Issn 0003-701X, Applied Solar Energy, 2009, Vol. 45, No. 2, pp. 96-98. Allerton Press, Inc., 2009

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ISSN 0003-701X, Applied Solar Energy, 2009, Vol. 45, No. 2, pp. 96–98. © Allerton Press, Inc., 2009.
Original Russian Text © A.A. Abdurakhmanov, A.Sh. Khodzhaev, M.A. Mamatkosimov, Zh.Z. Akhadov, 2009, published in Geliotekhnika, 2009, No. 2, pp. 37–41.
96
The exhaustion of the Earth’s natural resources that
is caused by increase of the population and high rates of
increase of consumption leads to the need to seek alter-
native solutions. First of all, this concerns the power
resources and provision of foodstuffs. Therefore, scien-
tists are more and more interested in the renewable
energy sources. It should be noted that solar energy is
global, that is, it can be captured and transformed at any
point of the Earth. However, solar energy has two sub-
stantial drawbacks: first, low specific density over the
Earth’s surface, much lower than for the traditional
energy sources; second, the intermittent nature of the
solar energy reaching the Earth due to its diurnal rota-
tion and the meteoroclimatic environmental conditions,
such as cloudiness and atmosphere transparency. These
drawbacks hamper any large scale solar energy applica-
tion, at least in the foreseeable future.
At the present stage of science and engineering
development, in order to increase solar energy density,
several optical systems intended to concentrate the
radiant flux are in use. The second drawback may be
removed by accumulating either the solar energy or the
transformed energy. However, raising the solar energy
density extends the process transformation chain and,
accordingly, decreases the economic indices. There-
fore, the costs of solar energy transformation to thermal
or electric energy are several times the cost of the pro-
duced energy. Because of this, at the present time solar
energy is considered to be supplementary to traditional
power, and requires for its application subsidies, tax
remissions, or mandatory legislation. From this point of
view, the solar energy transformation process using
combined, closed cycles [1] is of interest. The works
[2, 3] presented the results of fundamental studies in
this field that were conducted in the framework of the
Government Scientific and Engineering Program
(GSEP) between 2003 and 2008.
The present article considers the questions of the
implementation of the obtained results in developing a
pilot project to investigate the feasibility of replication
in the conditions of Uzbekistan in the countries of Cen-
tral Asia. The developed process makes it possible to
generate a mixture of steam with hydrogen mixture by
decomposing water thermally in the solar energy con-
centrator focal zone at about 800
°
C, as well as electric
and heat energy. The steam/hydrogen mixture is
directed to an electrolyzer, in which pure hydrogen is
produced at the expense of part of the generated electric
energy. The hydrogen produced is used, first, as energy
storage when sunlight is not available (at night, cloudi-
ness); second, the hydrogen is used independently as
fuel. We see that the technological cycle is closed.
In the framework of this problem, fundamental sci-
entific investigations were conducted on the 1000 kW
Big Solar Furnace (BSF) in Parkent (Tashkent Region).
The Uzbek Big Solar Furnace is practically identical
to that built in France (Odeillo) under the leadership of
F. Trombe [3] in the 60s of the last century. This is con-
firmed by the data of the comparison table. However,
there are some differences in the radiant flux density in
the focal zone, number of heliostats, focal zone location
height, and so on.
As a result of the fundamental investigations on the
Big Solar Furnace in the period from 2003 to 2008, the
process of the closed cycle for transforming solar