SOLAR POWER TOWER TECHNOLOGY

Presented by:Harnish 10beer028Bhavin 10beer027

zeel 10beer032

CONTENTSIntroductionOverview on SPTTHistorySystem DescriptionBenefits of SPTTAdvantages & DisadvantagesApplicationsConclusions

Introduction Solar power towers generate electric power from sunlight by focusing Solar power towers generate electric power from sunlight by focusing

concentrated solar radiation on a tower-mounted heat exchanger concentrated solar radiation on a tower-mounted heat exchanger (receiver).(receiver).

It uses an array of flat, moveable mirrors (called heliostats) to focus It uses an array of flat, moveable mirrors (called heliostats) to focus the sun's rays upon a collector tower (the target).the sun's rays upon a collector tower (the target).

The high energy at this point of concentrated sunlight is transferred to a The high energy at this point of concentrated sunlight is transferred to a substance that can store the heat for later use. substance that can store the heat for later use.

The more recent heat transfer material that has been successfully The more recent heat transfer material that has been successfully demonstrated is liquid sodium.demonstrated is liquid sodium.

Sodium is a metal with a high heat capacity, allowing that energy to be Sodium is a metal with a high heat capacity, allowing that energy to be stored and drawn off throughout the evening.stored and drawn off throughout the evening.

Stored energy can be used to boil water for use in steam turbines.Stored energy can be used to boil water for use in steam turbines.

Overview The largest power towers ever built are the 10 MW (Solar One and Solar The largest power towers ever built are the 10 MW (Solar One and Solar

Two plants). Assuming success of the Solar Two project, the next plants Two plants). Assuming success of the Solar Two project, the next plants could be scaled-up to between 30 and 100 MW.could be scaled-up to between 30 and 100 MW.

As non-polluting energy sources become more favored, molten-salt power As non-polluting energy sources become more favored, molten-salt power towers will have a high value because the thermal energy storage allows towers will have a high value because the thermal energy storage allows the plant to be dispatch able.the plant to be dispatch able.

The value of power is worth more because a power tower plant can The value of power is worth more because a power tower plant can deliver energy during peak load times when it is more valuabledeliver energy during peak load times when it is more valuable

New peaking and intermediate power sources are needed today in many New peaking and intermediate power sources are needed today in many areas of the developing World. areas of the developing World.

One possible concern with the technology is the relatively high amount of One possible concern with the technology is the relatively high amount of land and water usage.land and water usage.

History Solar technology is not new process. Its history spans from the 7thCentury B.C. to Solar technology is not new process. Its history spans from the 7thCentury B.C. to

today. We started out concentrating the sun’s heat with glass and mirrors to light today. We started out concentrating the sun’s heat with glass and mirrors to light fires. Today, we have everything from solar-powered buildings to solar powered fires. Today, we have everything from solar-powered buildings to solar powered vehicles.vehicles.

Solar One, which operated from 1982 to 1988, was the world’s largest power Solar One, which operated from 1982 to 1988, was the world’s largest power tower plant. It proved that large-scale power production with power towers was tower plant. It proved that large-scale power production with power towers was feasible. feasible.

During the operation of Solar One, research began on the more advanced molten-During the operation of Solar One, research began on the more advanced molten-salt power tower design described. This development culminated in the Solar Two salt power tower design described. This development culminated in the Solar Two project.project.

Solar Two, which is currently going through its startup phase, will generate (in Solar Two, which is currently going through its startup phase, will generate (in addition to electric power) information on the design, performance, operation and addition to electric power) information on the design, performance, operation and maintenance of molten-salt power towers.maintenance of molten-salt power towers.

Solar Two is expected to begin routine daily power production in late 1997.Solar Two is expected to begin routine daily power production in late 1997.

System Description Solar power tower convert sunshine into clean electricity. The technology uses Solar power tower convert sunshine into clean electricity. The technology uses

many large, sun-tracking mirrors commonly referred as heliostats to focus sunlight many large, sun-tracking mirrors commonly referred as heliostats to focus sunlight on a receiver at the top of a tower.on a receiver at the top of a tower.

The enormous amount of energy, coming out of the sun rays, concentrated at one The enormous amount of energy, coming out of the sun rays, concentrated at one point (the tower in the middle), produces temperatures of approx. 550°C to point (the tower in the middle), produces temperatures of approx. 550°C to 1500°C.1500°C.

The gained thermal energy can be used for heating water or molten salt, which The gained thermal energy can be used for heating water or molten salt, which saves the energy for later use. Heated water converts to steam, which is used to saves the energy for later use. Heated water converts to steam, which is used to move the turbine-generator. This way thermal energy is converted into electricity.move the turbine-generator. This way thermal energy is converted into electricity.

Water is the oldest and simplest way for heat transfer. But the difference is that Water is the oldest and simplest way for heat transfer. But the difference is that the method in which molten salt is used, allows storing the heat when the sun is the method in which molten salt is used, allows storing the heat when the sun is behind clouds or even at night. behind clouds or even at night.

Continued…. As already mentioned there are two main fluids which are used for the heat As already mentioned there are two main fluids which are used for the heat

transfer, water and molten salt. transfer, water and molten salt.

If water is used as Heat transfer fluid then it is If water is used as Heat transfer fluid then it is First generation of solar power First generation of solar power tower plant. (i.e. Solar One)tower plant. (i.e. Solar One)

If Molten salt is used as Heat transfer fluid then it is If Molten salt is used as Heat transfer fluid then it is Next generation of solar Next generation of solar power tower plant. (i.e. Solar Two)power tower plant. (i.e. Solar Two)

HELIOSTATHELIOSTAT• Heliostat is termed Greek word Heliostat is termed Greek word Helios- sunHelios- sun stat - stationarystat - stationary• A Heliostat is a device that tracks the movement of the sun.A Heliostat is a device that tracks the movement of the sun.• The reflected sunlight from the heliostats can generate an enormous amount of The reflected sunlight from the heliostats can generate an enormous amount of

heat if all are oriented towards the same target. heat if all are oriented towards the same target. • These are also called as sun tracking mirrors.These are also called as sun tracking mirrors.

Solar one Solar One was the world’s largest power tower plant. In that plant, water Solar One was the world’s largest power tower plant. In that plant, water

was converted to steam in the receiver and used directly for conventional was converted to steam in the receiver and used directly for conventional Rankine-cycle steam turbine to generate power. Rankine-cycle steam turbine to generate power.

The Solar One thermal storage system works by storing heat in the form The Solar One thermal storage system works by storing heat in the form of steam generated using solar energy in a tank which is filled with rocks of steam generated using solar energy in a tank which is filled with rocks and sand and using oil as the heat-transfer fluid. and sand and using oil as the heat-transfer fluid.

The Solar One thermal storage system extended the power generation The Solar One thermal storage system extended the power generation capability of the plant into the night and provided heat for generating capability of the plant into the night and provided heat for generating low-grade steam for keeping parts of the plant warm during off-hours and low-grade steam for keeping parts of the plant warm during off-hours and for morning startup. for morning startup.

Disadvantage of solar one technologyDisadvantage of solar one technology Solar One thermal storage system was complex and thermodynamically Solar One thermal storage system was complex and thermodynamically

inefficient. inefficient. Solar One also showed the disadvantages of a water/steam system, such Solar One also showed the disadvantages of a water/steam system, such

as the intermittent operation of the turbine due to cloud transience and as the intermittent operation of the turbine due to cloud transience and lack of effective thermal storage. lack of effective thermal storage.

Solar Two

The conversion of Solar One to Solar Two required a new (molten-salt) heat transfer The conversion of Solar One to Solar Two required a new (molten-salt) heat transfer system and a new control system. This includes the receiver, thermal storage, piping, system and a new control system. This includes the receiver, thermal storage, piping, and a steam generator.and a steam generator.

The Solar Two power tower is composed of a series of panels (each made of 32 thin-The Solar Two power tower is composed of a series of panels (each made of 32 thin-walled), stainless steel tubes, through which the molten salt flows in a serpentine walled), stainless steel tubes, through which the molten salt flows in a serpentine path.path.

A black Pyromark paint which is robust, resistant to high temperatures and thermal A black Pyromark paint which is robust, resistant to high temperatures and thermal cycling and absorbs 95% of the incident sunlight is used to coat the external surfaces cycling and absorbs 95% of the incident sunlight is used to coat the external surfaces of the tubes.of the tubes.

The design including laser-welding, a tube clip design that facilitates tube expansion The design including laser-welding, a tube clip design that facilitates tube expansion and contraction, and non-contact flux measurement devices, allows the receiver to and contraction, and non-contact flux measurement devices, allows the receiver to rapidly change temperature without being damaged. rapidly change temperature without being damaged.

Advantages of Using solar two

A variety of fluids were tested to transport the sun's heat, including A variety of fluids were tested to transport the sun's heat, including water, air, oil, and sodium. In that, molten salt was selected as best. water, air, oil, and sodium. In that, molten salt was selected as best.

Molten salt is an efficient, low cost medium to store thermal energy.Molten salt is an efficient, low cost medium to store thermal energy.

Molten salt operating temperatures are compatible with today’s high-Molten salt operating temperatures are compatible with today’s high-pressure and high-temperature steam turbines.pressure and high-temperature steam turbines.

it is non-flammable and nontoxic. it is non-flammable and nontoxic.

Benefits of Solar Power Towers Solar power towers are fueled by sunshine and do not release Solar power towers are fueled by sunshine and do not release

greenhouse gases. greenhouse gases. Solar power towers are unique among solar electric Solar power towers are unique among solar electric

technologies in their ability to efficiently store solar energy technologies in their ability to efficiently store solar energy and dispatch electricity to the grid when needed, even at and dispatch electricity to the grid when needed, even at night or during cloudy weather. night or during cloudy weather.

Environmental Benefits of Solar Power TowersEnvironmental Benefits of Solar Power Towers

No hazardous gaseous or liquid emissions are released during No hazardous gaseous or liquid emissions are released during operation of the solar power tower plant.operation of the solar power tower plant.

Salt can be recycled if necessary.Salt can be recycled if necessary. If the power tower is hybridized with a conventional fossil If the power tower is hybridized with a conventional fossil

plant, emissions will be released from the non-solar portion plant, emissions will be released from the non-solar portion of the plant.of the plant.

Advantages of SPTT Solar energy comes directly from the sun it is not only renewable, but also Solar energy comes directly from the sun it is not only renewable, but also

accessible in any part of the world. accessible in any part of the world. Solar power is also one of the cleanest forms of energy, since it creates no Solar power is also one of the cleanest forms of energy, since it creates no

pollution, and produces no greenhouse gases or waste products.pollution, and produces no greenhouse gases or waste products.

Solar Power is safer alternative to WIND & HYDRO POWER.Solar Power is safer alternative to WIND & HYDRO POWER.

Not only solar energy is non-pollutant, in terms of gases, but it also causes zero Not only solar energy is non-pollutant, in terms of gases, but it also causes zero noise pollution – since there are no moving parts in any of the devices which are noise pollution – since there are no moving parts in any of the devices which are used to capture the sunlight.used to capture the sunlight.

Maintenance costs are low as well – only occasional cleaning and periodic battery Maintenance costs are low as well – only occasional cleaning and periodic battery replacements are needed.replacements are needed.

Most manufacturers of solar panels provide twenty-year warranties for their Most manufacturers of solar panels provide twenty-year warranties for their equipment, guaranteeing long-life operation.equipment, guaranteeing long-life operation.

DisadvantagesDisadvantages The most obvious drawback of solar energy is its sole dependence on the The most obvious drawback of solar energy is its sole dependence on the

sun. Once the weather becomes cloudy or night time strikes, energy sun. Once the weather becomes cloudy or night time strikes, energy collection comes to a halt. collection comes to a halt.

Solar panels can also be expensive, because of the materials that are used Solar panels can also be expensive, because of the materials that are used to create them. This includes portable devices that utilize solar energy. to create them. This includes portable devices that utilize solar energy.

Fortunately, there are some people who sell damaged solar cells, which Fortunately, there are some people who sell damaged solar cells, which are much cheaper. These damaged solar cells are be used to build solar are much cheaper. These damaged solar cells are be used to build solar panels.panels.

It is also true that direct sunlight is needed in order to make the most of It is also true that direct sunlight is needed in order to make the most of the sun’s energy– and to generate the highest amounts of power. This the sun’s energy– and to generate the highest amounts of power. This significantly restricts the placement of solar panelssignificantly restricts the placement of solar panels

Huge amount of water and land is required.Huge amount of water and land is required.

Applications Of SPTT Solar Powered LED lighting system provides bright light charged by Solar Powered LED lighting system provides bright light charged by

sunlight. Suitable for wherever the grid electricity is unreliable or sunlight. Suitable for wherever the grid electricity is unreliable or unavailable.unavailable.

In order to supply Electricity for street lights, solar power tower In order to supply Electricity for street lights, solar power tower

technologies are used.technologies are used. Solar Power can be used as Alternative for Wind & Hydro power.Solar Power can be used as Alternative for Wind & Hydro power. These plants are best suited for utility-scale applications in the 30 to 400 These plants are best suited for utility-scale applications in the 30 to 400

MW range.MW range.

Provides rough enough Electricity for night use & during Cloudy weather.Provides rough enough Electricity for night use & during Cloudy weather.

Solar tower technology produces air above 1000°C or synthesis gas for gas Solar tower technology produces air above 1000°C or synthesis gas for gas turbine operation.turbine operation.

SOLAR TWO POWER TOWER TECHNOLOGY

Conclusions1. It is very efficiency system can be increased by hybridizing it

with the other conventional plants.

2. Very economy excluding initial cost.

3. Can be implemented with alternative like WIND and HYDRO power generation.

4. Molten salt has the best Heat capacity.

5. Non pollutant power technology.

6. It will be the power source for developing countries.

REFERENCES

1. google1. google 2.www.aurthorstream.com2.www.aurthorstream.com 3.www.wikepedia.org3.www.wikepedia.org 4.www.sesi.com4.www.sesi.com

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