Energy and power, solar astronomy. (Lecture 4)

Сентябрь 6, 2022

Главная
Астрономия
Energy and power, solar astronomy. (Lecture 4)

Содержание

2. Lecture # 4, Solar Astronomy Energy Units - Calorie Calorie (cal) = heat to increase by
3. Lecture # 4, Solar Astronomy Very Small Energy Unit, eV Electronvolt (eV) - the amount of
4. Lecture # 4, Solar Astronomy Energy unit conversion factors
5. Lecture # 4, Solar Astronomy Energy and Power If power is constant E = P ·
6. Lecture # 4, Solar Astronomy Power Units Watt (W) = using one J in one second.
7. Lecture # 4, Solar Astronomy Power vs. Energy Thus, power is the rate of the energy
8. Lecture # 4, Solar Astronomy Solar Energy The SUN: Fusion in the sun – the process
9. Lecture # 4, Solar Astronomy The light: particle, wave Particle and wave Light speed, c =
10. Lecture # 4, Solar Astronomy Electromagnetic Spectrum
11. Lecture # 4, Solar Astronomy Sun Spectrum
12. Lecture # 4, Solar Astronomy The Sun Sun has a capacity of 3.86×1026 W 3.86×108 EJ/s
13. Lecture # 4, Solar Astronomy How this energy is generated?
14. Lecture # 4, Solar Astronomy How this energy is generated? About 74% of the Sun's mass
15. Lecture # 4, Solar Astronomy How this energy is generated? The Sun has a surface temperature
16. Lecture # 4, Solar Astronomy How this energy is generated? The Sun diameter: 1.4 106 km
17. Lecture # 4, Solar Astronomy How this energy is generated? It was Albert Einstein who provided
18. Lecture # 4, Solar Astronomy
19. Lecture # 4, Solar Astronomy
20. The Sun Lecture # 4, Solar Astronomy
21. Lecture # 4, Solar Astronomy
22. Lecture # 4, Solar Astronomy
23. Lecture # 4, Solar Astronomy
24. NASA caption: Giant magnetic loops dance on the sun’s horizon in concert with the eruption of
25. Lecture # 4, Solar Astronomy
26. Lecture # 4, Solar Astronomy
27. Lecture # 4, Solar Astronomy
28. Sun surface videos https://www.youtube.com/watch?v=ipvfwPqh3V4 https://www.youtube.com/watch?v=0WW1HN0iG0M https://www.youtube.com/watch?v=lpzCSZ7Eerc https://www.youtube.com/watch?v=nmDZhQAIeXM Lecture # 4, Solar Astronomy
29. Solar wind The total number of particles carried away from the Sun by the solar wind
30. Elementary particles flow from Sun – Solar Wind http://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.htmlhttp://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.html http://www.bbc.com/news/science-environment-28690559http://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.html http://www.bbc.com/news/science-environment-28690559 https://www.youtube.com/watch?v=sBWPCvdv8Bk Lecture # 4, Solar
31. Solar Wind Lecture # 4, Solar Astronomy
32. Aurora Borealis https://www.youtube.com/watch?v=hsMW7zbzsUs https://www.youtube.com/watch?v=Vdb9IndsSXk https://www.youtube.com/watch?v=pjgvGiEHlNs Lecture # 4, Solar Astronomy
33. Lecture # 4, Solar Astronomy How this energy is generated? In 1920 Sir Arthur Eddington proposed
34. This actually corresponds to a surprisingly low rate of energy production in the Sun's core—about 0.3
35. Lecture # 4, Solar Astronomy
36. Lecture # 4, Solar Astronomy How this energy is generated? most of the elements in the
37. Lecture # 4, Solar Astronomy 1.5 The future of energy resources Solar Constant = 1366 W/sq.m.
38. Lecture # 4, Solar Astronomy
39. Earth's rotation Earth's rotation tilts about 23.5 degrees on its pole-to-pole axis, relative to the plane
40. Lecture # 4, Solar Astronomy
41. Solar Constant Lecture # 4, Solar Astronomy
42. Now: go to the article http://www.wired.com/2015/07/pluto-new-horizons-2/ Lecture # 4, Solar Astronomy
43. Lecture # 4, Solar Astronomy
44. Solar radiation bouncing atmosphere the theoretical daily-average insolation at the top of the atmosphere, where θ
45. Lecture # 4, Solar Astronomy
46. Airmass In astronomy, airmass is the optical path length through Earth's atmosphere for light from a
47. Earth Atmosphere Lecture # 4, Solar Astronomy
48. Rayleigh scattering Lecture # 4, Solar Astronomy
49. Airmass Lecture # 4, Solar Astronomy “Airmass” normally indicates relative airmass, the path length relative to
50. Airmass Atmosphere height = 8.5 ÷ 11 km. Earth's mean radius is 6371 km. Airmass abbreviation:
51. Earth Atmosphere Lecture # 4, Solar Astronomy
52. Numbers to remember Solar constant = 1366W/m2 Attenuation at AM1 = 27% Scattered light capacity =
53. Air mass calculations Lecture # 4, Solar Astronomy
55. Скачать презентацию

Слайд 2

Lecture # 4, Solar Astronomy
Energy Units - Calorie
Calorie (cal) = heat

to increase by 1°C the 1 gram of water.
1 cal ≈ 4.184 Joules

Слайд 3

Lecture # 4, Solar Astronomy
Very Small Energy Unit, eV
Electronvolt (eV) -

the amount of kinetic energy gained by a single unbound electron when it passes through an electrostatic potential difference of one volt, in vacuum.

1 eV = 1.6×10−19 J

Слайд 4

Lecture # 4, Solar Astronomy
Energy unit conversion factors

Слайд 5

Lecture # 4, Solar Astronomy
Energy and Power
If power is

constant
E = P · t, P = E/t
If power is variable and depends on time
E = ∫P(t)dt, P(t) = dE(t)/dt

Слайд 6

Lecture # 4, Solar Astronomy
Power Units
Watt (W) = using one J

in one second.
kW = 1000 W
Horsepower = 735 W = 0.735 kW
MW = 1000 kW

Слайд 7

Lecture # 4, Solar Astronomy
Power vs. Energy
Thus, power is the rate

of the energy use.
Energy is what you pay for repeatedly, as much as you use the energy, the kWh-s – variable, operational cost.
Power is the capacity to use the energy
You pay for the capacity usually upfront, fixed or installation cost.
E.g. if you decide to buy an air conditioner, you need to solve a power sizing problem. You pay the fixed amount. Later you usually use only a fraction of the total capacity.

Слайд 8

Lecture # 4, Solar Astronomy
Solar Energy
The SUN:
Fusion in the sun –

the process
Temperature of the suncrust, black-body radiation – BBR
Photon energy, light speed, duality
Electromagnetic Spectrum
The solar radiation spectrum
Solar constant = 1366 W/m2.

Слайд 9

Lecture # 4, Solar Astronomy
The light: particle, wave
Particle and wave
Light speed,

c = 299,792,458 m/s c ≈ 300,000 km/s
Photon energy, E = hν, ν = frequency,
h is Planck’s constant, h = 6.626 10-34 J s h = 4.135 10-15 eV s.
λ = c/ν
E = hc/λ

Слайд 10

Lecture # 4, Solar Astronomy
Electromagnetic Spectrum

Слайд 11

Lecture # 4, Solar Astronomy
Sun Spectrum

Слайд 12

Lecture # 4, Solar Astronomy
The Sun
Sun has a capacity of 3.86×1026

W 3.86×108 EJ/s
Earth gets only two-billionth part of it.
127,400,000 km² - Earth cross-section
1.740 1017 W = 0.174 EJ/s
Armenian annual energy consumption: 0.1752 Quads
Solar Constant =1366 W/sq.m.
Average Insolation = ¼ of solar const. = 342 W/sq.m.

Слайд 13

Lecture # 4, Solar Astronomy
How this energy is generated?

Слайд 14

Lecture # 4, Solar Astronomy
How this energy is generated?
About 74% of

the Sun's mass is hydrogen, 25% is helium, and the rest is made up of trace quantities of heavier elements.

Слайд 15

Lecture # 4, Solar Astronomy
How this energy is generated?
The Sun has

a surface temperature of approximately 5,500 K, giving it a white color, which, because of atmospheric scattering, appears yellow.

Слайд 16

Lecture # 4, Solar Astronomy
How this energy is generated?
The Sun diameter: 1.4

106 km = 109 that of the earth.
Distance from Earth: 1.5 108 km, = 8.31 min at light speed

Слайд 17

Lecture # 4, Solar Astronomy
How this energy is generated?
It was Albert

Einstein who provided the essential clue to the source of the Sun's energy output with his mass-energy relation: E=mc²

Слайд 18

Lecture # 4, Solar Astronomy

Слайд 19

Lecture # 4, Solar Astronomy

Слайд 20

The Sun
Lecture # 4, Solar Astronomy

Слайд 21

Lecture # 4, Solar Astronomy

Слайд 22

Lecture # 4, Solar Astronomy

Слайд 23

Lecture # 4, Solar Astronomy

Слайд 24

NASA caption: Giant magnetic loops dance on the sun’s horizon in

concert with the eruption of a solar flare—seen as a bright flash of light—in this imagery from NASA’s Solar Dynamics Observatory, captured Jan. 12-13, 2015. Image Credit: NASA/SDO

Lecture # 4, Solar Astronomy

Слайд 25

Lecture # 4, Solar Astronomy

Слайд 26

Lecture # 4, Solar Astronomy

Слайд 27

Lecture # 4, Solar Astronomy

Слайд 28

Sun surface videos
https://www.youtube.com/watch?v=ipvfwPqh3V4
https://www.youtube.com/watch?v=0WW1HN0iG0M
https://www.youtube.com/watch?v=lpzCSZ7Eerc
https://www.youtube.com/watch?v=nmDZhQAIeXM
Lecture # 4, Solar Astronomy

Слайд 29

Solar wind
The total number of particles carried away from the Sun

by the solar wind is about 1.3×1036 per second.
Thus, the total mass loss is about 4–6 billion tons per hour.
Composed of: - electrons, - protons - alpha particles

Lecture # 4, Solar Astronomy

Слайд 30

Elementary particles flow from Sun – Solar Wind http://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.htmlhttp://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.html http://www.bbc.com/news/science-environment-28690559http://www.independent.co.uk/travel/europe/watch-this-beautiful-timelapse-of-the-northern-lights-over-norway-9735690.html http://www.bbc.com/news/science-environment-28690559

https://www.youtube.com/watch?v=sBWPCvdv8Bk

Lecture # 4, Solar Astronomy

Aurora Borealis

Слайд 31

Solar Wind
Lecture # 4, Solar Astronomy

Слайд 32

Aurora Borealis
https://www.youtube.com/watch?v=hsMW7zbzsUs
https://www.youtube.com/watch?v=Vdb9IndsSXk
https://www.youtube.com/watch?v=pjgvGiEHlNs
Lecture # 4, Solar Astronomy

Слайд 33

Lecture # 4, Solar Astronomy
How this energy is generated?
In 1920 Sir

Arthur Eddington proposed that the pressures and temperatures at the core of the Sun could produce a nuclear fusion reaction that merged hydrogen into helium, resulting in a production of energy from the net change in mass.

Слайд 34

This actually corresponds to a surprisingly low rate of energy production

in the Sun's core—about 0.3 µW/cm³ (microwatts per cubic cm), or about 6 µW/kg of matter.
For comparison, the human body produces heat at approximately the rate 1.2 W/kg, roughly a million times greater per unit mass.

Lecture # 4, Solar Astronomy

Слайд 35

Lecture # 4, Solar Astronomy

Слайд 36

Lecture # 4, Solar Astronomy
How this energy is generated?
most of the

elements in the universe had been created by nuclear reactions inside stars like the Sun.

Слайд 37

Lecture # 4, Solar Astronomy
1.5 The future of energy resources
Solar Constant

= 1366 W/sq.m.
Sahara’s surface area = 9,000,000 sq.km.
If we use 10% of Sahara with 12.5% efficiency, we will get 1000 Exajoules/year!
This is twice as much as current world consumption.
I can see the future «Ocean Solar Power Plants», that produce Hydrogen!
However, population grows exponentially!

Слайд 38

Lecture # 4, Solar Astronomy

Слайд 39

Earth's rotation
Earth's rotation tilts about 23.5 degrees on its pole-to-pole

axis, relative to the plane of Earth's solar system orbit around our sun.
As the Earth orbits the sun, this creates the 47-degree peak solar altitude angle difference, and the hemisphere-specific difference between summer and winter.

Lecture # 4, Solar Astronomy

Слайд 40

Lecture # 4, Solar Astronomy

Слайд 41

Solar Constant
Lecture # 4, Solar Astronomy

Слайд 42

Now: go to the article http://www.wired.com/2015/07/pluto-new-horizons-2/
Lecture # 4, Solar Astronomy

Слайд 43

Lecture # 4, Solar Astronomy

Слайд 44

Solar radiation bouncing atmosphere
the theoretical daily-average insolation at the top of

the atmosphere, where θ is the polar angle of the Earth's orbit, and θ = 0 at the vernal equinox, and θ = 90° at the summer solstice; φ is the latitude of the Earth. The calculation assumed conditions appropriate for 2000 A.D.: a solar constant of S0 = 1367 W m−2, obliquity of ε = 23.4398°, longitude of perihelion of ϖ = 282.895°, eccentricity e = 0.016704. Contour labels (green) are in units of W m−2

Lecture # 4, Solar Astronomy

Слайд 45

Lecture # 4, Solar Astronomy

Слайд 46

Airmass
In astronomy, airmass is the optical path length through Earth's atmosphere

for light from a celestial source.
As it passes through the atmosphere, light is attenuated by scattering and absorption; the more atmosphere through which it passes, the greater the attenuation.
Consequently, celestial bodies at the horizon appear less bright than when at the zenith.

Lecture # 4, Solar Astronomy

Слайд 47

Earth Atmosphere
Lecture # 4, Solar Astronomy

Слайд 48

Rayleigh scattering
Lecture # 4, Solar Astronomy

Слайд 49

Airmass
Lecture # 4, Solar Astronomy
“Airmass” normally indicates relative airmass, the path

length relative to that at the zenith at sea level, so by definition, the sea-level airmass when the sun is at the zenith is 1.
Airmass increases as the angle between the source and the zenith increases, reaching a value of approximately 38 at the horizon.
Airmass can be less than one at an elevation greater than sea level.

Слайд 50

Airmass
Atmosphere height = 8.5 ÷ 11 km.
Earth's mean radius is 6371 km.
Airmass

abbreviation: AM##.
E.g. at angle of approximately 60 degrees over horizon we have AM2, = 62% of solar constant.
The solar panels are often rated at AM1.5
The maximum airmass at horizon is: AM35.5 ÷ AM39
At sea level, AM1 attenuates @ 27%.
At AM10 we have 23X attenuation
At AM20 we have >10000X attenuation

Lecture # 4, Solar Astronomy

Слайд 51