ISSN 0003-701X, Applied Solar Energy, 2018, Vol. 54, No. 2, pp. 126–130. © Allerton Press, Inc., 2018.
Original Russian Text © A.K. Saymbetov, M.K. Nurgaliyev, Ye. Tulkibaiuly, Yo.K. Toshmurodov, Ye.D. Nalibayev, G.B. Dosymbetova, N.B. Kuttybay, M.M. Gylymzhanova,
Ye.A. Svanbayev, 2018, published in Geliotekhnika, 2018, No. 2, pp. 58–64.
Method for Increasing the Efficiency of a Biaxial Solar Tracker
with Exact Solar Orientation
A. K. Saymbetov
*, M. K. Nurgaliyev
, Ye. Tulkibaiuly
, Yo. K. Toshmurodov
, Ye. D. Nalibayev
G. B. Dosymbetova
, N. B. Kuttybay
, M. M. Gylymzhanova
, and Ye. A. Svanbayev
Al-Farabi Kazakh National University, Kazakhstan
Physical–Technical Institute, Academy of Sciences of the Republic of Uzbekistan
Received January 17, 2018
Abstract⎯Modern solar follow-up systems make it possible to increase a solar cell’s efficiency and, as a
result, solar energy utilization. The paper considers modern solar follow-up methods and their operational
principles. Trackers are separated onto uniaxial and biaxial according to the plane which tracking occurs.
Biaxial trackers are the most efficient. The operational principles of active and passive trackers are studied. A
laboratory model of a biaxial solar tracker with precise solar orientation is described, based on an algorithm
for calculating the voltage with current sensors. The following are given in the paper: the current–voltage
characteristic obtained for different solar array positions and using trackers; the relationships between the
power and measured currents and voltages. The efficiency is calculated for different solar array positions and
using a tracker.
Up to the present, solar trackers are the most avail-
able devices for solar energy conversion and increasing
the conversion efficiency. In the present work, we
examine a biaxial solar tracker with a precise solar ori-
entation designed by authors.
The developed solar trackers have several advan-
tages and disadvantages. Usually, uniaxial trackers
increase solar energy generation by 27–32%, while
biaxial trackers add another 6% and increase genera-
tion ability by 35–40% with respect to an immobile
solar cell panel [1–3]. It is evident that the problem of
choosing a particular type of tracker adds cost for
maintenance work. The authors of  propose a labo-
ratory tracker that generates 42% more energy than
solar power plants with an immobile panel with
respect to the Sun.
Solar trackers or prediction systems are not critical
elements for photoelectric module operation. But if
there are no these systems, its efficiency decreases
greatly. When we design such type of power plant, it is
necessary to study properly the problems concerning
cost, reliability, power consumption and serviceability.
EXISTING AUTOMATIC SOLAR
Trackers or follow-up systems can operate as close
or open systems. In closed loop systems, feedback via
devices for light detection is used. Today, cloud mon-
itoring is used for collecting, positioning, and making
decisions about positioning of a photoelectric. For
operation of an open loop system, feedback is not nec-
essary; they operate based on mathematical algo-
rithms, which calculate astronomical coordinates for
positioning. In 1994, Poulek [7–9] developed a pas-
sive tracking system based on axial drives and a shape
memory alloy (SMA). The SMA drive can be easily
deformed at relatively low temperatures (lower than
70°C), which returns to its initial shape when heated
higher than a certain temperature. During heat cycles,
the SMA drive operates as a heat engine.
In 2004, Clifford and Eastwood developed an inex-
pensive passive system for tracking equatorial regions.
The amplification coefficient of this system is 23%
with respect to traditional fixed photoelectric mod-
ules. However, the proposed tracking system considers
only one axis of visible solar motion. Therefore, this
system is unable to compensate variations caused by
the angle of latitude as seasons change. The structure
of the passive tracking mechanism consists of two
bimetallic strips (plates) made of aluminum and steel,
placed symmetrically onto a wooden structure with
the horizontal axis as shown in Fig. 1.
In 1975, MacPhee presented one of the first track-
ing systems. It is an algorithm developed for calculat-
SOLAR POWER PLANTS
AND THEIR APPLICATION