01 Basics cvxcvxcv

7/28/2019 01 Basics cvxcvxcv

1/45

Technische Universitt Mnchen

1. Chapter Basics

1

1. Energy demand and definition of solar thermal power

2. History of solar thermal power

3. Physics and thermodynamics

4. Measurements and solar potential

Content


2/45


1. Primary energy demand worldwide - today

0,0

2000,0

4000,0

6000,0

8000,0

10000,0

12000,0

14000,0

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010

Milliontonnesoilequ

ivalent

Source: BP Statistical Review of World Energy June 2011

2010:

12.002 Million tonnes of oil

equivalent ~ 140,000 TWh

2


3/45


1. Primary energy demand worldwide - tomorrow

0,0

2000,0

4000,0

6000,0

8000,0

10000,0

12000,0

14000,0

16000,0

18000,0

1990 1995 2000 2005 2010 2015 2020 2025 2030

Milliontonnesoilequ

ivalent

Source: BP Energy Outlook 2030: January 2011

2030:

16.432 Million tons of oil equivalent >

190,000 TWh

3


4/45


1. Solar Thermal Power Plants - What is this?

Not to be mixed with:

Solar thermal systems (flat and tubular collectors) or

photovoltaic systems

There are two types of solar thermal power plants:

Using concentrated incident solar radiation on an absorber(CSP

Concentrated Solar Power)

Without using concentrated solar radiation

4


5/45


2. History Ancient Age

1000 BC: In Central America, parabolic reflectors were used as

lighters

3rd Century BC: Greeks attacked enemy ships using concentrated

sunlight (Archimedes)

Source: independent.co.uk

1000

BC

2000

AD

500

AD

0500

BC1500

AD

1000

AD

5


6/45


2. History Ancient Age

100 AD Heron of Alexandria: Solar driven water heater

Till 400 AD, the Vestal Virgins in Rome ignited the sacred fire once

a year using a burning lense

1.000

BC

2000

AD

500

AD

0500

BC1500

AD

1000

AD

Source: archinform.net

6


7/45


2. History - Middle ages to Modern times

1.000BC

2000AD

500AD

0500BC

1500AD

1000AD

1500 200017001600 19001800

No significant developments until 1500 AD

7


8/45



In 1515, Leonardo da Vinci experimented with parabolic-mirror

concentrators to improve cloth drying

1500 200017001600 19001800

Source: culturalheritageimagin.org

8


9/45



1690: Ehrenfried Walter von Tschirnhaus developed focusing

mirrors with a diameter of 1.60 mfor experiments in porcelain

making

1772: Isaac Newton experimented with concave mirrors

1500 200017001600 19001800

9


10/45



1816: Robert Stirling developed the Stirling engine

Source: stirling.5x.to

1500 200017001600 19001800

10


11/45



Further developments in solar ovens / cookers and first

steps toward the development of solar cell

1876: William Adams wrote a book titled

SolarHeat: A Substitute for Fuel in Tropical Countries

1500 200017001600 19001800

11


12/45



1878: Augustine Mouchot introduced a solar steam generator at

the world exhibition in Paris

Source: Detail.de

1500 200017001600 19001800

12


13/45


2. History Modern times

1913: Frank Shuman: 55PS-Plant (40 kW) in Egypt (3,500 m) with

parabolic collectors. Later on, the plant was closed and destroyed.

Source:

solarhaven.org

1500 200017001600 19001800

13


14/45


Hardly any further development until the 1970s

Development during 70s to 80s was rather theoretical in nature

and hardly any plants were built.


1.000BC

2000AD

500AD

0500BC

1500AD

1000AD

1980 201020052000199519901985

14


15/45



1981 Research project Solar One, Mojave Desert, California:

10 MW- Solar tower power plant

1980 201020052000199519901985

Source: solarserver.com

15


16/45



1984: Kramer junction, Mojave Desert, California:

14 MW- First commercial CSP with parabolic trough

Expansion until today: 354 MW

Source: dlr.de

1980 201020052000199519901985

16


17/45



1997 Almera: 10 kWel- Dish-Stirling Pilot plant

1999 Solar Two (retrofit of Solar One)

Source: theirearth.com

1980 201020052000199519901985

17


18/45



2006 Andalusia: Commencement of Andasol 1:

First CSP in Europe with 50 MWel in operation since 2008

Source: Solar Millennium

1980 201020052000199519901985

18


19/45



2008: Egypt: Construction start of first CSP in Africa with 50 MWel

2009: Establishment of the DESERTEC Foundation

1980 201020052000199519901985

19


20/45


2. History Current Situation

2011, about 1.17 GWel of CSP power is installed worldwide: 582

MWel are in Spain, 507 MWel in the U.S

17 GWel of CSP projects are currently being planned worldwide:

8 GWel in USA, 4.5 GWel in Spain, 2.5 GWel in China

20


21/45



Radiation: Photon

Photon (derived from Greek: phs - "Light") is an elementary

excitation of the quantized electromagnetic field

It exhibits properties of both waves and particles

Wave-particle duality

Photons are massless (m = 0 kg)

Photons move at the speed of light

In vacuum this is 300 000 21


22/45



Radiation:

All wavelengths have the same propagation speed, in vacuum =

=

Planck's constant describes the relationship between energy and

frequency of a photon

Energy of an photon:

=

Planck's constant =6.636 10

The shorter the wavelength (or higher the frequency), the greater is

the Energy of the photon

22

Wavelength Frequency

Period []


23/45



Radiation: Spectrum

Source: Incropera, DeWitt

23


24/45


24

Absorption Reflection Transmission Emission

The absorption

coefficient

indicates

how much radiation is

absorbed

The reflectance

indicates the

relationship between

incident and reflected

radiation

The degree of

transmission

indicates the

relationship between

incident and

transmitted radiation

The emissivity

indicates how much

radiation is emitted by

the body

The value of variesbetween 0 and 1

The value of varies

between 0 and 1

The value ofvariesbetween 0 and 1

The value ofvariesbetween 0 and 1.

The darker the body,

the higher the degree

of absorption

Reflectance is strongly

dependent on the

material

Transmittance is

strongly dependent on

the material

For

mirrors = 0 and for anideal black body = 1


25/45



Interaction of radiation with matter: Reflection

Law of reflection: Angle of incidence is equal the angle of reflection

=

Both angles along with the normal of the mirror lie in the same

plane

Incident ray Reflected ray

Mirror

Normal

25


26/45



Black Body

An ideal black body absorbs all incoming radiation completely and

emits with a specific maximum intensity

The spectrum of radiation emitted by a black body depends solely

on its temperature

Absorptance = 1Emissivity = 1Reflectance

= 0

Transmissivity = 0

The sun is very close to being an ideal black body

26


27/45



Planck's law

=

1

where

=2 =3.7410 / = / = 1. 4410

= 1 . 3 8 1 0 (Boltzmann Constant)Temperature of the radiating surface T

27


28/45



Planck's law The wavelength of

maximum intensity

decreases with increasing

temperature

The higher the temperature,

the higher is this maximum

intensity

Source: Wikipedia

28

Wavelength in m

Plancks radiation spectrum


29/45



Stefan-Boltzmann law (Josef Stefan and Ludwig Boltzmann)

Specifies the thermal power emitted by an ideal black body as a

function of its temperature

= Radiation []Stefan-Boltzmann-Constant = 5 . 6 7 1 0 Surface area of the body Absolute Temperature

29


30/45



Stefan-Boltzmann law (Josef Stefan and Ludwig Boltzmann)

For a non-black body, the following equation applies:

= With the weighted average of the emissivity over the wavelengths

()

30


31/45



The Sun: General data

Almost spherical radiating source

Diameter: =1.39210 km Surface temperature: approx. 5777 K

Core Temperature: 15 Million K

The Earth: General data

Almost spherical

Diameter: =1.27110 km Surface temperature: 390 K(-89.6 CAntarctic +58 C Libya)

Core Temperature :


32/45



1/r Inverse square law for energy quantities (Solar Radiation)

Surface Power Density [W/m]

= =

1/r Inverse distance law for linear field quantities

(Acoustic quantities)

Sound pressure, Sound velocity, Sound deflection

Source: wikipedia

32


33/45



The Sun: Solar constant

The amount ofradiation that reaches the earths atmosphere

= 1 3 6 0

The actual density of the radiation outside the Earth's atmosphere

determines the average solar constant . It was standardised bythe World Meteorological Organization in 1982:

=1367 7

33


34/45



The Sun: Solar constant

Comparison between

spectral irradiance of solar

radiation(solid line) andblack body(dashed line)

34

Wavelength in m

SpectralRadiance


35/45



The Sun: Global radiation

The radiation that actually arrives on a horizontal surface on Earth

Direct solar radiation and diffused radiation

Is dependent on severe weather fluctuations

For CSP, only the direct radiation can be concentrated with opticalmethods

35


36/45


3. Physics and thermodynamics Atmosphere

Ozone (20-40 km) 0.5-3%

Upper Dust Layer (15-25 km) 1-5%

Air Molecules (0-30 km) 6-8%

Water Vapour (0-3 km) 3-9%

Lower Dust(0-3 km) 0.5-5%

0.6-4%

4%

0.4-4%

0.4-14%

Solar Radiation 1367 W/m

Direct to Earth

33-83 %

Diffuse Insolation

5-26 %

Absorbed(Lost)11-30 % Scattered into space (Lost) 1.6-11 %

Source: www.powerfromthesun.net

36


37/45



Spectral transmittances through the atmosphere

Factors influencing attenuation of solar radiation:

= , , , , ,

1. ,: Rayleigh Scattering by Molecules2. ,: Absorption by aerosols3. ,: Absorption by ozone4. ,: Absorption by Water Vapor5. , : Absorption by air

Source: Baehr, Stephan: Wrme- und Stoffbertragung

37


38/45



Sun: Intensity of Radiation

Source: renewable-energy-concepts.com

1,2,3

3 4,54

4,5

45

4

38


39/45


3. Physics and thermodynamics diurnal variations

Sun: Azimuth Angle

Deviation from the

southern orientationtowards East or West

Source: alternative-energiequellen.comAzimuth Angle

39


40/45



Sun: Angle of inclination

Deviation from the horizontal axis

Angle of inclination

40


41/45



The Sun: Azimuth and inclination

For the optimal yield of a solar system, the absorber should always

be adjusted to the Sun.

The Azimuth angle and the angle of inclination should be adapted

to the diurnal course of the Sun

For non-trackable absorber in Germany, the ideal Azimuth angle is0(South) and angle of inclination is 35

41


42/45



42

Pyranometer - Principle

Source: www.powerfromthesun.net


43/45



Global solar radiation (all the incoming solar radiation received from

above by a surface horizontal to the ground)

)

Source: meteonorm.com

Germany1200 kWh/m2aAmerica

2200 kWh/m2aSahara

2500 kWh/m2a

Spain2000 kWh/m2a

Australia2500 kWh/m2a

43


44/45



44

Direct solar radiation

Germany

1000 kWh/m2aAmerica

2700 kWh/m2aSahara

3100 kWh/m2a

Spain

2200 kWh/m2a

Australia2800 kWh/m2a

Source: meteonorm.com


45/45



01 Basics cvxcvxcv

Documents

Transcript of 01 Basics cvxcvxcv