CSP for electricity generation: Dish-Stirling system

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CSP for electricity generation Dish-Stirling
system
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CSP for electricity generation Dish-Stirling
system
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CSP for electricity generation Dish-Stirling
system

• - A parabolic dish-shaped (e.g., satellite dish)
  reflector rotates to track the sun.
• The reflector concentrates sun radiation onto a
  receiver.
• At the receiver, energy is transferred to
  hydrogen in a closed loop.
• Heated hydrogen (up to 650oC) expands against a
  piston or turbine producing mechanical power.

http//www.volker-quaschning.de/articles/fundament
als2/index.php
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CSP for electricity generation Dish-Stirling
system
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CSP for electricity generation Dish-Stirling
system

• Heated hydrogen (up to 650oC) expands against a
  piston or turbine producing mechanical power.
• This power is used to run a generator to produce
  electricity in kilowatts range.
• - The power conversion unit is air cooled, so
  water cooling is not needed.
• Up to 20 efficiency is possible, but costly

http//www.volker-quaschning.de/articles/fundament
als2/index.php
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CSP for electricity generation Dish-Stirling
system
300 MW commercial solar thermal power plant in
California
https//www.mtholyoke.edu/wang30y/csp/ParabolicDi
sh.html
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Major solar energy conversion technologies
Solar Photovoltaics (Solar PVs)
are arrays of cells containing a semiconductor
material that converts solar radiation into
direct current (DC) electricity.
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Solar PVs
PV cell turns sunlight directly into DC
electricity. Total of installed PV was more
than 16 GW in 2008.
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Solar PVs
When photons (sunlight) hits the semiconductor,
an electron springs up and is attracted to the
n-type semiconductor. This causes more negative
electrons in the n-type semiconductor and more
positive electrons in the p-type. Thus a flow of
electricity is generated in a process known as
the photovoltaic effect.
Commercially available solar cells achieve solar
energy to electricity conversion efficiencies of
approximately 15.
http//global.kyocera.com/solarexpo/solar_power/me
chanism.html
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Solar PVs
How much electricity can we get from solar roof?
Roof area (assumed) 10 m2 (all covered with PV
cells) Solar radiation on earth 2 6
kWh/m2/day (from http//www.nrel.gov/docs/fy03ost
i/34645.pdf) Conversion efficiency 20 (max
in the market) Electricity obtainable 0.2 x
(2 6) x 10 kWh/day 4 12 kWh/day
166 500 W 3 to 8 bulbs of 60 W strength
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Solar PVs
Photovoltaic Power for Rural Homes In Sri Lanka
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Solar PVs
7W CFL, 12V Electronics, 10Wp Panel 7Ah MF
Battery Backup 3 to 4 hoursSolar Panel
Warrantee 10 yearsLantern Warrantee 1 year
Solar lantern About Rs 2500/
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Solar PVs
Photovoltaic 'tree'
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Solar PVs

• The Pocking Solar Park is a 10 MWp PV solar power
  plant.
• - started in August 2005
• completed in March 2006

US87 million
sheep are now grazing under and around the 57,912
photovoltaic modules
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Solar PVs
World's largest PV Power Stations - Huanghe
Hydropower Golmud Solar Park (China, 200 MW) -
Perovo Solar Park (Ukraine, 100 MW), - Sarnia PV
Power Plant (Canada, 97 MW) - Montalto di Castro
PV Power Station (Italy, 84.2 MW) - Senftenberg
Solarpark (Germany, 82 MW) - Finsterwalde Solar
Park (Germany, 80.7 MW) - Okhotnykovo Solar Park
(Ukraine, 80 MW)
(completed in 2010 and 2011)
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Solar PVs

• Large PV Power Stations
• in planning / under construction
• - Ordos Solar Project (China, 2000 MW)
• Barmer, Bikaner, Jaisalmer and Jodhpur Solar
  Projects (India, 1000 MW each)
• Calico Solar Energy Project (USA, 563 MW)
• Topaz Solar Farm (USA, 550 MW)
• and more.

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Solar PVs
Inorganic Solar Cells
2nd Generation Thin-film
Bulk
Silicon
3rd Generation Materials
Germanium
Silicon
CIS
Amorphous Silicon
CIGS
Mono-crystalline
CdTe
Poly-crystalline
Nonocrystalline Silicon
GaAs
Ribbon
Light absorbing dyes
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Solar PVs
Inorganic Solar Cells
2nd Generation Thin-film
Bulk
Silicon
3rd Generation Materials
CdTe (cadmium telluride) is easier to deposit and
more suitable for large-scale production.
Chinas 2000 MW PV plant will use this
technology. Cd is however toxic.
Germanium
Silicon
CIS
Amorphous Silicon
CIGS
Mono-crystalline
CdTe
Poly-crystalline
Nonocrystalline Silicon
GaAs
Ribbon
Light absorbing dyes
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Solar PVs
Inorganic Solar Cells
2nd Generation Thin-film
Bulk
Silicon
3rd Generation Materials
GaAs (gallium arsenide) is highly toxic and
carcinogenic. When ground into very fine
particles (wafer-polishing processes), the high
surface area enables more reaction with water
releasing some arsine and/or dissolved arsenic.
Germanium
Silicon
CIS
Amorphous Silicon
CIGS
Mono-crystalline
CdTe
Poly-crystalline
Nonocrystalline Silicon
GaAs
Ribbon
Light absorbing dyes
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Solar PVs
Inorganic Solar Cells
2nd Generation Thin-film
Bulk
Processing silica (SiO2) to produce silicon is a
very high energy process, and it takes over two
years for a conventional solar cell to generate
as much energy as was used to make the silicon it
contains. Silicon is produced by reacting
carbon (charcoal) and silica at a temperature
around 1700 deg C. And, 1.5 tonnes of CO2 is
emitted for each tonne of silicon (about 98
pure) produced.
Silicon
3rd Generation Materials
Germanium
Silicon
CIS
Amorphous Silicon
CIGS
Mono-crystalline
CdTe
Poly-crystalline
Nonocrystalline Silicon
GaAs
Ribbon
Light absorbing dyes
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Solar PVs
Inorganic Solar Cells
2nd Generation Thin-film
Germanium is an un-substitutable industrial
mineral. 75 of germanium is used in optical
fibre systems, infrared optics, solar electrical
applications, and other speciality glass
uses. Germanium gives these glasses their
desired optical properties. Germanium use will
likely increase with solar-electric power becomes
widely available and as optic cables continue to
replace traditional copper wire.
Bulk
Silicon
3rd Generation Materials
Germanium
Silicon
CIS
Amorphous Silicon
CIGS
Mono-crystalline
CdTe
Poly-crystalline
Nonocrystalline Silicon
GaAs
Ribbon
Light absorbing dyes
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Solar PVs
Calculation of United States Sustainable
Limiting Rate of Germanium Consumption

• Step 1 Virgin material supply limit
• The reserve base for germanium in 1999
  500 Mg
• So the virgin material supply limit over the next
  50 years
• 500 Mg / 50 years
• 
  10 Mg/yr

Source Graedel, T.E. and Klee, R.J., 2002.
Getting serious about sustainability, Env. Sci.
Tech. 36(4) 523-9
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Solar PVs
Calculation of United States Sustainable
Limiting Rate of Germanium Consumption

• Step 2 Allocation of virgin material
• Average U.S. population over the next 50 years
• 340 million
• Equal allocation of germanium among the average
  U.S. population gives
• (10 Mg/yr) / 340 million
• 29 mg / (person.yr)

Source Graedel, T.E. and Klee, R.J., 2002.
Getting serious about sustainability, Env. Sci.
Tech. 36(4) 523-9
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Solar PVs
Calculation of United States Sustainable
Limiting Rate of Germanium Consumption

• Step 3 Regional re-captureable resource base
• Worldwide germanium production from recycled
  material
• 25 of the total germanium consumed
• Equal allocation of virgin germanium among the
  average U.S. population therefore becomes 1.2529
  mg / (person.yr)
• 36 mg / (person.yr)
• The sustainable limiting rate of germanium
  consumption in U.S. is thus 36 mg / (person.yr)

Source Graedel, T.E. and Klee, R.J., 2002.
Getting serious about sustainability, Env. Sci.
Tech. 36(4) 523-9
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Solar PVs
Calculation of United States Sustainable
Limiting Rate of Germanium Consumption

• Step 4 Current consumption rate vs. sustainable
  limiting rate
• Germanium consumption in U.S. in 1999 28 Mg
• Population in U.S. in 1999 275 million
• So, germanium consumption rate in U.S. in 1999
• 28 Mg / 275 million 102 mg / (person.yr)
• which is about 2.8 times the sustainable limiting
  rate of germanium consumption in U.S.

Source Graedel, T.E. and Klee, R.J., 2002.
Getting serious about sustainability, Env. Sci.
Tech. 36(4) 523-9
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Solar Energy

• - Solar power systems generate no air pollution
  during operation.
• Environmental, health, and safety issues involve
  how they are manufactured, installed, and
  ultimately disposed of.
• Energy is required to manufacture and install
  solar components, and any fossil fuels used for
  this purpose will generate emissions.
• Thus, an important question is how much fossil
  energy input is required for solar systems.

http//www.ucsusa.org/clean_energy/technology_and_
impacts/impacts/environmental-impacts-of.html
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Solar Energy

• Materials used in some solar systems can create
  health and safety hazards for workers and anyone
  else coming into contact with them.
• Manufacturing of PV cells often requires
  hazardous materials such as arsenic and cadmium.
• Even relatively inert silicon, a major material
  used in solar cells, can be hazardous to workers
  if it is breathed in as dust.
• There is an additional-probably very
  small-danger that hazardous fumes released from
  PV modules attached to burning homes or buildings
  could injure fire fighters.

http//www.ucsusa.org/clean_energy/technology_and_
impacts/impacts/environmental-impacts-of.html
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Solar Energy

• Large amount of land is required for
  utility-scale solar power plants (approximately
  one square kilometer for every 20-60 MW
  generated).
• Disruption of what might have been pristine
  property
• Intensive construction activities and having
  large parabolic solar panels or mirrors taking up
  acres of land could displace migration routes and
  habitat of wildlife, flora and fauna.
• New solar installation sites are graded and
  sprayed with weed control chemicals. 
• Humans will be present on a more regular basis
  driving to the site in vehicles and disposing of
  trash, etc.

http//www.ucsusa.org/clean_energy/technology_and_
impacts/impacts/environmental-impacts-of.html
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Solar Energy

• Solar-thermal plants (like most conventional
  power plants) also require cooling water, which
  may be costly or scarce in desert areas.
• Large central power plants are not the only
  option for generating energy from sunlight.
• Because sunlight is dispersed, small-scale,
  dispersed applications are a better match to the
  resource.
• They can take advantage of unused space on the
  roofs of homes and buildings and in urban and
  industrial lots.
• And, in solar building designs, the structure
  itself acts as the collector, so there is no need
  for any additional space at all.

http//www.ucsusa.org/clean_energy/technology_and_
impacts/impacts/environmental-impacts-of.html
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Solar Energy

• CIS Tower, Manchester, England is 118 m
  skyscraper with a weatherproof cladding
  (replacing the mosaic tiles) around the tower
  made up of PV cells (alive dummy cells).
• It generates 21 kW electricity (enough to power
  61 average 3-bed houses) and feeds part of it to
  the national grid.

5.5 million
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Solar Energy
Photovoltaic Power for Rural Homes In Sri Lanka
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Solar Energy
Technological status niche markets
Average growth 10.6 per year
Total share of global energy mix 0.06 of electricity in 2008 0.54 of electricity in 2035 (potential)
Source International Energy Outlook 2011
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Total solar electricity generation projection
Average growth is 10.6 per year
Source International Energy Outlook 2011
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World electricity generation projection
Source International Energy Outlook 2011
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Comparison of Technologies
Technology Available energy (PWh/yr) Technical potential energy (PWh/yr) Current installed power (GW) Current electricity generation (TWh/yr)
Hydroelectric 16.5 lt 16.5 778 2840
Solar PV 14900 lt3000 8.7 11.4
CSP 9250 11800 1.05 7.8 0.354 0.4
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Comparison of Technologies
Y. Bravo et al. / Solar Energy 86 (2012) 28112825