Solar Thermal Energy
Parabolic Trough
The largest ‘solar thermal-electric’ installation of its kind in the world,
the Luz project in California’s Mojave Desert, has a peak output of some
350 megawatts and occupies several square kilometers of land
Solar Power Tower
In 1995 Solar One was converted into Solar Two, by adding a second ring
of 108 larger 95 m² (1,000 ft²) heliostats around the existing Solar One,
totaling 1926 heliostats with a total area of 82,750 m² (891,000 ft²)
Solar Dish
Stirling Energy Systems‘ solar dish technology is the world’s most efficient
device for the conversion of solar energy to grid-delivered electricity,
nearly twice as efficient as any alternative solar technology.
Plant Locations
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Direct normal solar radiation
Land Ownership
Road Access
Local transmission infrastructure
capabilities and loadings
• State-level policies and regulations
U.S. Solar Resource Maps
U.S. Solar Resource Maps
Economic and Environmental Benefits
• Creation of jobs for both construction and
operation
• Increase in state and local tax revenues
• Increase in gross state output
Market Development
• The Southwest CSP has set a goal of
achieving 1,000 MW of CSP systems in
the southwestern US by 2010.
• US DOE’s goal is to develop 30,000 MW
of new clean and diversified generation by
2015.
• SolarPaces plans to deploy 5,000 MW of
CSP by 2015.
Residential Applications
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Solar Heating
Solar Cooling
Solar Hot Water
Solar Lighting
Types of Solar Water Heating Systems
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Flat-plate collector
– Glazed flat-plate collectors are insulated, weatherproofed boxes that
contain a dark absorber plate under one or more glass or plastic covers.
Unglazed flat-plate collectors; typically used for solar pool heating, have a
dark absorber plate, made of metal or plastic, without a cover or enclosure.
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Integral collector-storage systems
– Also known as ICS or batch systems, they feature one or more black tanks
or tubes in an insulated, glazed box. Cold water first passes through the
solar collector, which preheats the water. The water then continues on to
the conventional backup water heater, providing a reliable source of hot
water. In cold winter climates these systems must be drained to avoid
freezing.
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Evacuated-tube solar collectors
– They feature parallel rows of transparent glass tubes. Each tube contains a
glass outer tube and metal absorber tube attached to a fin. The fin's
coating absorbs solar energy but inhibits radiative heat loss. These
collectors are used more frequently for U.S. commercial applications.
Active solar water heating systems
• Direct circulation systems
– Pumps circulate household water through the
collectors and into the home. They work well
in climates where it rarely freezes.
• Indirect circulation systems
– Pumps circulate a non-freezing, heat-transfer
fluid through the collectors and a heat
exchanger. This heats the water that then
flows into the home. They are popular in
climates prone to freezing temperatures.
Passive solar water heating systems
• Integral collector-storage passive systems
– These work best in areas where temperatures rarely
fall below freezing. They also work well in households
with significant daytime and evening hot-water needs.
• Thermosyphon systems
– Water flows through the system when warm water
rises as cooler water sinks. The collector must be
installed below the storage tank so that warm water
will rise into the tank. These systems are reliable, but
contractors must pay careful attention to the roof
design because of the heavy storage tank. They are
usually more expensive than integral collector-storage
passive systems.
Comparison
• Passive solar water heating systems are
typically less expensive than active
systems, but they're usually not as
efficient. However, passive systems can
be more reliable and may last longer.
Passive solar home
• Passive solar homes range from those
heated almost entirely by the sun to those
with south-facing windows that provide
some fraction of the heating load. The
difference between a passive solar home
and a conventional home is design. The
key is designing a passive solar home to
best take advantage of your local climate.
For more information, see how a passive
solar home design works.
Solar Water Heat
Solar Collector
• Solar Thermal is a clean, highly efficient
means of using renewable energy from the
sun to provide hot water for domestic,
commercial and industrial process . Put in
simple terms, if you place a container full
of liquid in the garden on a sunny day, in a
short time the contents of the container
become warm. Solar Collectors work in
much the same way, but are very more
efficient.
• A sealed circuit of fluid containing a
special mix of glycol and water is pumped
around the system through the Solar
panels where it is heated and passed
through a special solar coil within the hot
water tank. The heat is then transferred to
the main body of water within the tank,
once up to temperature, this water is ready
for use in the house, office or factory.
Passive Solar
• Passive Solar is accommodated in the design
of some homes where living rooms are south
facing with large windows and floors and
sometimes walls have a large thermal mass.
• While it is necessary to use the solar to heat in
winter overheating in summer has to be avoided,
this is normally done by having a roof overhang
which blocks the high summer sun but not the
low winter sun.
• While it can provide some free heat it doesn’t
supply hot water and there are design
constraints.
Solar Collector
Processes at a flat-plate collector
Principle of an evacuated tube collector with heat pipe; view from top
A thermosyphon system
A double-cycle system with forced circulation with a conventional boiler
for back-up heating
Collector efficiencies at different irradiances and temperature differences
A solar district heating system
Solar Collector Markets
• China is by far the world’s largest manufacturer and user
of solar water heating.
• By the end of 2002, the total installed area of solar
domestic hot water systems there was about 40 million
m²; annual production and sales volume reached about 8
million m² in 2002.
• There are now more than 1000 manufacturers producing
and selling solar thermal systems, and a total turnover of
more than €1 billion has been achieved.
• Evacuated-tube collectors dominate the Chinese
domestic and export markets.
• Elsewhere, about 1 million m² of collector surface was
installed in the US by 2001; almost all of this was made
up of unglazed absorbers used for swimming pool
heating.
Solar Collector Markets
• In Europe, there was about 1.1 million m² of collector
area installed by 2002, and the flat-plate collector
dominates installations.
• About half of these installations have been realized in
Germany.
• The solar collector market mainly depends on political
conditions in a particular country, and in Germany, for
instance, the collector market dropped by 40% in 2002
due to uncertain political conditions, though it recovered
again in 2003.
• However, the EU has very ambitious targets for collector
installations, with a target of 100 million m² by 2010.
• Solar thermal systems will then play an important role in
the struggle against global warming.
Solar PV Systems - Solar Lighting
& Electricity
Hybrid solar technology
• Developed at Oak Ridge National Laboratory,
the hybrid solar technology uses a rooftopmounted 48-inch diameter collector and
secondary mirror that track the sun throughout
the day using GPS.
• The collector system focuses the sunlight into
127 optical fibers connected to special light
fixtures equipped with diffusion rods similar to
fluorescent light bulbs.
• The rods spread light in all directions.
Hybrid solar technology
• Hybrid solar lighting systems are being tested in
various demonstration projects around the
country including a Wal-Mart in McKinney,
Texas, a Staples store in Long Island, N.Y., a
Braden’s Furniture showroom in Knoxville,
Tenn., the Naval Exchange in Hawaii, some
office space at San Diego State University, the
Aveda corporate headquarters in Minneapolis
and Oak Ridge National Lab’s Multi-Purpose
Research Facility.
Radiation of energy to and from the earth