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HELIO TRACKER The amount of energy produced by most photovoltaic (solar) panels is limited, due to their immobility. However, when photovoltaic panels track the movement of the Sun, their efficiency increases significantly. This can be done with computers and sophisticated electronics, but for rural or wilderness settings, a "low-tech" sun tracker would be beneficial. A solution exists in nature: the sunflower.

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Page 1: helio tracker

HELIO TRACKERThe amount of energy produced by most photovoltaic (solar) panels is limited, due to their immobility. However, when photovoltaic panels track the movement of the Sun, their efficiency increases significantly. This can be done with computers and sophisticated electronics, but for rural or wilderness settings, a "low-tech" sun tracker would be beneficial. A solution exists in nature: the sunflower.

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HISTORYPHOTOVOLTAIC EFFECT :The photovoltaic effect is the creation of a voltage in a material upon exposure to light. The photovoltaic effect is different in that the generated electrons are transferred between different bands (i.e. from the valence to conduction bands) within the material, resulting in the buildup of a voltage between two electrodes.

SOLAR PANNEL :A solar panel (photovoltaic module or photovoltaic panel) is a packaged interconnected assembly of solar cells,also known as photovoltaic cells. The solar panel is used as a component in a larger photovoltaic system to offer electricity for commercial and residential applications.

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CONCENTRATED SOLAR SYSTEM

 .Concentrated solar power (CSP) systems use lenses or mirrors to focus a large area of sunlight onto a small area.

.Concentrated sunlight has been used to perform useful tasks from the time of ancient China. A legend has it that Archimedes used a "burning glass" to concentrate sunlight on the invading Roman fleet and repel them from Syracuse. In 1973 a Greek scientist, Dr. Ioannis Sakkas, curious about whether Archimedes could really have destroyed the Roman fleet in 212 BC lined up nearly 60 Greek sailors, each holding an oblong mirror tipped to catch the Sun's rays and direct them at a tar-covered plywood silhouette 160 feet away. The ship caught fire after a few minutes; however, historians continue to doubt the Archimedes story.

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DIVISION

Concentrated solar power systems are divided into:

.CONCENTRIC SOLAR THERMAL (CST)

.CONCENTRIC PHOTOVOLTAICS (CPV)

.CONCENTRIC PHOTOVOLTAICS AND THERMAL (CPVT)

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CONCENTRATED SOLAR THERMAL (CST):

. Concentrated solar thermal (CST) is used to produce renewable heat or cool or electricity (called solar thermoelectricity, usually generated through steam). CST systems use lenses or mirrors and tracking systems to focus a large area of sunlight onto a small area. The concentrated light is then used as heat or as a heat source for a conventional power plant (solar thermoelectricity).

The PS10 solar power tower near Seville concentrates sunlight from a field of heliostats on a central tower

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CONCENTRATED PHOTOVOLTAICS(CPV)

.Concentrated photovoltaics (CPV) systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production. Solar concentrators of all varieties may be used, and these are often mounted on a solar tracker in order to keep the focal point upon the cell as the Sun moves across the sky.

The 5 MW Sierra SunTower facility in Lancaster, California employs a field of heliostats concentrating sunlight onto a central tower.

A parabolic trough is the most widely deployed and proven type of solar thermal power plant.

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CONCENTRATED PHOTOVOLTAICS AND THERMAL(CPVT)Concentrating Photovoltaics and Thermal (CPVT) technology produces both electricity and thermal heat in the same module. Thermal heat that can be employed for hot tap water, heating and heat-powered air conditioning (solar cooling), desalination or solar process heat.

Nevada Solar One's fresnel reflectors are not as efficient as parabolic mirrors but are much cheaper.

The Holaniku at Keahole Point 2 MW concentrating parabolic trough solar power installation in Kona, Hawaii.

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EFFICIENCY

For thermodynamic solar systems, the maximum solar-to-work (ex: electricity) efficiency η can be deduced by considering both thermal radiation properties and the Carnot's theorem

THE VALUE OF EFFICIENCY IS GIVEN BY:

One sees that efficiency does not simply increase monotonically with the receiver temperature. Indeed, the higher the temperature, the higher the Carnot's efficiency, but also the lower the receiver efficiency.

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There is a temperature Topt for which the efficiency is maximum, i.e. when the efficiency derivative relative to the receiver temperature is null:

Consequently, this lead us to the following equation:

Solving numerically this equation allows to obtain the optimum process temperature according to the solar concentration ratio C (red curve on the figure below)

C 500 1000 5000 10000

45000 (max.

for Earth)

Tmax 1720 2050 3060 3640 5300

Topt 970 1100 1500 1720 2310

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TYPES OF TRACKERS :

1.FIXED AXIS TRACKER :

2. SINGLE AXIS TRACKER :

3.DOUBLE AXES TRACKER :

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1.FIXED AXIS TRACKER :The bases of these systems are designed and certified to the highest European standards. Resistant to construction from galvanized iron and structural aluminium that isn’t compacted but screwed, thus avoiding the use of concrete, offering great resistance to strong wind pressures

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Solar tracking systems are devices supporting a series of PV modules and following continuously the suns orbit resulting in a continuous torsion directly to the sun by maximizing efficiency in the production of electric energy in comparison with fixed PV bases.Eve lights solar tracking systems of single axis achieve significant maximize of the efficiency of a PV plant by 25-30%, because throughout the day the modules are turned directly to the sun.The single axis trackers follow the daily (azimuthally) motion of the sun, having constant inclination on the seasonal altitude of sun. This will significantly improve the efficiency in regard to fixed installation of photovoltaic cells.Therefore we achieve greater production of electricity and faster depreciation of the investment cost for the construction of the installation.

2. SINGLE AXIS TRACKER :

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3.DOUBLE AXES TRACKER :The incidence angle of solar radiation in solar cells is very important parameter to maximize performance. The maximum yield is obtained for vertical incidence. Obviously this is not possible for PV panels that are placed on a fixed basis. Thus, is needed a mobile base which monitors the movement of the sun throughout the day and for all seasons.The double axis trackers alter not only the azimuthally but also the elevation angle accurately monitoring the movement of the sun and achieving maximum efficiency.

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THEORY :

Renewable energy solutions are becoming increasingly popular. Photovoltaic (solar)system is one of the example. Maximizing power output from a solar system is desirableto increase efficiency. In order to maximize power output from the solar panels, oneneeds to keep the panels aligned with the sun. As such, a means of tracking the sun isrequired. This is a far more cost effective solution than purchasing additional solarpanels. It has been estimated that the yield from solar panels can be increased by 30 to60 percent by utilizing a tracking system instead of a stationary array.

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THANK YOU