Solar power plant
The Need
Rising electricity demand
Rapidly depleting fossil fuel reserves
Global Warming
Rising fuel imports – Loss to exchequer
Huge solar energy potential
1878- First Solar Power System Developed in France to Produce Steam to Drive Machinery
History of solar energy developments
Solar Printing Press Invented by August
Mouchat: 1878
A: Solar Collector
B: Steam Engine
C: Water Tank
Printing Press turned
By steam engine
a) Solar steam engine, Paris,1878
b) Solar steam engine, California,1901
c) Solar steam engine with flat-plate collector, Pennsylvania, 1901,1911
d) Solar steam engine, Cairo,Egypt,1913
History of solar energy developments cont…
Solar Radiation Fundamentals
Planets of the Solar System
Sun - Earth Features
Radiant energy output : 3.94 x 1026 W
Radius of the Sun : 6.960 x 108 m
Mean sun–earth distance : 149.6 x 106 Km
Radius of the Earth : 6.378 x 106 m
Energy intercepted by Earth : 1.8 x 1017 W
Solar constant : 1353 Wm-2
Solar energy is produced at the core of the
sun by nuclear fusion
The Earth's surface moves at the equator at a speed of about 467 m per second
Earth’s Rotation and Revolution
The Earth’s rotational axis is tilted 23.5° from the red line drawn perpendicular to the
ecliptic plane. This tilt remains the same anywhere along the Earth’s orbit around the
Sun. Seasons are appropriate only for the Northern Hemisphere.
Earth’s Rotational Axis Around the Sun Over the Year
Earth's axis at 0°
Late June: Northern Hemisphere
summer, Southern Hemisphere winter
Late December: Northern Hemisphere
winter, Southern Hemisphere summer
Shape of the Earth’s Orbit around the Sun
Earth’s Orbit around the Sun
During the June solstice the Earth's North Pole is tilted 23.5 degrees towards the Sun relative
to the circle of illumination. This phenomenon keeps all places above a latitude of 66.5
degrees N in 24 hours of sunlight, while locations below a latitude of 66.5 degrees S are in
darkness. The North Pole is tilted 23.5 degrees away from the Sun relative to the circle of
illumination during the December solstice. On this date, all places above a latitude of 66.5
degrees N are now in darkness, while locations below a latitude of 66.5 degrees S receive 24
hours of daylight.
Earth’s Rotational Axis Around the Sun Over the Year – Contd…
During the equinoxes, the axis of the Earth is not tilted toward or away from the Sun and
the circle of illumination cuts through the poles. This situation does not suggest that the
23.5 degree tilt of the Earth no longer exists.
Earth’s Rotational Axis Around the Sun Over the Year – Contd…
Annual variations in day length for locations
at the equator, 30°, 50°, 60°, and 70° North latitude
Annual Variations in Day Length
Solar Radiation Budget
The radiation from the Sun, travels in the space as electromagnetic wave
The Earth receives 1.8 x 1017 W of incoming solar radiation continuously at top of its
atmosphere.
But only half of it reaches the earths’ surface.
Absorption, scattering and reflection of light during its passage through the
atmosphere are responsible for reduction of the amount of solar radiation available on
the earth’s surface
Solar energy is by nature, a low density energy source
Above the earth’s atmosphere, sunlight carries 1353 W/m2
Solar Constant
Solar constant as the amount of solar radiation received outside the earth’s atmosphere
on a unit area perpendicular to the rays of the sun, at the mean distance of the earth
from the sun.
Extraterrestrial Solar Radiation
The earth’s orbit is slightly elliptical, the intensity of solar radiation received outside the earth’s
atmosphere varies slightly from constant value by ±3.4 percent
3601 0.034cos
365.25o sc
NI I
Io = Extraterrestrial solar radiation outside
the earth’s atmosphere
N = nth day of the year
Concept of Extraterrestrial
Horizontal Irradiance
Io,h = Io Cosθz
Extraterrestrial solar radiation falling on a surface
parallel to the ground is
Isc = Solar constant, is the rate at which energy
received from the sun on a unit area perpendicular
to the rays of the sun at mean distance of the earth
from sun
Isc=1353 W/m2
Terrestrial Solar Radiation
Solar radiation falling on the earth surface is called terrestrial radiation
Terrestrial radiation varies because-
-Daily due to Earth rotation
-Seasonally due to changes in the sun declination angle
-Other effects due to presence of the various gases, vapors and particulate
matter in the earth atmosphere
The extraterrestrial radiation is attenuated by: Scattering and absorption
Scattering: a mechanism by which the part of radiation scattered laterally by air
molecules, water vapor, and dust in the atmosphere
Depends upon: scattering medium and wavelength of the radiation
Absorption: Absorption of solar radiation in the atmosphere is mainly by
- ozone O3 (-ultraviolet- short wavelength below 0.29 μm)
- water vapor H2O (Infrared- longer wavelength of spectrum at 1.0,1.4 and 1.8
μm and
- Carbon dioxide CO2 ( spectrum of 2.36 to 3.02 μm , 4.01 to 4.08 μm and
12.5 to 16.5 μm
Nominal range of clear sky
absorption and scattering of
incident solar energy
Terrestrial Solar Irradiance – Contd…
Terrestrial Solar Radiation
Solar radiation passes through the earth's atmosphere, is composed of two parts
beam and diffused radiation
Beam Radiation
Beam radiation is the solar radiation propagating along the line joining the
receiving surface and the sun
Diffuse Radiation
It is the solar radiation scattered by aerosols, dust and air molecules. It does
not have unique direction
The solar radiation received from the sun after under going scattering by the
atmosphere is known as diffuse radiation
Global Radiation
It is the sum of beam and diffuse radiation
Terrestrial Solar Radiation
Air mass (ma) : ratio of the optical thickness of the atmosphere through which
beam radiation passes to the surface to its optical thickness if
the sun were at zenith i.e direct above
ma= 0 mean extraterrestrial
ma= 1 when sun is at zenith
ma= 2 for zenith angle θz= 60o
The air mass ma is related to zenith angle
θz= 0o to θz= 70o , at sea level , by
ma= (cosθz)-1
Clearness index (Ci) : ratio of the average radiation on a horizontal surface for given
period to the average extraterrestrial radiation for same period
The averaging could be monthly, daily or hourly,
Ci would be monthly, daily or hourly clearness index
Ci varies from 30 to as high as 70 %, in some places it is zero because of bad weather
Radiation Terminology
Irradiance
The rate at which radiant energy is incident on a surface per unit area of the surface
Irradiation
The incident energy per unit area on a surface found by integration of irradiance over a
specified time, usually an hour or a day
Radiosity
The rate at which radiant energy leaves a surface per unit area, by combined emission,
reflection and transmission
Emissive Power
The rate at which radiant energy leaves a surface per unit area, by emission only
Earth Albedo
The earth reflects about 30% of all incoming solar radiation back to extraterrestrial region
through atmosphere
Parameter Instruments used
Direct solar irradiance Pyrheliometers
Global solar irradiance Pyranometer
Diffuse solar irradiance Pyranometer with shading ring
Duration of brightness Sunshine recorder
Radiation Measurements
1. Thermopile sensor 2, 3. Glass domes 4. Radiation screen
5. Signal cable 6. Gland 7. Leveling feet
8. Printed circuit board 9. Desiccant 10, 11. Level
Pyranometer – Global & Diffuse Radiation
Measures solar irradiance from 300-4000 nm
Sensor: Blackened copper constantan thermopile covered with two concentric glass
domes which are transparent to radiation from 300-4000 nm.
Generated EMF (electromotive force) by thermopile is proportional to incident
radiation.
Used for instantaneous measurement and continuous recording of Global, Diffused,
Reflected Solar irradiance.
Pyranometer – Global & Diffuse Radiation
Pyrheliometer – Beam Radiation
Measures direct solar irradiance from 300-4000 nm at normal incidence.
Sensor: Blackened copper constantan thermopile.
Sensor mounted in a long metallic tube to collimate the incident beam.
Solar tracker maintains the pyrheliometer always directed towards the sun.
Generated emf by the thermopile is proportional to incident irradiance
Used for instantaneous measurements and continuous recording of direct solar irradiance.
Pyrheliometer – Beam Radiation
Sunshine Recorder
Invented by John Francis Campbell in 1853 and later modified in 1879 by George
Gabriel Stokes
Campbell-Stokes recorder adapted for use in
polar regions
Campbell-Stokes recorder used in a Tropical region
Sunshine card for the Campbell-Stokes recorder
Nature of the solar resource
Nature of the solar resource
Sun-Earth Angles
Latitude (Ф)
The latitude of the location is the angle made by the radial line, joining the given
location to the centre of the earth, with its projection on the equatorial plane.
Declination ( )
The declination is the between the earth’s axis of rotation and the surface of a cylinder
through the earth’s orbit
= Declination
n = day number (number of
days since 1st January)
28423.45sin 360
365
n
It is defined as the angular displacement of the sun east or west of
the local meridian, due to the rotation of the earth on its axis at 15o
per hour.
W = (ST-12) x 15
ST = Local solar time
Hour Angle (w)
Nature of the solar resource
Sun-Earth Angles- Hour Angle
Nature of the solar resource
Sun-Earth Angles
z
s
s
N
S E
W
Zenith
Nature of the solar resource
Sun-Earth Angles
Zenith angle (z ): the angle between the vertical (zenith) and the line of the sun
Solar attitude angle (as): the angle between the horizontal and the line to the sun
Solar azimuth angle (s ) :the angle of the projection of beam radiation on the horizontal plane (with
zero due south, east negative and west positive)
z
s
s
N
S E
W
Zenith
Z = Zenith Angle
= Latitude
= Declination
w = Hour angle
s = Solar azimuth
angle
s = Solar attitude
angle
Nature of the solar resource
Sun-Earth Angles
cos cos cos cos sin sinz w
sin cos cos sin sincos
coss
s
w
Note:
& w should be the same sign
z
s
s
N
S E
W
Zenith
ws = Sunset angle
= Declination
= Latitude
Note:
Day length is in hours
Nature of the solar resource
Solar geometry: Sun angles: Sunset angle and day length
cos tan tansw
12Day length cos tan tan
15
Nature of the solar resource
Solar geometry: Collector angles
z
s
s
N
S E
W
Zenith
Slope: The angle between the plane of the collector and the horizontal
Surface azimuth angle: The deviation of the projection on a horizontal plane of the normal to the
collector from the local meridian (with zero due south, east negative and west positive)
Angle of incidence : The angle between the beam radiation on the collector and the normal
Nature of the solar resource
Solar geometry: Collector angles
cos sin sin cos cos sin cos
cos cos cos cos sin sin cos
cos sin sin sin
w
w
= Angle of incidence
= Surface azimuth
angle
= Collector slope
= Declination
= Latitude
w = Hour angle
Incident angles
z
s
s
N
South E
W
Zenith
Empirical Equations for Predicting the Availability of Solar Radiation
Monthly Average Daily Global Radiation
max
g
c
H Sa b
H S
gH
cH
S
maxS
a, b Constants obtained by fitting data
Monthly average of the daily global radiation on a horizontal surface at a location (kJ/m2-day)
Monthly average of the daily global radiation on a horizontal surface at the same location on a clear day (kJ/m2-day)
Monthly average of sunshine hours per day at the location (h)
Monthly average of the maximum possible sunshine hours per day at the location (h)
max
g
c
H Sa b
H S
In above equation Hc is replaced by Ho
Empirical Equations for Predicting the Availability of Solar Radiation
Monthly Average Daily Global Radiation
3601 0.034cos
365.25o sc
NI I
Empirical Equations for Predicting the Availability of Solar Radiation
Monthly Average Hourly Global Radiation
0
cosg o
g
IIa b w
H H
gI
oI
a 0.409+0.5016 sin(ws-60o)
b 0.6609 – 0.4767 sin(ws-60o)
Monthly average of the hourly extra-terrestrial radiation on a horizontal surface (kJ/m2h)
Monthly average of the hourly global radiation on a horizontal surface (kJ/m2-h)
– Contd…
Sun-Earth Angles – Contd…
Tilt Factor or Geometric Factor (R)
It is defined as the ratio of radiation flux on a tilted surface to that radiation flux falling on a
horizontal surface
BIR
I
IB Radiation at tilted surface
I radiation at horizontal surface
1 cos 1 cos
.2 2
B b b d b d gI I R I I I
bBb
b
IR
I dB
d
d
IR
I
where
z
s
s
N
S E
W
Zenith
Solar-electric conversion systems
Solar energy may be converted to electricity by one of the means:
Solar thermal conversion or photovoltaic conversion
Solar Thermal Conversion
Solar thermal
collector/
concentrator and
receiver
Hot
working
fluid
Thermal Energy
Storage system
Heating/cooling
application
Power
generation
Fluid let off
(Open Cycle)
Circulation of condensed working
fluid (Closed loop)
Radiation from SUN
Typical Solar Thermal Power Plant
Similar to a steam power plant without the “fossil-fuel” boiler
Solar Thermal
Gathering Array
Cooling Tower
Steam
Turbine Electric
Generator
Condenser
High Pressure
Pump
Hotwell
To Grid
Cooling
Water
Steam
Dryer
Water
Steam
Steam
Sun
The Rankine cycle uses a liquid that evaporates when heated and
expands to produce work, such as turning a turbine, which when
connected to a generator, produces electricity
The working fluid most commonly used is water, though other
liquids can also be used
Options to integrate solar energy into the power plant cycle:
- Steam Rankine cycle
- Organic Rankine cycle
- Brayton cycle
- Combined cycle
-Repowering systems
Power Plant Cycle
Types of Solar Thermal Power Plants
Concentrating type
Line Focusing
- Parabolic Trough
- Compact Linear Fresnel Reflector
Point Focusing
- Dish Stirling Systems / Concentrating Dish
- Solar Tower Plants using Central Receiver
Non-concentrating type
- Solar Updraft Tower: Solar Chimney
- Solar Pond
Central Receiver Solar Thermal Power Plants
Components
Heliostat
Tower
Central receiver
Turbine-generator
Storage
Condenser
Cooling tower
Central receiver has a circular field array of heliostats to focus sunlight on to a
central receiver mounted on top of a tower.
Hot salt Cold salt
Heliostat
Conventional EPGS
Hot fluid
Cold fluid
Central Receiver
Heliostat
Heliostat composed:
Reflecting surface or mirror
Mirror support structure
Pedestal
Foundation
Control and drive mechanism
Heliostat Field
Energy losses
Shadowing
Blocking
Reflective loss
Attenuation
Cosine loss
Types of field
Surrounded field
North field
Cosine Losses of Heliostat Field
Reflecting surface of the heliostat is not perpendicular to the beam radiation
Area of the solar flux intercepted by the heliostat is less than by cosine of the angle
between the surface and the perpendicular to the beam
Sun rays
Sun rays
Receiver
Surface normal z
r
B A
South field North field
Heliostat B Heliostat A
Heliostat Field
Receiver
Losses
Spillage
Reflection
Convection
Radiation
Conduction
Solar Thermal Power Solar Thermal Energy
PS10 and PS20 solar power tower (HFC)
(Seville, Spain). 2007 and 2009
Solar Power Tower One and Two
Solar Parabolic Dish Collector
Principle of Solar Parabolic Dish Collector
Solar parabolic dish collector is a Three dimensional (3-D) collector.
Array of parabolic mirrors focus solar radiation on to the receiver.
Fluid in the receiver is heated up to 1500oC and it is used to generate the electricity.
The engine under consideration include Stirling and Brayton cycle engines.
Parabolic Dish Collector
Solar Radiation heats fluid medium or drives chemical reaction
Features Solar Parabolic Dish Technology
Mature and Cost Effective Technology: Large utility projects using parabolic dishes are now
under development.
Technical Challenges
Development of solar materials and components
Commercial availability of a solar Stirling engine
Advantages
Demonstrated highest solar-to-electric conversion efficiency
Modular - may be deployed individually for remote applications or grouped together
for small-grid (village power) systems.
Solar dish-engine systems are being developed for use in emerging global markets for distributed
generation, green power, remote power, and grid-connected applications.
Individual units, ranging in size from 9 to 25 kilowatts, can operate independent of power grids in
remote sunny locations to pump water or to provide electricity for people living in remote areas.
Largely because of their high efficiency and “conventional” construction, the cost of dish-engine
systems is expected to compete in distributed markets.
Parabolic Dish Collector System at Sandia National Laboratory
Solar Parabolic Trough Collector
Principles of Solar Parabolic Trough Collector
Parabolic trough collector has a linear parabolic-shaped reflector that focuses the sun’s direct
beam radiation on a linear receiver located at the focus of the parabola.
The collectors track the sun from east to west during the day
Heat transfer fluid is circulated through the receiver and returns to a series of heat exchangers
in the power block where the fluid is used to generate high-pressure superheated steam.
The superheated steam is then fed to a conventional reheat steam turbine/generator to produce
electricity.
Parabolic Trough (Contd..)
Parabolic Trough (Contd..)
High optical and tracking accuracy
Low heat losses
Manufacturing simplicity
Reduced weight and cost
Increased torsional and bending stiffness under wind loads
Reduced number of parts
Corrosion resistance
More compact transport methods
Reduced field erection costs, without loss of optical accuracy
Increased aperture area (reduced drive, control and power requirements per unit
reflector area)
Features of Solar Parabolic Trough Collector
The Rankine cycle system uses a liquid that evaporates when heated and expands to
produce work, such as turning a turbine, which when connected to a generator, produces
electricity.
The working fluid most commonly used as water, though other liquids can also be used
Number of Rankine power cycles can be used for parabolic trough power plants and
there are a number of options for how to integrate solar energy into the power cycle.
Steam Rankine cycle
Organic Rankine cycle
Combined cycle
Power Cycle
Steam Rankine Cycle
The SEGS (solar electric generating system) plants and most new projects are planning
to use steam Rankine power cycles. These power plants have power cycles very similar
to those used for coal, nuclear, and natural gas-fired steam power plants.
The 80-MWe SEGS plants use a regenerative reheat steam turbine cycle that has a gross
steam cycle efficiency approaching 38% with high-pressure steam conditions of 100bar,
and 370°C.
The power cycle uses a solar steam generator in place of the conventional boiler
The power cycle also consists of
- A surface condenser
- Feed water heaters
- Deaerator
- Cooling towers
Solar energy is used to generate the high-pressure steam and also to reheat the steam
The solar field supplies the hot heat transfer fluid (HTF) to the power plant
The heat transfer fluid passes through a series of shell-in-tube heat exchangers
to generate the high-pressure steam that runs the Rankine steam turbine.
The cold heat transfer fluid is then returned to the solar field.
Steam Rankine cycle
1
2 3
4 1
Direct Steam Generation
The parabolic trough plants can generate steam directly in the solar field.
This eliminates the need for an intermediate heat transfer fluid and steam generation heat
exchangers.
It will allow the solar field to operate at higher temperatures, resulting in higher power
cycle efficiencies
The direct steam generation is still one of the most promising opportunities for future cost
reductions.
Control Scheme for Direct Steam Generation
Once through concept
Recirculation concept
Injection concept
In direct steam generation the changes in the inlet water conditions and/or solar radiation
will only affect the amount and quality of steam produced by the solar field.
Control Scheme for Direct Steam Generation – Contd…
Different Control Scheme for Direct steam generation
Once through mode
The main disadvantages is, the controllability of the superheated steam parameters at the
collector field outlet
Recirculation mode
The measurement system necessary to assist the control scheme
Injection mode
The amount of water fed at the inlet of the evaporator is greater than the amount
that can be evaporated.
The steam produced is separated from the water by the middle separator and is
fed into the inlet of the super heater section.
This type of DSG system is highly controllable
The middle water–steam separator and the water recirculation pump increase the
system load.
Parabolic Trough -Contd..
Solar Thermal Energy
Solar Thermal Power
Andasol solar power station (PTC)
(Granada, Spain), 2009
Puertollano solar power station (PTC)
(Ciudad real, Spain), 2009
Linear Fresnel Reflector (LFR)
Linear Fresnel Reflector (LFR) is a single-axis tracking technology that focuses sunlight reflected by
long heliostats onto a linear receiver to convert solar energy to heat , using array of mirror strips
close to the ground to direct solar radiation to a single, linear, elevated, fixed receiver
Linear Fresnel Reflector (LFR)
Features of Compact Linear Fresnel Reflector
Inexpensive planar mirrors and simple tracking system
Fixed absorber tube with no need for flexible high pressure joints or thermal expansion
bellows
No vacuum technology and no metal-to-glass sealing
Wind loads are substantially reduced on the reflector strips, so the reflector width for one
absorber tube can be up to three times the width of parabolic troughs
Efficient use of land since the collectors can be placed close to one another
It weighs as little as 3 kg per sq meter, 30% of the weight of the parabolic trough mirror
Technical Details of Liddell Power Plant The reflector rows are 600 m long and 1.6 m wide, and composed of reflector space frame
modules that are 10 m long
Excellent ground utilisation is achieved with at least 62% ground coverage
The towers are 7.5 m high at the receiver aperture
The array uses flat or curved reflectors instead of costly sagged glass reflectors
The reflectors are of low cost 3mm mirrored glass, with a reflectance of 0.83 and are mounted close to the ground
Low cost demineralised water is used as the heat transfer fluid
Liddell CLFR system will provide 95 MW of thermal energy to the power plant, giving an estimated electrical equivalent of 35 MWe
Prototype array Receiver with tubes
Liddell Power Plant – Different Views
Solar Thermal Power
Solar Thermal Energy
Calasparra solar power plant (LFR)
(Murcia, Spain) 2009.
Solar Thermal Power
Types of solar thermal power plant
Technology roadmap concentrating solar power, IEA, 2010.
Solar pond
Non-concentrating Solar Thermal Power Plants
92 Non-concentrating Solar Thermal Power Plants
Solar Pond
Non-concentrating Solar Thermal Power Plants
Solar Pond (Contd..)
A Solar Pond collects solar energy by absorbing both the direct and
diffuse components of sunlight
A solar pond is a reservoir of salty water that stores solar heat and uses
this heat for power generation or other applications
Solar pond contains salt in high concentrations near the bottom, with
significantly diminishing concentrations near the surface. This salt-
density gradient is obtained by perfectly dissolving heavy salt with the
increasing depth to suppress the natural tendency for heated fluid to rise
to the surface and lose its heat to the atmosphere by evaporation,
convection, and radiation
The density gradient permits heated fluid to remain in the bottom layers of
the pond while the surface layers are sufficient to drive the vapour
generator of an organic Rankine-cycle engine, to provide process heat and
to desalt water temperatures of about 90°C are commonly attained in the
pond bottom
Non-concentrating Solar Thermal Power Plants
Solar Pond (Contd..)
Solar Pond (Contd..)
nmas
Solar Pond (Contd..)
Solar Pond (Contd..)
Operating difficulties
Effect of the diffusion on concentration profile
Surface layer flow and lower layer flow
Wind induced wave
Biological growth
Fouling due dirt and leaves
Solar Chimney
Non-concentrating Solar Thermal Power Plants
Non-concentrating Solar Thermal Power Plants
Solar Chimney
Non-concentrating Solar Thermal Power Plants
Solar Chimney (Contd..)
A solar chimney power plant has a long tower, with a height of up to 1000 m,
and this is surrounded by a large collector roof, up to 130 m in diameter, that
consists of glass or resistive plastic supported on a framework
The sun heats up the ground and the air underneath the collector roof, and the
heated air follows the upward incline of the roof until it reaches the chimney
Heated air flows at high speed through the chimney and drives wind generators
at its bottom
The ground under the collector roof behaves as a storage medium, and can even
heat up the air for a significant time after sunset
The efficiency of the solar chimney power plant is below 2%, and depends
mainly on the height of the tower, and so these power plants can only be
constructed on land which is very cheap or free
Working principles of Solar Chimney
Transparent roof, which admits the short wave solar radiation component and retains long-wave radiation from the heated ground.
Thus, when solar radiation pass through the transparent roof it is absorbed by the ground elements and it converts into heat energy.
Transparent roof
•Since air is heated, it starts to
rise up and move towards to
chimney,seen in fıgure 11.
Also, it gains velocity.
•Heated air enters the chimney
placed at the center of the roof
and creates an up draught there.
•Inside the chimney, turbines
with electric generator, produce
electricity .
Working principles of Solar Chimney
Prototype of the solar chimney at Manzanares.
chimney 195 m high
and 10 m in diameter
surrounded by a collector 240 m
in diameter.
Heat Output
Collector Area Solar Radiation
Specific heat
capacity of the air
Mass flow
Collector Efficiency
The temperature
differences between the
collector and out flow
Air speed at collector
outflow Specific density of air at
temperature To + ΔT at collector
outflow
Chimney cross-section area
The sheet metal was only 1.5mm
thick
150m high
10m diameter
The sheets were abuted vertically at
intervals of 8.6m and shiftened every
4m by exterior trussrirelers
Solar Chimney Prototype at Manzanares (Spain)
Solar Chimney Prototype at Manzanares
Solar Chimney (Contd..)
Non-concentrating Solar Thermal Power Plants
Solar Radiation Budget – Contd…