FIELD OF INVENTION:
This invention relates to the novel system for harnessing solar energy into electricity through photo-voltaic panels.
BACKGROUND:
Electric power generated from solar energy through crystalline-silicon and other semiconductor grade photovoltaic materials is a well-known alternative to conventional sources of energy. Being totally green, it also addresses today's major global concern of environment preservation and thrust towards a green planet.
Greatest deterrent to the wide-scale adoption of PV technology is the high unit cost of PV power when compared to power from conventional thermal & hydro-electric stations. And this remains so despite intense world-wide R&D over the last four decades. Very high capital costs, 4 times higher, and extremely low Plant Load Factors over the year due to basic characteristics of our solar cycle and inherent properties of current PV materials, contribute to poor economic viability. Besides high cost of PV materials and processes, low density per m2 of solar energy and need for protection against rain, hailstones, bird-pecking, stone-hits etc because of exposure to the open environment adds to cost of PV panels.
Common PV panels are oblong 1.5 to 2 m2 in area and power output of the best of Poly-crystalline silicon-wafer panels under simulated-lab conditions of peak sunlight, termed "peak" in PV parlance, ranges between 150-200 watts. Cost of large land areas required for setting-up PV power-plants because of low density of solar energy, plus land to be necessarily left vacant to avoid inter se shadowing of panels as sun transits the horizon and, on laying special power-lines to connect distant 24X7 power-grids add to capital costs.
Even for a sun-blessed country like India with its high daylight hours of 14 in summer and 9 in winter and, high intensity of solar energy of 600-900 watts/m2 in summer and 250 in winter, natural characteristics of the solar cycle and, moisture, dust and pollutants in the atmosphere which reflect solar energy back into space, result in poor Plant Load Factor (PLF) of PV installations in plains. Overall PLF over the year is barely 12-16% of peak capacity of current PV installations with modules on fixed structures. PLF in photovoltaic technology is the ratio of annual-average of daily KWh (units) of power generated compared to what it would be if it operating at Peak Power Capacity called KWp of the PV installation.

Mechanisms for auto-tracking of the sun as it moves across the horizon to improve PLF have been developed but they are complex and expensive. Complexity results in poor maintainability across the extended life of 25-30 years demanded from PV installations for economic viability. This has restricted their application to experimental installations.
All these factors have deterred planners from large-scale harnessing of solar energy for power, even though it is free, plentiful and infinite in a tropical country like India and many promotional incentives by government. Recent global emphasis on Green Energy for saving the environment has added new urgency.
Electric power from solar energy through crystalline-silicon and other semi-conductor grade photo-voltaic materials is a well-known alternative to conventional sources of energy. However, despite intense world-wide research and development over the last four decades in solar power generation, the per megawatt capital cost of approximately Rs. 25,00,00,000 (Rupees twenty five crores) when compared to the conventional thermal plants with a capital cost of about Rs. 5 crores per MW is a great deterrent to the wide-scale adoption of PV technology. The typical solar panel also known as photovoltaic (PV) panel commonly available achieves between 10% to 16% conversion only. Very high capital costs, approximately, 4 times higher, and extremely low Plant Load Factors over the year due to basic characteristics of our solar cycle and inherent properties of current photo-voltaic materials, contribute to poor viability.
Common PV panels are oblong 1.5 to 2 m2 in area and power output of the best of Poly-crystalline silicon-wafer panels under simulated-lab conditions of peak sunlight, termed "peak" in photo-voltaic parlance, ranges between 150-200 watts. Solar grade photovoltaic wafer-modules are 300 micron thick, very delicate and expensive. Power output per wafer of the common 6" pseudo-square wafer at 510 mV is only 2.4 watts. For meaningfully usable power, wafers are always connected and mounted in arrays. Mounting in the open adds its own demands vis-a-vis protection against rain, hailstones, bird-pecking, stone-throwing, proofing against scratches while dust-wiping etc. This results in mounting the photo-voltaic wafer modules on a rigid-base sealed encasement with top-face protected by tempered glass, weighing around 20 kg for a typical 150 watt module.
The entire exercise of generating electricity from solar energy is very capital expensive due to direct and indirect costs. Large land areas are required for setting-up photo-

voltaic power-plants because of low density of solar energy. A power plant of 1 MW peak-power capacity requires one hectare of land. Land has to be necessarily left vacant to avoid inter se shadowing of PV panels as sun transits the horizon. Laying special power-lines to connect distant 24X7 power-grids also adds to capital costs. Basic costs of installing photo-voltaic power systems per se are in any case high.
In the final analysis, despite the, abundance of solar energy in tropical countries such as India, and the many promotional incentives by the government, use of solar energy for power generation remains limited due to various aforementioned factors including low density of solar energy, its variability through the year, low efficiency of conversion of solar energy by PV panels, high capital cost of PV panels and costs incurred in foundations and structures for mounting of PV panels.
SUMMARY OF THE INVENTION:
The instant invention obviates the drawbacks of existing prior art. The invention, using its diurnal three-step position tracker to enable long linear arrays of PV modules to follow the sun as it moves across the sky in 24 hours of the day improves the economic viability in a substantive fashion. By installing these systems at higher altitudes it additionally exploits the unique properties of solar energy as it falls on the earth and characteristics of PV cells vis-a-vis spectral sensitivity and operating temperatures and cutting-out of losses in solar energy as it traverses the increasingly dense atmospheric layers down to sea-level, improves their economic viability still further.
The present photo-voltaic invention is economical to install and maintain. Besides having a long life, it is reliable, efficient, does not pollute the environment and is cost effective to operate.
The instant invention provides a system for harnessing solar energy into electricity through a novel arrangement of PV panels and by exploiting the spectral response of PV panels to incident solar radiation at higher altitudes.
For the purposes of this invention "solar panels" and "solar modules" are used interchangeably.

OBJECT OF THE INVENTION:
The main object of the present invention is to provide a novel system to generate electricity from solar energy through a novel arrangement of PV panels to track the sun as it moves across the sky during day through its three-step diurnal tracker to increase the generating efficiency of PV panels and exploiting innate characteristics of solar radiation and spectral response of PV panels to solar radiation at higher altitudes
Another object of the present invention is to take advantage of many large man-made structures including dams and forts already erected for other purposes and use them for generation of PV power by mounting the arrays on existing dams or forts thereby saving large tracts of expensive land for photo-voltaic power generation.
Yet another object of the present invention is to provide a non-polluting system for efficient conversion of solar energy into electric power at reduced capital investment.
Accordingly, the instant invention provides for a novel system for generating electricity from solar energy through photo-voltaic (PV) panels by exploiting the spectral response of PV panels to incident solar radiation, and by using a diurnal three step position tracker, said system comprising of a plurality of linear arrays of photovoltaic (PV) panels (1), said PV panel being adequately spaced to avoid inter se shadows as they swivel, each said panel being swivelable on its longitudinal axis (2) on bearings (3) mounted on transverse beams (4,5), said transverse beams supported on spaced perpendicular structural members (6,7), said perpendicular structural members being further supported on pedestals situated on suitably oriented natural or man-made structures thereby reducing use of large tracts of land for power generation, an actuator (12) controlled by pre-programmed computer (13) wherein each PV panel is fitted with an integral crank (8), said crank being connected at the other end to the adjacent panels in the array on both sides through a pair of adjustable tie-rods (11) via ball-jointed end-connectors (9,10) to form a long train of inter-connected PV panels so that whenever tie-rod (11) at one end of the train is pulled/ pushed by actuator (12), all panels in the array swivel in synchronized fashion through equal angles enabling the said system to harness optimal solar energy.
BRIEF DESCRIPTION OF THE DRAWINGS:
Some preferred aspects of the invention are described with reference to the drawings. It is emphasised that the drawings are diagrammatic and not intended to be limitative of the invention.

Fig 1 depicts a linear array of PV panels and single-axis tracker. Legend used to describe the labels in figure 1: Linear array of sun-facing PV panels (1); Panel swivelable on its longitudinal axis (2); Bearings (3); Transverse beams (4 and 5); Transverse Beams 4 and 5 supported on perpendicular structural members (6 and 7); Integral crank arm (8); Ball-jointed end-connectors (9 and 10); Tie-rod (11); Actuator (12); Pre-programmed computer (13)
Fig 2 is a diagrammatic representation of a simple diurnal 3 position tracker which swivels the panels to 60°, 90° and 120° from vertical.
Fig. 3 depicts the Rows of linear arrays installed on a southwardly-facing mountain slope (for Northern hemisphere)
Fig. 4 depicts the Rows of linear arrays on the southwardly-facing inclined face of a dam or a hill fort (for Northern hemisphere)
Figure 5 is a graphical representation of the impact of intensity of solar energy.
Figure 6 is a graphical representation of the effect of cell temperature (ambient temperatures) on electrical power output of the cell.
Figure 7 is a graphical representation of the impact of higher UV content
Details of the device of the present invention are shown in Figures 1 to 4 of the drawings accompanying this specification.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE DRAWINGS:
The present invention utilizes the free and limitless energy of the sun for power-generation by using its diurnal three-step position tracker to enable long linear arrays of PV modules to follow the sun as it moves across the sky during 24 hours of the day to improve the economic viability of PV power installations in substantive fashion. By installing these systems at higher altitudes it additionally exploits the unique properties of solar energy as it falls on the earth, basic characteristics of PV cells vis-a-vis spectral sensitivity and operating temperatures and, cutting-out the losses in solar energy as it

traverses the increasingly dense atmospheric layers down to sea-level, the invention improves their economic viability still further.
The present photo-voltaic invention is economical to install and maintain. Besides having a long life, it is reliable, efficient, does not pollute the environment and is cost effective to operate.
Response of silicon-based solar PV cells to temperature, intensity and spectral composition of solar energy, though common knowledge is repeated in Figs. 5, 6 & 7 for ready reference.
As can be seen in Fig. 5, Power output of a PV cell (Amperes X volts), termed efficiency in common parlance, is directly proportional to the intensity of solar energy falling on the cell. Similarly, graphs in Fig 6 show that a drop of 10°C in the operating temperature of a PV cell increases its efficiency by 8% approx. The third set of graphs in Fig. 7 show how efficiency increases with shorter wavelengths of below lOOOnm. It is well known that UV content (shorter wavelengths) increase as we go higher.
Broad estimates previously done for the lower reaches of Himalayas in Himachal Pradesh, India shows that the intensity of absorption of solar energy for the 24-hour average intensity of solar energy in space is 1,300 watts/m2, at 2000 m is 1,000 watts/m2, and at sea-level is only 300 watts/m2., during summer months intensity of absorption is 600 watts/m2 and during winters it is 200 watts/m2. The rate of temperature drop with altitudes at Indian latitudes is 6°C per 100 m and the impact of the layer of dust is 15%.
Table 1 is an effort to estimate the composite impact of above-discussed factors of the instant invention of its tracking system, characteristics of PV cells and solar energy on the total efficiency of PV cells with altitude. Conversion efficiency of 20% at sea level increases by 50% at an altitude of just 500m above sea level through the use
Table 1

(Table Removed)

The present invention may be embodied in other specific forms without departing from the spirit of the central characteristics thereof. The present embodiments therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
All references cited in this application are incorporated herein by reference to the same extent as if each was specifically indicated as being incorporated by reference and to the extent that they provide materials and methods not specifically shown.

I claim:
1 A novel system for harnessing solar energy for power generation through photo
voltaic (PV) panels by using a three-step diurnal sun-tracker to exploit the
response of PV panels to incident solar radiation, said system comprising of
a plurality of linear arrays of photovoltaic (PV) panels (1), said PV panels being adequately spaced to avoid inter se shadows as they swivel to follow the sun,
each said panel swivelable on its longitudinal axis (2) on bearings (3) mounted on transverse beams (4,5), - said transverse beams supported on spaced perpendicular structural members (6,7),
said perpendicular structural members being further supported on pedestals situated on suitably oriented natural or man-made structures thereby reducing use of large tracts of land for power generation, an actuator (12) controlled by pre-programmed computer (13) wherein each said PV panel is fitted with an integral crank (8), said crank being connected at the other end to the adjacent panels in the array on both sides through a pair of adjustable tie-rods (11) via ball-jointed end-connectors (9,10) to form an extended train of inter-connected PV panels so that whenever tie-rod (11) at one end of the train is pulled/ pushed by actuator (12), all panels in the array swivel in synchronized fashion through equal angles enabling the said system to harness solar energy in optimal fashion.
2 A system as claimed in Claim 1 wherein the said diurnal three-step position
tracker swivels the said PV panels to 60 degrees, 90 degrees and 120 degrees from
vertical where 90 degree corresponds to 12 noon, said such 3-position tracking
reduces the loss in harnessing of incident sunlight on the said PV panels to below
3%.
3 A system as claimed in Claim 1 wherein the electric power generation efficiency is
raised still further in a significant fashion by installing of the said system at higher
altitudes and thereby harnessing higher intensity & availability and higher UV
component of solar radiation at higher altitudes and, exploiting the inherent
characteristic of higher efficiency of PV Cells at cooler temperatures which prevail
at higher altitudes.

4 A system as claimed in Claim 1 where the said actuator is controlled by preprogrammed computer wherein the said computer programme is linked to daily sunrise and sunset timing determinable in advance.
5 A system as claimed in claim 1 wherein the said actuator is a computer-controlled DC motor-driven low friction lead-screw.
6 A system as claimed in Claim 1 wherein the said installations are made on suitably oriented natural mountain slopes or man-made structures such as dams or hill forts.
7 A novel system for generating electricity from solar energy through photovoltaic (PV) panels by exploiting the spectral response of PV panels to incident solar radiation, and by using a diurnal three step position tracker, said system as herein described and illustrated by way of examples and the accompanying figures.