Prof. (Dr.) H.P. Garg
Formerly
Professor & Head
Centre for Energy Studies
Indian Institute of technology, Hauz Khas,
New Delhi-110016, India
Mob. +91-98180 00984
E-mail: [email protected]
SOLAR ENERGY
The SUN
Source of
all Energy
Produces
Energy
from H2
4H1 →He4 + 2+ + 2 + 25 MeV
E = mc2
• The atmosphere absorbs extraterrestrial radiation at certain wavelengths, resulting in an altered spectral distribution for terrestrial radiation.
Terrestrial solar spectrumTerrestrial solar spectrum
SOLAR RADIATION RESOURSE ASSESSMENT STATION
A pyranometer measures total global solar irradiance from the whole sky.
Eppley Precision Pyranometer
Global radiation availability in India
SOLAR THERMALFor direct heating , cooking, drying and power generation etc.
SOLAR PHOTOVOLTAICFor direct electricity generation
Solar Energy
Solar energy can be used through two main routes
Uses of Solar Energy Heating of Water
Heating of Houses (active systems)
Distillation of Water
Cooking of Food
Greenhouse Heating
Drying of Food
Power Generation
Refrigeration and Airconditioning
Passive Heating and Cooling
Production of Very High Temperatures
Industrial Process Heat Systems
Pumping of Water
Direct Conversion of Electricity (PV)
National Renewable Energy
Laboratory
Innovation for Our Energy
Future
Evacuate Tube Collector
Flat Plate Collector
Solar Pond
Parabolic Trough Collector
Linear Fresnel Reflector
Power Tower (Heliostat)
Parabolic Dish
Solar Collectors
Solar Collectors
Schematic cross-section of a typical flat plate solar collector
illustrating the major functional parts
Principle of an evacuated tube collector with heat pipe; view from top
Asia’s largest solar pond of 6000 m2 area at Bhuj, Gujarat
Solar Concentrators• Solar concentrators are optical devices which increase the flux
on the absorber surface as compared to the flux incident on theconcentrator aperture. Optical concentration is achieved by theuse of reflecting or refracting elements positioned toconcentrate the incident flux onto a desired absorber surface.
• A solar concentrator usually consists of (i) an optical device tofocus solar radiation (ii) a blackened metaliic absorber providedwith a transparent cover, and (iii) a tracking device forcontinuously following the sun.
• Temperatures as high as 3000C can be achieved with suchdevices and they find applications in both photothermal andphotovoltaic conversion of solar energy.
Solar Concentrators
SSSSSSOLAR POWER GENERATION IN INDIASSSSSPARABOLIC TROUGHS
Linear Fresnel Reflector
CENTRAL TOWER
SSSSSSOLAR POWER GENERATION IN INDIASSSSSPARABOLIC DISH
3500 °C
1500 °C
400 °C
150 °C
50 °C
Paraboloid Dish
Solar Tower
(Central Receiver System)
Parabolic Trough /
Linear Fresnel
Temperature Levels of CSP TechnologiesTemperature Levels of CSP Technologies
Schematic diagram of a Thermosyphon solar water heater
Auxiliary
Storage
tank
Hot water
outlet
Cold
water
inlet
Auxiliary Heater
Solar Water Heating System
Hot water at 60-80 oC for hotels,hospitals, restaurants, dairies,industry and domestic use
System comprises one or morecollectors, storage tank, piping etc.Heat exchanger and pumps added, ifnecessary
About 8.90 million sq.m. collectorarea installed
BIS standard for collectorsintroduced in 1990/1992. Standardsupdated recently
60 BIS approved manufacturers withproduction capacity of over 300,000sq. m. collector area per annum
Solar Cookers
• Solar cookers are used and developedin several countries including India.
• In India all the three types of solarcookers like box type, reflector type (SKtype) and large size (Scheffler type) arein use.
• Typical box type solar cooker takes 2-2.5 hours for cooking of food and is60x60x17 cm in size.
• Parabolic domestic solar cooker (SK-14)with reflector diameter 140 cm givesabout 200C temperature and cooksfood for 8-10 persons at a time.
• Scheffler community solar cooker withsingle or multiple dish (each of about 10m2 reflector) is suitable for communityuse and one such solar cooker forcooking meal for 15000 people is in useat tirupati, A.P with total reflector area of1000 m2.
World's Largest Solar Steam Cooking System at
Tirupati, Andhra Pradesh
Location
• Installed at the temple town of Tirumala, Andhra Pradesh with nearly 50 percent funding from MNES
System
• Employs automatic tracking solar dish concentrators to convert water In to high pressure steam which Is used for cooking purpose* In the community kitchen.
Technical Details
• Solar dish concentrators (106 Nos) with total reflector area of about 1000m2.
• Modular in nature and consists of several units (parallel & series) connected to central pipe-line system.
• Each dish consists of scheffler mirrors with an aperture area of 9.4 sq.m.
• Generates 4,000 kg of steam per day at 180°C and 10 Kg/cm2.
• Cook meals for around 15,000 persons per day.
• The cooker saves about 1,20,000 litres of diesel per year.
• The total cost of the system Is about Rs. 110 lakh.
Implementing Agency
• Ministry of Non-Conventional Energy Sources (MNRE).
CLASSIFICATION OF SOLAR DRYERS
DIRECT TYPE DRYERS : In direct or natural convection typ dryers,the agricultural product is placed in shallow layers in a blackenedenclosure with a transparent cover. The solar radiations are directlyabseorbed by the product itself. The food product is heated up andthe moisture from the product evaporates and goes out by thenatural convection.
INDIRECT TYPE DRYERS : In these dryers the food product isplaced in a drying chamber. The air is heated in solar air heatersand then blown through the drying chamber. In some of the designs,dryers receive direct solar radiations and also heated air from solarair heaters. In these dryers manipulation of temperature, humidityand drying rate is possible to some extent.
FORCED CIRCULATION TYPE DRYERS : In these dryers, hot airis continuously blown over the food product. The food product itselfis loaded or unload continuously or periodically. These kind ofdryers are comparatively thermodynamically efficient, faster and canbe used for drying large agricultural product. These dryers can be ofCross-flow type, concurrent flow type or counter-flow type.
(c) Forced circulation type solar dryers
(a) Direct type solar dryers
(b) Indirect type solar dryers
TYPE OF SOLAR DRYERS
Photograph of Solar
Cabinet Dryer
SOLAR DESALINATION TECHNIQUES
Potable Water Less than 550 ppm
Requirement Domestic, Industries and
Agriculture
Sources of Potable
Water
Rivers, Lakes, Ponds, Wells etc.
Demand of Potable
Water
15-25 litres / person / day (OLD)
100-125 litres / person / day
(NEW)
Underground Saline
Water
2,000 – 2,500 ppm
Sea Water 30,000 – 50,000 ppm
Double sloped experimental solar still
Multi-effect Solar Distillation System
Photograph of the multi effect H-D Solar Distillation unit at IIT Delhi
There are several ways of using solar energy for cooling such as:
• Using the absorption cycle with liquid absorbents such as LiBr – H2O, NH3, LiCI – H2O, NH3 – LinNO3, R22 – DMF, NH3 – NaSCN.
• Using the absorption cycle with solid absorbents such as: CaCl2 - NH3
• Using adsorption cycle with solid absorbents such as: Silicagel H2O, Zeolites –H2O.
• Using the vapor compression cycle employing a solar powered Rankine engine.
• Using the vapor compression .cycle with the compressor driven by electricity from photovoltaic panels.
• Nocturnal passive cooling.
Several prototype systems based on some of the above principles have already been made and demonstrated but these are still under development to be dependable and commercial. The choice of a particular system not only depends on its economics but also on local factors such as climate, availability of cooling water, auxiliary energy source, and the type of collector available.
Solar Refrigeration and Air conditioning
Photograph of intermittent absorption
refrigerator developed at IIT Delhi
100 kW Solar Cooling System
• Heat source : Hot water from solar collectors
• Hot water temperature : 210°C• Cooling capacity : 100 kW
• Chilled water Temperature: 12 / 7 Deg C.
• Cooling water inlet Temperature : 32 Deg C
• COP of cooling system : 1.7
• Thermal storage : Chilled water / Hot water / PCM for short duration
Solar-passive building design addresses indoor
thermal comfort as well as visual comfort
Solar-passive
building design
Thermal
ComfortVisual Comfort
Reduce energy
demand of space-
conditioning
Reduce energy
demand of
artificial lighting
Reduction in energy consumption and GHG
emission
PASSIVE HOUSE CONCEPTS AND STANDARDS
Go Green
Best Building Form
Solar & Energy Efficient Design
Improved Indoor Air Quality
Usage of Green Materials
Proper Mechanical Systems
Efficient Lighting
Proper Testing & Maintenance
Go Green
Indira Paryavaran Bhawan
•Total Plinth Area is 30,914 sq.mtrs • Platinum Rating as per LEED India & 5 star Rating by GRIHA
Solar Thermal Power Generation
Present Status-Renewable EnergyTotal Installed capacity 31,707 MW
Parabolic Trough Concentrator
Parabolic-trough and solar tower plants are the most developed
concentrating solar power (CSP) technologies realized up to date,
with more than 500 MW of commercial plants operating.
Parabolic Trough Concentrator
Proven Technology: SEGS plants
SEGS: Solar Electric Generating System
9 plants at three locations (Daggett, Kramer Junction, Harper Lake), Mojave desert (CA)
Individual unit size: 14 to 80 MWe
Installed between 1984 and 1990
Total size: 354 Mwe
Still operating: actual operator of units III to IX is FPL Energy; electricity customer is SCE
Proven Technology: SEGS plants
SEGS: Solar Electric Generating System
Solar Central Tower – Heleostat Systems
Always at an angle,
depending on Latitude, season
and Position of heleostats
SSSSSSOLAR POWER GENERATION IN INDIASSSSSSSSSSSOLAR POWER GENERATION IN INDIASSSSS
SSSSSSOLAR POWER GENERATION IN INDIASSSSSSolar Central Tower – Heleostat Systems
Constructed: Only pilot plants (approx. 15 MWe)
Under construction/
development:
Spain:
approx. 500 MWe
in total
Greece:
approx. 50 MWe
Heleostats-Central Tower CSP plants in Europe
Solar Technologies :Thermal
• Sterling engine is external combustion engine
• Therefore fuel flexible
• Highly efficient- about 40%
• With high efficiency paraboloidal dish (85%), overall eff.- > 30%
• The present available unit size: 25 kW
• MW size plants use a no. of these modular units
• Can be hybridized with biomass gasification unit to supply 24 x 7 power
• Rugged
• Good option for rural applications
Solar Dish Sterling Engine
Dish stirling
Stiriling EngineStiriling Engine
SOLAR FIELD
• Solar Collector Assembly – 480
• Aperture (m) – 5.71
• Aperture area (m2) – 871.5
• Length (m) – 150
• Optical Efficiency – 77%
• # of mirror segments – 1,61,280
• # of Receiver Tubes – 17,280
• Field Aperture area (m2) – 3,92,400
• Site Area (acres) – 400
• Solar field inlet temperature (OC) – 293
• Solar Field outlet temperature (OC) – 393
POWER BLOCK
• Turbine Generator Gross output – 55 MWe
• Net Output to Grid – 50 MWe
• Solar Steam Inlet Pressure – 98 bars
• Solar Steam Reheat Pressure – 19 bars
• Solar Steam Temperature – 385OC
India’s First 50 MW CSP Plant at JaisalmerCSP Plant Characteristics
National Solar Thermal Power Testing ,Simulation
& Research Facility at NISE
© 2011 KPMG Advisory Services Private Limited, the KPMG India member firm of KPMG International, a Swiss cooperative. All rights reserved. KPMG and the KPMG
logo are registered trademarks of KPMG International, a Swiss cooperative.
Solar cells, the heart of a PV system, are meant to absorb
sunlight and convert it directly to electricity. These are made
from a wide range of semiconductor materials.
For best solar energy conversion the optimum band gap is ~
1.1 - 1.5 eV.
Some of the best solar cell materials are: Silicon (1.12 eV),
InP (1.40 eV), GaAs (1.42 eV), CdTe (~1.44 eV) and CuInSe2
(~1.0 eV).
Energy of the incident photons produce electron-hole pairs
that are separated by the electric field and give rise to
unidirectional electric current.
These are collected by the external contacts at the two faces
of the semiconductor and produce usable DC power.
PHYSICS OF SOLAR CELLS
© 2011 KPMG Advisory Services Private Limited, the KPMG India member firm of KPMG International, a Swiss cooperative. All rights reserved. KPMG and the KPMG
logo are registered trademarks of KPMG International, a Swiss cooperative.
Si has 04 electrons in valence bond
n-type: Doping with Phosphorous (5 electrons)
p-type: Doping with Boron (3 electrons)
One –way Flow or Diode Effect: The Photovoltaic Effect
Solar Technologies :PV
Electrical circuitry is produced on both sides-
Bottom thin metal plates; Top- Silver grid
Solar Photovoltaics
Crystalline silicon solar cells: mono crystalline silicon (c-Si) andmulticrystalline silicon (mc-Si)
Surface barrier solar cells (a-Si on c-Si) – Passivated Interface (PI) at heterojunction
Thin film solar cells:
amorphous silicon (a-Si)
polycrystalline copper indium diselenide (CIS) or
copper-indium-gallium - selenide / sulphide (CIGS)
cadmium telluride (CdTe)
thin-film crystalline silicon
Gallium arsenide (GaAs) and multi junction cells (GaInP / GaAs / Ge ) with super-high efficiency
Nano crystalline Dye-sensitized TiO2 based and other nano-structured solar cells
Organic (Polymer) solar cells
TYPES OF SOLAR CELLS
Types of solar cells based on choice of semiconductor material
and device structure
© 2011 KPMG Advisory Services Private Limited, the KPMG India member firm of KPMG International, a Swiss cooperative. All rights reserved. KPMG and the KPMG
logo are registered trademarks of KPMG International, a Swiss cooperative.
Solar Cell Best Efficiencies: World
© 2011 KPMG Advisory Services Private Limited, the KPMG India member firm of KPMG International, a Swiss cooperative. All rights reserved. KPMG and the KPMG
logo are registered trademarks of KPMG International, a Swiss cooperative.
First Generation
• Single crystal silicon wafers (c-Si)
Second Generation
• Amorphous silicon (a-Si)
• Polycrystalline silicon (poly-Si)
• Cadmium telluride (CdTe)
• Copper indium gallium diselenide (CIGS) alloy
Third Generation
• Nanocrystal solar cells
• Photoelectrochemical (PEC) cells
Gräetzel cells
• Polymer solar cells
• Dye sensitized solar cell (DSSC)
Fourth Generation
•Hybrid - inorganic crystals within a polymer matrix
DEVELOPMENT OF SOLAR CELL
Specifications of Solar PV Systems
l Solar Lantern
l Uses 7 watt compact fluorescent lamp, 10watt PV module and a 7AH – 12 V sealedmaintenance free battery. Designed towork for about 3-4 hr a day:
Cost Rs. 3500/-
l Street light system
l Uses 40 watt fluorescent lamp, 74 Wp PVmodule and a 80 AM – 12 V battery:
Cost Rs. 25000/-
l Solar Home System
l Several modules, uses 18/37/74 Wp PVmodule and a 20/40/75 AH – 12 Vtubular plate battery and work for 3-5 hreach day. Cost Rs. 8,000 – 30,000/-
l Solar PV Water pump
l Small to large capacity ranging from 300– 3000 Wp PV array pumps are availableto draw water from a depth of 6-10 m.
l 1800 watt PV array pump with 2 hp DCmotor pump was able to deliver about1,40,000 litres of water per day from adepth of 6-10 m.
•It is expected to supply electricity at around Rs 8 per kWh.
•The 151-megawatt photovoltaic plant.
•World’s 2nd largest & Asia’s Largest solar project (Single
Plant).
•Set up at a cost of Rs. 1100 crore on 305 hectares of land.
India’s largest solar
photovoltaic plant has been
commissioned at Bhagwanpur
in Neemuch (Madhya
Pradesh). The plant with
installed capacity of 151-MW
has been developed by
Welspun Energy Ltd (WEL) &
completed in Feb. 2014
India’s largest solar photovoltaic plant (151 MW)
