FIELD OF THE INVENTION
The present invention relates to Solar photovoltaics and semiconductor
devices. In particular, the invention relates to mounting structure for solar
panels. More particularly, the invention relates to a mounting structure for
fixing solar panels on single axis active tracker.
BACKGROUND OF THE INVENTION
The generation capability of a photovoltaic panel is dependent on the
intensity of the solar radiation. The maximum power is generated when the
sunlight falls normal to the solar panel and no power is generated when the
sunlight falls parallel. The output current of solar panel increases with
irradiance whereas voltage remains relatively constant. In a fixed solar panel,
there is significant power loss during the day, as the panel is not always
perpendicular to the sun’s rays. A solar tracker system can keep the angle of
incidence within a certain range so as to maximize the generated power. The
present patent is a new concept of mounting structure for solar panels in
single axis active solar tracker, where need for any dedicated electrical or
optical sensor is eliminated. The mounting structure for solar tracker is
conceptualized in a way, that it creates a differential shadow on adjacent
panels.
Solar panels are fixed at the optimum angle for a particular latitude,
considering path of sun at that location over the year. Fixing PV modules at
the optimum angle yields an improvement as compared to flat mounted solar
panels. Solar trackers, on the other hand , adapt itself to the movement of
the sun and enhances the power producing capability of solar panels.

According to the prior art, the solar panels are fixed at same height in a
plane, on a mounting structure. For sun tracking dedicated electrical or
optical sensors are used in active trackers. These sensors significantly add to
cost of tracker and its maintenance. In this patent, a concept of fixing solar
panels, on a novel mounting structure is perceived. The mounting structure
for solar tracker is conceptualized in such a way, that solar panels in addition
to power generation, shall also act as sensor for active tracking system.
US 4476854 teaches that Large and small canisters can be provided at the
respective ends of a pivotable frame, and a conduit IS provided between the
canister and a gas spring fluid located in the large canister. When the sun is
not normal to the plane containing the canister, the near canister is shaded
from direct sunlight and the far canister is exposed. Volatile liquid is moved
from large to small canister and vice versa as per tilt angle.
US 4672191A discloses a device in which a shadow plate is mounted above
photo resistive sensors and different sets of sensors are mounted for
elevation and azimuth tracking on opposite ends. When the sun is not
normal to plane of tracker, it creates differential shadow on sensors. The
output is fed in to controller circuit and solar reflectors are aligned.
OBJECTS OF THE INVENTION
An object of the present invention is to propose a low cost solar panel
mounting structure for single axis active tracker.
Another object of the present invention is to propose a low cost solar panel
mounting structure providing feedback to the tracking system without the
need of any additional optical or electrical sensor.

SUMMARY OF THE INVENTION
An active tracker measures the strength of the sunlight and moves the array
such that it faces the brightest spot in the sky. In the traditional mounting
structure of panels for trackers, all solar panels are mounted at a same height
in a plane. In the present disclosure, a new concept of mounting solar panels
for single axis active tracker is provided. The mounting structure for solar
panels is conceptualized such that in addition to power generation, the
structure shall also act as sensor for active tracking system. The middle
section of the mounting structure is raised to a height with respect to
adjacent panels. When sun is not normal to the plane of the installed tracker,
the raised section of the mounting structure creates a differential shadow on
the adjacent panels. Since the electrical performance and characteristic
curves of solar panels are dependent on solar irradiance, identical solar
panels mounted adjacent to raised structure, produces different power. This
variation in power output of adjacent panels, due to differential shadow can
be used as feedback signal for single axis active tracker and the whole
assembly will move to such an angle where sun rays are again normal to all
the panel.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 Shows a schematic of the mounting structure of the tracker
assembly with the complete solar panels.
Figure 2 Shows the unique disposition of different panels on the
mounting structure.

DETAILED DESCRIPTION OF THE INVENTION
Solar cell industry is booming and a number of new industries are entering
into the business of installation and commissioning of solar power plants.
Reducing cost of operation and maintenance is the major challenge so as to
optimize profit. By enhancing the solar panel power, return on investment
can be increased. Market is flooded with different types of active solar
trackers which considerably increases the power output from panel but at the
same time due to additional component such as sensors, extra cost is
incurred. The reliability of such tracker is limited by frequent breakdown and
electrical circuit failure of sensors.
Considering all these circumstances, a new concept of mounting structure for
fixing solar panels on single axis active tracker has been conceived to
decrease the additional cost of sensors. The aim of this invention is to utilize
the existing components of tracker and reduce the cost and maintenance of
signal axis active tracker. In this patent, concept for mounting structure of
active tracker is conceptualized in such a way that in addition to power
generation, solar panels also act as a sensor and generate feedback signal to
active tracking system. A schematic for mounting structure of tracker is
shown in the figure 1. The section at the center of tracker is mounted on a
pole and the adjacent sections (figure 2: 1 & 3) are moveable. The height of
middle section with respect to adjacent structure can be varied and adjusted
by fly nut (Figure 1 & 2). When the plane of solar tracker is not normal to
sunrays, the panel mounted on section 2 create shadow on section 1 (refer
figure 2). The solar panel (3 of figure 2) receives more sunlight in comparison
to panel 1 of figure 2. The shadow region on panel 1 of figure 2 can be varied
by adjusting the height of Panel 2 of figure 2.

The electrical performance and characteristic curves of solar panels are
dependent on solar irradiance. The change in irradiance affects the module
current the most, as the current is directly dependent on the irradiance.
Whereas module voltage remains relatively constant. The shadow on panel 1
reduces the output current, resulting in lesser power output than solar panel
3. Therefore, this shadow creates difference in power output which in turn
act as feedback for the active tracker. The tracker then moves to such an
angle where sun rays are again normal to all the three panels thereby
resulting in active tracking and hence need for any dedicated electrical or
optical sensor can be eliminated.

WE CLAIM :
1. A low cost solar panel mounting structure, providing feedback to the
tracking system without adapting any additional optical or electrical
sensor. The panel mounting structure is configured to have a height
adjustable middle section to vary the height of the middle solar panel
with respect to adjacent solar panels. Wherein when the incidence of
sun rays are not normal to the plane of the installed sun tracker, a
differential shadow is created on adjacent Solar panels by the
middle solar panel, leading to generation of different solar power by
the adjacent identical solar panels. This variation in power output of
the adjacent solar panels is adopted as the feedback signal for the
tracker circuit. Which in turn realign, orientation of tracker to
such an angle where the sun rays fall normal on all the Solar panels.