Transcript www.physics.utah.edu

Concentrated Solar Power
Energy & Sustainability Presentation
PHYS3150- Petra Huentemeyer
By: Matthew Baird
Alternatives to Photovoltaics?
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Collecting Solar
Power is favorable
Research still
required for PV to be
efficient
One solar technology
has already been
around for hundreds
of years
Ways we've used solar power....
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Solar Kitchen in
Auroville, India
Fixed reflector
One-axis receiver
tracking
Flexible reflecting
coating to change
curvature for seasonal
variations
Generates enough
steam to cook 2,000
daily meals
Solar Furnace in Odeillo, France
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Located in the French
Pyrenees, this
collector can achieve
temperatures of 3,800
degrees Celsius
The heat is used to
for large commercial
buildings
Concentrated Solar Power (CSP)
or, Solar Thermal
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Magnifying Glass trick
Archimedes, in 216 B.C.,
allegedly helped protect
Syracuse from the
Romans by focusing
light.
Heating systems for
swimming pools,
commerce, and homes
Evaporation ponds are
the most used of all solar
technologies.
Where CSP stands today
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Programs ongoing in the
US DOE, grants for
research and
improvements of the
technology
There are four typical
designs of CSP now being
utilized
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Tower of Power-->
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Parabolic Trough
Systems
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Fresnel reflectors
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Dish/Stirling type
State of CSP cont.
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Link for current DOE funded R&D projects
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Link for projects through NREL(National
Renewable Energy Laboratory)
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http://www1.eere.energy.gov/solar/csp_industr
y_projects.html#thermal
http://www.nrel.gov/csp/projects.html
DOE/NREL has an initiative to install 1000MW
of new CSP systems in the southwestern US by
2010
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With this level of deployment, analyst predict
consumer costs to be $0.07/kWHr which
Solar Resource Map of Utah
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Filtered by solar
resource and land
availability
Represent locations
that are economically
viable to develop
large scale CSP
systems
Full SW US map on
next slide...
Parabolic Trough Systems
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Utilize parabolic mirrors to concentrate light
onto a receiver that runs parallel to the mirror.
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All mirrors manufactured by Flabeg
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Second surface silvered glass
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Low iron glass, 4mm thick, with very high
transmittance
Solar weighted reflectivity ~93.5%
Each mirror is ~2m^2
The 80MW SEGS powerplant has 888 collector
assemblies, with a total close to 200,000
individual mirrors
Parabolic Trough Systems
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Synthetic oil is used for heat transfer usually
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Oil is heated to 400 degrees Celsius
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Using oil, instead of water to directly make steam,
keeps pressures at a manageable level
throughout the collector system
Some stats on the SEGS I-IX plants
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354MW capacity, with a capacity factor of 21%,
total average gross output is 75 Mwe
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Natural Gas can be burned during night to
continue utilizing turbines
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Claimed 232,500 homes are powered, with 3,800
tonnes of CO2 displaced each year
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Total area coverage of 6.5 km^2
Parabolic Trough Systems
Fresnel Reflectors
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Similar to Trough
Design
Easy to cover ground
area and track the
sun effectively, single
axis
An entire row of
mirrors reflect to a
single overhead
receiver
Fresnel Reflectors
Tower Of Power
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Many large, flat
mirrors reflect to a
receiver on top of a
tower
Water/steam or oil for
heat transfer to drive
turbine
From 1982-88 Solar
One in Barstow,CA
produced 38 million
kWh of electricity
Tower Of Power
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Solar II (retrofitted
solar I) now has the
capacity of using
molten salt as heat
transfer fluid and for
thermal storage
Developments are
under way for a
fresnel/TOP
combination
Dish/Stirling Designs
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Large(5-7m dia) individual
parabolic dish mirrors
reflect onto a thermal
receiver and stirling engine
which powers a generator
Advantage for distributed
power
Typically, same fluid is
used for heat transfer and
in engine
3-25 kW each unit typical
electricity generation
Net 30% efficiency
achieved
Future Improvements
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Advanced optical materials are key
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Reflective flexible coatings with ultra high
reflectance and which are durable and easy to
clean
Materials which have high heat capacities and
good thermal conductance
Continued optimization of design to drive down
capitol costs and increase efficiency
Clever heat transfer fluids which also double for
thermal storage so plant can generate electricity
at night
Benefits of using CSP
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Extremely limited environmental impacts, essentially
no CO2/NO2 emissions
Evolutionary instead of revolutionary technology,
resembles and uses much of the same equipment as
current fossil fuel plants, easy to incorporate into the
existing electricity infrastructure
Already proven to be dependable and efficient(SEGS)
Though initial investments are larger than other forms,
the fuel used is unlimited, we don't have to mine or
discover more which leads to heavy environmental
impacts
Fast approaching costs of fossil fuels
Sources
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U.S. Dept. of Energy
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National Renewable Energy Laboratory
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http://www1.eere.energy.gov/solar/csp.html
http://www.nrel.gov/csp/
International Energy Agency
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http://www.iea.org/
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http://en.wikipedia.org/wiki/Solar_power
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http://www.solarpaces.org/
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http://www.csptoday.com/us/