP operation in India and globally.
One of the major hurdles holding solar power back is the inherent intermittency issues that come with having an atmosphere over your head. Solar cells on the Earth's surface can only generate electricity when the sun is in the sky, and for many countries, especially those in the Northern hemisphere, constant cloud cover can put a damper on a solar economy. But what if you could bypass the atmosphere altogether, what if you could harness solar energy directly from the sun, in space.
SOLAR POWER generation using solar PV and Concentrated solar power technologyPraveen Kumar
Concentrated Solar Power Technology
Power Tower Systems
Parabolic Trough Systems
Solar Dish Systems
Compact Linear Fresnel
Types, working, pros &cons
Scope in INDIA
Using Photo-Voltaic cells
-Working of PV Cells
-Considering different PV materials
-Efficiency, Comparing modules manufactured by different companies
-MPPT
- algorithms
-A view of different inverter topologies used
pyrheliometer
Instruments for solar radiation measurement
Empirical equation for prediction of availability of solar radiation
Radiation on tilted surface
Types of solar collectors
kushsshah.blogspot.com
To access explanatory notes and download link, head to -
http://solarreference.com/all-you-need-to-know-about-solar-resource-measurement/
This presentation can also be downloaded for SFERA website (SFERA Summer School 2013). Amazing, concise, to the point document. For more quality resources, visit
http://solarreference.com
It state about a transducer by using ; we can harness the energy of sun for our own electrical purposes. Simply using a Renewable Resource for our consumption.
Fully compliant with all ISO-9060 specification criteria and supplied standard with a WRR (World Radiometric Reference) traceable calibration certificate, the 5600-0601 is a First Class Pyranometer as defined by the
World Meteorological Organization.
concentrated solar power technology - cspSANTHOSHRAJ60
From these slides, you can able to view the diverse application of concentrated solar power technology. And the thriving global market statistics of CSP technology. The future goals and current technology of CSP operation in India and globally.
One of the major hurdles holding solar power back is the inherent intermittency issues that come with having an atmosphere over your head. Solar cells on the Earth's surface can only generate electricity when the sun is in the sky, and for many countries, especially those in the Northern hemisphere, constant cloud cover can put a damper on a solar economy. But what if you could bypass the atmosphere altogether, what if you could harness solar energy directly from the sun, in space.
SOLAR POWER generation using solar PV and Concentrated solar power technologyPraveen Kumar
Concentrated Solar Power Technology
Power Tower Systems
Parabolic Trough Systems
Solar Dish Systems
Compact Linear Fresnel
Types, working, pros &cons
Scope in INDIA
Using Photo-Voltaic cells
-Working of PV Cells
-Considering different PV materials
-Efficiency, Comparing modules manufactured by different companies
-MPPT
- algorithms
-A view of different inverter topologies used
pyrheliometer
basic renewable energy for Engineering Studentspankajnavale25
Renewables energy and basics by expert faculty at Government Institute and Engineering College from India. Better understanding best notes that one can. See.
Modeling Of a Bucket Air Cooler by Using Solar EnergyIJMER
In a conventional energy sources day to day decreasing in their energy levels. Going green and conservation as much energy as possible has become the focal point in their eyes of the world. There are many sources of energy available to us that will conserve our natural resources and decrease on harmful emissions that are destroying our environment. Many energy sources available in world like
hydro electrical, thermal, mechanical, solar, tidal, bio gas, wave, wind, geothermal, ocean thermal energy. Many incentives are now available to individuals and industries who implement the use of this ecofriendly environment through in this direction we are selected solar energy is main sources.Our design and construction of a bucket air cooler by using solar energy is new alternative to
conventional energy sources. We set out to create an air cooler that does not create any harmful
emissions in environment and provide no pollution in the surrounding. The solar power as the main energy sources to help in the project work. It is providing to cooling the enclosed space and also measured the temperature levels of before and after in absorbed enclosed space.
Studying the factors affecting solar power generation systems performance ( S...IJERA Editor
Solar energy is a huge, clean and renewable source of energy. It is also available everywhere on the earth. However, there are many technical and economic difficulties need to be solved so that solar energy becomes a strong competition against the traditional energy sources. Energy from the sun can be used successfully in electric power generation systems. Depending on the climate conditions and the use of a properly designed, installing and maintained system can meet a large demand in this request. Work plane for this research will include many steps, the first step will include an introduction to solar energy. The second step will be a short review of the solar energy availability, geometry, fields of applications and the largest commercial application of solar energy is the solar thermal power generation. In addition, the most common types of solar thermal power plants, the solar field, heat transfer fluid and the power conversion system types will be explained in detail. The third step, a simple analysis for the solar thermal power plant will be explained in order to predict the optimum conditions leading to maximum performance. Discussions of results will be the fourth step. The last step a conclusion and recommendation for future work will also be included.
Modeling Of a Bucket Air Cooler by Using Solar EnergyIJMER
In a conventional energy sources day to day decreasing in their energy levels. Going green
and conservation as much energy as possible has become the focal point in their eyes of the world.
There are many sources of energy available to us that will conserve our natural resources and decrease
on harmful emissions that are destroying our environment. Many energy sources available in world like
hydro electrical, thermal, mechanical, solar, tidal, bio gas, wave, wind, geothermal, ocean thermal
energy. Many incentives are now available to individuals and industries who implement the use of this
ecofriendly environment through in this direction we are selected solar energy is main sources.
Our design and construction of a bucket air cooler by using solar energy is new alternative to
conventional energy sources. We set out to create an air cooler that does not create any harmful
emissions in environment and provide no pollution in the surrounding. The solar power as the main
energy sources to help in the project work. It is providing to cooling the enclosed space and also
measured the temperature levels of before and after in absorbed enclosed space
future generation there may will be energy crises.
so to avoid these we are going for the technology named solar power plant through space satellite which provides continuous power supply . still research is going on this topic
Similar to Dr. Patel Badari Narayana, MGIT unit II Introduction to Solar Radiation (20)
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Student information management system project report ii.pdfKamal Acharya
Our project explains about the student management. This project mainly explains the various actions related to student details. This project shows some ease in adding, editing and deleting the student details. It also provides a less time consuming process for viewing, adding, editing and deleting the marks of the students.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
NO1 Uk best vashikaran specialist in delhi vashikaran baba near me online vas...Amil Baba Dawood bangali
Contact with Dawood Bhai Just call on +92322-6382012 and we'll help you. We'll solve all your problems within 12 to 24 hours and with 101% guarantee and with astrology systematic. If you want to take any personal or professional advice then also you can call us on +92322-6382012 , ONLINE LOVE PROBLEM & Other all types of Daily Life Problem's.Then CALL or WHATSAPP us on +92322-6382012 and Get all these problems solutions here by Amil Baba DAWOOD BANGALI
#vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore#blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #blackmagicforlove #blackmagicformarriage #aamilbaba #kalajadu #kalailam #taweez #wazifaexpert #jadumantar #vashikaranspecialist #astrologer #palmistry #amliyaat #taweez #manpasandshadi #horoscope #spiritual #lovelife #lovespell #marriagespell#aamilbabainpakistan #amilbabainkarachi #powerfullblackmagicspell #kalajadumantarspecialist #realamilbaba #AmilbabainPakistan #astrologerincanada #astrologerindubai #lovespellsmaster #kalajaduspecialist #lovespellsthatwork #aamilbabainlahore #Amilbabainuk #amilbabainspain #amilbabaindubai #Amilbabainnorway #amilbabainkrachi #amilbabainlahore #amilbabaingujranwalan #amilbabainislamabad
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Water Industry Process Automation and Control Monthly - May 2024.pdf
Dr. Patel Badari Narayana, MGIT unit II Introduction to Solar Radiation
1. Renewable Energy Sources For ECERenewable Energy Sources For ECE
B.Tech. IV Year II Sem. L/T/P/C
Course Code:
Name of The Faculty:
Dr. P. Badari Narayana
M.Tech (Energy Systems), P.hD.,
Associate Professor,
Dept. of Mechanical Engg.
Renewable Energy Sources Unit II
Topic:
SOLAR RADIATION
2. Syllabus * Unit II
• Solar Energy System
• Solar Radiation
• Availability
• Measurement & Estimation
• Solar Thermal Energy Conversion Devices and Storage
• Applications of Solar PV Conversion
• Applications of Solar Thermal Energy Conversion Devices
• Applications of Solar Energy Systems
4. Ways to Change Our Global Climate
Change energy from
the Sun
Change reflection from
the atmosphere and
planet
Change composition
of the atmosphere
5. • Radiation from the Sun
– Changes in energy radiated from the Sun
– Changes in Earth’s distance from the Sun
– Changes in Earth’s inclination relative to the Sun
• Atmospheric composition
– Changes in concentration of gases in atmosphere that absorb energy
(“greenhouse gases”)
• Through natural processes (volcanic emissions, emissions from
flora and fauna, soil, etc)
• Through the action of humans (consumption choices)
• Reflectivity of the planet
– Changing the reflectivity of the surface (snow, ice, forests, soot, etc)
– Changing the reflectivity of the atmosphere (clouds, aerosols)
How can these climate factors change?
6. Solar Radiation
• Sun is a star with a surface
temperature of ~5780K
• The Sun emits radiation
over a wide spectrum of
wavelengths out into space
• As radiation spreads out
into space, it is spread out
over an increasingly large
area 4pr2
• A small amount of that
energy is intercepted by
the Earth in it’s orbit
around the Sun. r is the radius at which the planet orbits the Sun
8. Major Uses of Solar Energy
oDaylight
oDrying Agricultural Products
oSpace Heating
oHeating Water
oGenerating Electrical Power
oConcentrating Solar Power
oPhotovoltaics
10. The Solar Resource
• Before we can talk about solar power, we need to talk about
the sun
• Need to know how much sunlight is available
• Can predict where the sun is at any time
• Insolation : incident solar radiation
• Want to determine the average daily insolation at the solar
system installation site
• Must choose effective locations and panel tilts of solar panels
10
11. The Sun and Blackbody Radiation
• The Sun
– 1.4 million km in diameter
– 3.8 x 1020 MW of radiated electromagnetic energy
• Black bodies
– Both a perfect emitter and a perfect absorber
– Perfect emitter – radiates more energy per unit of surface area than a
real object of the same temperature
– Perfect absorber – absorbs all radiation, none is reflected
• Temperature in Kelvin is temperature in Celsius + 273.16
11
12. Plank’s Law
• Plank’s law – wavelengths emitted by a blackbody depend
on temperature
8
5
3.74 10
14400
exp 1
E
T
• λ = wavelength (μm)
• Eλ = emissive power per unit area of black body (W/m2-μm)
• T = absolute temperature (K)
12
15. 288 K Blackbody Spectrum
The earth as a black body; note 0.7 m is red. Most all is infrared range, which is why
the earth doesn’t glow!
Figure 7.1
Area under curve is the total radiant power emitted
15
16. Radiation from
surface of Sun =
63 X 106 W/m2
Radiation at the top of
the Earth’s atmosphere
~1360 W/m2
(solar “constant”)
Earth is ~150 x 106
km from the Sun
Radiation from an
object falls off by the
inverse square of the
distance
Area of a sphere =
4pr2
Radius of sphere = r
17. Stefan-Boltzmann Law
• Total radiant power emitted is given by the
Stefan –Boltzmann law of radiation
4
E A Ts
• E = total blackbody emission rate (W)
• σ = Stefan-Boltzmann constant = 5.67x10-8 W/m2-K4
• T = absolute temperature (K)
• A = surface area of blackbody (m2)
17
18. Wien’s Displacement Rule
• The wavelength at which the emissive power per unit area
reaches its maximum point
max
2898
T
18
( )
absolute temperature
wavelength
T K
m
5800 , 0.5
288 , 10.1 considered as a blackbody
Sun:
Earth:
max
max
T K m
T K m
19. Extraterrestrial Solar Spectrum
19
FIGURE 4.2 The extraterrestrial solar spectrum compared with a 5800 K blackbody.
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition. Wiley-Blackwell
20. Solar Intensity: Atmospheric Effects
Sun photosphere
“AM” means “air mass”
Intensity
Extraterrestrial
sunlight (AM0)
Sunlight at sea level at 40°
N Latitude at noon (AM1.5)
20
21. Air Mass Ratio
• AM1.5 – assumed earth’s surface average
• Air mass ratio = 1 (“AM1”) – sun directly overhead
• AM0 – no atmosphere
2
1
1
air mass ratio =
s n
:
i
m
h
h
As sunlight transits the atmosphere, energy is absorbed
21
FIGURE 4.3
The air mass ratio m is a measure of the amount
of atmosphere the sun's rays must pass through
to reach the earth's surface.
Masters, Gilbert M. Renewable and Efficient Electric Power
Systems, 2nd Edition. Wiley-Blackwell
22. Solar Spectrum on Earth’s Surface
m is higher when the sun is
closer to the horizon
Notice blue light attenuation
with higher m,
sun appears reddish at
sunrise and sunset
22Blue is 450 nm, Red is 700 nm
C.A. Gueymard, The sun’s total and
spectral irradiance for solar energy
applications and solar radiation models.
Solar Energy, vol. 76, 423-453 (2004)
https://en.wikipedia.org/wiki/Simple_Model_of_the_Atmospheri
c_Radiative_Transfer_of_Sunshine_(SMARTS)#cite_ref-1
23. INDIA is well above the equator(0* latitude)..
The latitudinal extent of INDIA is-
8*4′28″ N to 37*17′53″ N.. TROPIC OF CANCER(23.5*N latitude)cuts INDIA into exactly 2
equal halves..(see in the image above).This imaginary line passes through 8 INDIAN states..
24. India is well above the Equator, India lies to the north of equator.
25. The Earth’s Orbit
FIGURE 4.5 The tilt of the earth's spin axis with respect to the ecliptic
plane is what causes our seasons. “Winter” and “Summer” are
designations for the solstices in the Northern Hemisphere.
25
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition. Wiley-Blackwell
26. Solar Declination
• δ varies between +/- 23.45˚
• Assuming a sinusoidal relationship, a 365 day year,
and n =81 is the spring equinox,
360
23.45sin 81
365
n
26
FIGURE 4.6
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition
27. The Sun’s Position in the Sky
• Predict where the sun will be in the sky at any time
• Pick the best tilt angles for photovoltaic (PV) panels
Solar declination
27
FIGURE 4.6
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition
28. Solar Noon and Collector Tilt
• Solar noon – sun is directly
over the local line of longitude
• At solar noon, sun’s rays are
to the collector’s face
28
Tilt of 0 is straight up,
Tilt of 90 is perpendicular
FIGURE 4.8
A south-facing collector tipped up to an angle equal to its latitude is
perpendicular to the sun's rays at solar noon during the equinoxes
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2d Ed. Wiley-Blackwell
29. Altitude Angle βN at Solar Noon
• Altitude angle at solar noon βN – angle between the sun and the
local horizon
• Zenith – perpendicular axis at a site
90N L
FIGURE 4.9 The altitude angle of the sun at solar noon
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition. Wiley-Blackwell
30. Solar Position at Any Time of Day
30
ss
FIGURE 4.10
Masters, Gilbert M. Renewable and Efficient Electric Power
Systems, 2nd Edition. Wiley-Blackwell
The sun's position is described by
• Altitude angle
• Azimuth angle ϕS
By convention, ϕS is considered ‘+’ before solar noon
ss
31. Altitude Angle and Azimuth Angle
• Hour angle H – earth rotation
(degs) until sun is overhead
• Earth rotates at 15˚/hr….
• At 11 AM solar time, H = +15˚
(the earth needs to rotate 1 more
hour)
• At 2 PM solar time, H = -30˚
15
hour angle hours before solar noon
hour
H
31
32. Sun Path Diagrams for Shading Analysis
• Shading PV panel (or portion) greatly reduces energy output
• Able to model the sun’s position at all times Site the PV array
Using Sun Path Diagram
• Sketch azimuth & altitude angles of trees, buildings, other
obstructions
32
• Sections Covered on the
Sun Path Diagram indicate
times when the site will be
shaded
34. Sun Path Diagram for Shading Analysis
• Trees to the southeast, small building to the southwest
• Can estimate the amount of energy lost to shading
34
FIGURE 4.14 A sun path diagram with superimposed obstructions makes it easy to
estimate periods of shading at a site
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition. Wiley-Blackwell
35. Clear Sky Direct-Beam Radiation
• Direct beam radiation IBC – passes in a straight line
through the atmosphere to the receiver
• Diffuse radiation IDC – scattered by molecules in the
atmosphere
• Reflected radiation IRC – bounced off a
surface near the reflector
35
36. Extraterrestrial Solar Insolation I0
• Starting point for clear sky radiation
calculations
• I0 passes perpendicularly through an
imaginary surface outside of the earth’s
atmosphere
• Ignoring sunspots, I0 can be written as
• SC = solar constant = 1.377 kW/m2
• n = day number
2
0
360
SC 1 0.034cos (W/m )
365
n
I
In 1 year, < .5 I0
reaches earth’s surface
as a direct beam
36
I0 varies only due to
eccentricity in the
earth's orbit
37. Attenuation of Incoming Radiation
km
BI Ae
• IB = portion of the radiation
that reaches earth’s surface
• A = apparent extraterrestrial
flux
• k = optical depth
• m = air mass ratio
The A and k values are location dependent, varying with
values such as dust and water vapor content
37
38. Calculating Air Mass Ratio M
• At any point in time, the air mass ratio (m) depends upon the sun’s
altitude angle,
• Example: For Urbana L = 40.1 N, on Spring Equinox = 0, say H = +15
(one hour before local noon)
38
sin cos cos cos sin sinL H L
2
708sin 1417 708sinm
sin cos 40.1 cos 0 cos 15 sin 40.1 sin 0
sin 0.7388 47.6
1.35m
39. Solar Insolation on a Collecting Surface
• Direct-beam radiation is just a function of the
angle between the sun and the collecting surface
(i.e., the incident angle q:
• Diffuse radiation is assumed to be coming from
essentially all directions to the angle doesn’t
matter; it is typically between 6% and 14% of the
direct value.
• Reflected radiation comes from a nearby surface,
and depends on the surface reflectance, r,
ranging down from 0.8 for clean snow to 0.1 for a
shingle roof.
cosBC BI I q
39
40. Tracking Systems
• Most residential solar PV systems have a fixed mount, but
sometimes tracking systems are co₹t effective
• Tracking systems are either
– single axis (usually with a rotating polar mount [parallel to
earth’s axis of rotation), or
– two axis (horizontal [altitude, up-down] and vertical [azimuth,
east-west]
– Tracking systems add cost & maintenance needs
40
41. Tracking System Performance
41
FIGURE 4.30 Comparing clear-sky insolation striking various trackers and fixed and fixed-tilt
collector on May 21, latitude 33.7° (Atlanta). Numbers in parentheses are kWh/m2/d
Masters, Gilbert M. Renewable and Efficient Electric Power Systems, 2nd Edition. Wiley-Blackwell
42. Monthly and Annual Insolation
• For a fixed system the total annual output is somewhat
insensitive to the tilt angle, but there is a substantial variation
in when the most energy is generated
42
• Peak insolation is usually considered 1
kW/m2
• Which is known as "One Sun.“
• Insolation units: kWh/m2 per day,
which is equivalent
to hours per day of peak insolation
44. Ken Youssefi Introduction to Engineering – E10 44
A major drawback of most renewable energy
sources is the high cost. To spur a huge rise in
use, prices must come down and efficiencies
must go up (better technology)
Typical efficiencies for commercial applications:
15% - 20%
Panasonic company has the most efficient, 25.6%
45. Ken Youssefi Introduction to Engineering, E10 45
Reported timeline of solar cell energy conversion efficiencies
(National Renewable Energy Lab.)
46. Factors Affecting Efficiency
• Sunlight consists of a spectrum of
wavelengths – semiconductor materials
cannot respond to the full spectrum
• As much as 30% of light is reflected from
the surface of the cell (only absorbed
light can produce electricity)
• Impurities can cause the charge to
“recombine” and therefore not generate
electricity
47. Other Factors Affecting Efficiency
• Angle of incidence of the sun
• Dirt, snow, or other impurities on cell surface
• Shading (even a small amount of shading
reduces output dramatically)
• Cloud cover
48. Atoms
Protons - carrying positive charge
Neutrons - charge neutral
Electrons - carrying negative charge
An atom is composed of 3 particles:
• Nucleus consists of Protons and
neutrons and electrons orbit
around the nucleus
• The number of protons and
electrons are the same, therefore
an atom, as a whole, is electrical
charge neutral.
• Different materials have different
number of particles in their atoms.
49. Atoms
Each atom has a specific number of electrons,
protons and neutrons. But no matter how many
particles an atom has, the number of electrons
usually needs to be the same as the number of
protons. If the numbers are the same, the atom is
called balanced, and it is very stable.
So, if an atom had six protons, it should also have six
electrons. The element with six protons and six
electrons is called carbon. Carbon is found in
abundance in the sun, stars, comets, atmospheres of
most planets, and the food we eat. Coal is made of
carbon; so are diamonds
50. Atoms
Ken Youssefi Introduction to Engineering – E10 50
• In some materials, atoms have loosely attached
electrons. An atom that loses electrons has more
protons than electrons and is positively charged. An
atom that gains electrons has more negative
particles and is negatively charge. A "charged" atom
is called an "ion."
• Electrons can be made to move from one atom to
another. When those electrons move between
the atoms, a current of electricity is created. The
electrons move from one atom to another in a
"flow." One electron is attached and another
electron is lost.
51. Conductors & Insulators
Ken Youssefi Introduction to Engineering – E10 51
Insulators
Insulators are materials that hold their electrons very tightly
(high bonding force). Electrons do not move through them
very well.
Rubber, plastic, cloth and glass are good insulators and have
very high resistance.
52. Conductors & Insulators
Ken Youssefi Introduction to Engineering – E10 52
Conductors
Other materials have some loosely held electrons,
which move through them very easily. These are called
conductors.
Most metals – like copper, aluminum or steel – are
good conductors.
53. Electric Current
Ping Hsu Introduction to Engineering – E10 53
• Electric current is the flow of positive
charge. 1 Amp = 1 Coulomb per second.
• Electric current is an effect of the flow of
free electrons which carries negative
charge. (6.28 x 1018 electrons = -1
Coulomb).
• Positive charge flow (current) and negative
charge flow (electron flow) are the same in
magnitude but in the opposite direction.
• By convention, current flow is used in
analyzing circuits. Electron flow is used
ONLY for describing the physical behavior
of electric conduction of materials.
Water flow
(electron flow)
Bubble
Flow
(current
flow)
54. Clicker Question
Ken Youssefi Introduction to Engineering – E10 54
Q1. What type of electric charge does an
atom carry?
(a) Positive charge
(b) Negative charge
(c) Neutral
(d) Radiation charge
(e) Magnetic charge
55. Clicker Question
Ken Youssefi Introduction to Engineering – E10 55
Q2. What type of electric charge does the
nucleus of an atom carry?
(a) Positive charge
(b) Negative charge
(c) Neutral
(d) Radiation
(e) Magnetic
56. Silicon atom has 14 electrons and 14 protons.
The outer 4 electrons, together with the 4 from their adjacent atoms, form “octets”
which is a stable structure. Electrons don’t “wandering off” (i.e., free) from this
structure.
56
14+ 14- 14+ 14-
14+ 14- 14+ 14--
14+ 14- 14+ 14-
14+ 14-
14+ 14-
14+ 14-
e-e-
e-e-
e-
e-
e-
e-
e-
N
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
14+
Ping Hsu
58. 58
When sunlight strikes a piece of Silicon, however, the solar
energy knocks and frees electrons from their atom structure
(the octets structure)
14+ 14- 14+ 14-
14+ 14- 14+ 13-
14+ 14- 14+ 14-
14+ 14-
14+ 14-
14+ 14-
1-
Heat or light
Freed electron
e-e-
e-e-
e-
e-
e-
e-
e-
N
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
e-
14+
Ping Hsu
59. For simplicity, we only show the charge of free electrons
(-1) and the corresponding positive charges (14-13= +1) at the
nucleus.
59
Heat or light
Freed electron
The freed electrons randomly move within the material. This
random motion of charge cannot be utilized for power
generation. In order to utilize the energy from the sun, this
flow of charges must be directed in one direction.
Ping Hsu
60. N-type (Negative Type) Semiconductor
Introduction to Engineering – E10
A small amount of impurity (doping) such as Phosphorus, arsenic , or antimony
is mixed into a Silicon base and this forms an N-type material. Antimony has 5
outer orbit electrons. Therefore, when bonded with Silicon, there is one electron
extra to form the stable octet configuration. This extra electron is loosely
bonded.
These loosely bonded electron helps with conducting current. The conductivity
is not nearly as good as a true conductor. That’s why it is called a
“semiconductor”.
61. P-type (Positive Type) Semiconductor
A small amount of impurity such as boron, aluminum or gallium is
mixed into a Silicon base. Boron has 3 outer orbit electrons.
Therefore, when bonded with Silicon, it is one electron short to
form the stable octet configuration. This type materials can, on
the other hand, easily accept one electron.
For simplicity, this characteristic of ‘easily accepting electron’ is
represented by a “hole” with a positive charge and a
corresponding negative charge at the nucleus.
63. 63
• Although there are free electrons and holes in N-type and P-type
materials, they are charge neutral.
• N-type materials conduct electric current (supports movement of
charge) by the free electrons ----- just like metal but with fewer
free electrons than that in metal.
Water flow
(electron flow)
Bubble
Flow
(current
flow)
• P-type materials conduct electric current
(supports movement of charge) by electric
“holes”. When electrons jump from hole to
hole in one direction, the holes appear moving
in the opposition direction. Similar to the
situation when you turn a filled water bottle
upside down; as the water moves downward
(electrons), the bubbles (holes) moves up.
Ping Hsu
64. 64
Interesting things happen when you put an N-type material in
contact with a P-type material.
P-type (neutral) N-type (neutral)
Before making the contact:
Ping Hsu
65. 65
P-type
(Negatively charged!)
N-type
(Positively charged!)
In the boundary layer, the free electrons in the N-type materials
combine with the holes in the P-type. Consequently, the P-type
side of the boundary layer is negatively charged and N-type side
is positively charged.
Negative charge in P-type material prevents the free electrons in the
rest of the N-type material to continue to migrate into the P-type.
(Negative charge repels negative charged free electrons.)
The boundary lay is called PN-junction or depletion region.
boundary
layer
Ping Hsu
67. When sunlight strikes atoms in the P-N Junction and knocks
out more electrons (and creates corresponding holes), the
free electrons are expelled by the negative charge on the
P-type side and hence move towards the N-type side.
P-type
(Negatively charged)
N-type
(Positively charged)
sunlight
68. If a load is connected across the cell, electric current is formed
and the energy is transmitted to the load.
P-type N-type
sunlight
pn junction
Pn junction
Pn junction
71. Q3. The purpose of the PN junction in a solar
cell is
(a) to generate free electrons
(b) to generate holes
(c) to isolate P and N materials
(d) to accelerate the electrons flow
(e) to direct the direction of electron flow
Clicker Question
72. Q4. P-type material conducts current by
(a) Metallic element
(b) Free electron
(c) Electric ‘holes’
(d) Conductor
(e) Insulator
Clicker Question
73. Photovoltaic Cell
Solar panels capture sunlight and convert it to electricity using photovoltaic
(PV) cells like the one illustrated above.
74. Major Components in a typical PV installation
• PV Panels – solar cells
• Charge Controller
1. Match the panel voltage
and battery voltage
2. Extract maximum power
from the panel
3. Prevent over-charge
• Battery - hold energy
• Inverter - convert DC to
60Hz AC for compatibility
with the power line voltage.