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

 
Development of Autonomous Solar Hydrogen Power Plant 
of Capacity to 5 kW
 
A. A. Abdurakhmanov, A. Sh. Khodzhaev, M. A. Mamatkosimov, and Zh. Z. Akhadov
 
Institute of Materials Science “Physics-Sun” Scientific Production Association of Uzbek Academy of Sciences
Received February 17, 2009
 
Abstract
—The main results of developing a pilot project concerning the water thermal decomposition cycle at
700
°
C in a reactor located at the concentrator focus are presented. Steam is generated and the mixture of water
vapor with hydrogen is directed to a turbine with electrical generator; the turbine exhaust is used in the heat
supply system, from which it enters an electrolyzer, in which pure hydrogen is separated from the mixture. Part
of the electric power produced by the generator is used for the electrolysis process. This cycle was studied in
the period from 2003 to 2008 as a part of the fundamental solar furnace programs in Parkent. The goal of the
pilot project is to create a power plant with overall power output (electric energy, heat supply, hydrogen) up to
5 kW that is intended for the Uzbek rural regions. When implementing the project, developers will work out the
design of the components, conduct pilot operations, train the servicing personnel, and conduct a feasibility
study for replication of the unit.
 
DOI: 
10.3103/S0003701X09020066
 
SOLAR POWER PLANTS 
AND THEIR APPLICATION 

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APPLIED SOLAR ENERGY
Vol. 45
No. 2
2009
DEVELOPMENT OF AUTONOMOUS SOLAR HYDROGEN POWER PLANT
97
energy into hydrogen, electric energy, and heat energy
was developed. The process facilities including the
monitoring and control systems were worked out. Our
results obtained from the fundamental investigations of
the combined closed solar energy transformation cycle
are as follows:
—Several experimental mockups were developed to
study the combined cycles for the simultaneous produc-
tion of hydrogen, electric energy, and heat energy based
on the Big Solar Furnace. The system operation is
based on water thermolysis, electricity turbogenera-
tion, and steam generation.
—The hydrogen synthesis feasibility was experimen-
tally determined in the chemical cycles at the BSF focus
with the radiant flux density 
 
Q
= 240 to 400 kW/m
2
that
is available at 700
°
C and six atm pressure. This is
achieved when using only 28 of the 62 heliostats.
—The feasibility of the combined thermal transfor-
mation cycles with simultaneous production of hydro-
gen, electric energy, and heat was demonstrated exper-
imentally. It was shown that the effectiveness of this
combined cycle may substantially exceed the effective-
ness of the separate hydrogen production cycle (30 to
40%), and also the effectiveness of production of heat
energy (about 50%) and electric energy (about 20 to
30%); and in the combined cycle the efficiency will be
about 64% in relation to the energy incident on the
receiver.
—The hydrogen production efficiency may be the
same as for the industrial cycles, that is, about 40%,
what is the premise for organizing hydrogen production
on the solar facilities. The maximal mount of hydrogen
that can be produced on the BSF is about 30 to 40 cubic
meters per hour.
Figure shows the percentage distribution among the
various energy types of the solar radiation reaching the
steam boiler, where 
 
QH
is the energy used to produce
hydrogen, 
 
Q
 
el
is the energy used to produce electric
energy; 
 
Q
 
hs
is the energy used for the building heating
systems; and 
Σ
 
Q
 
hl
are the total heat losses.
The results of the fundamental investigations con-
ducted on the BSF made it possible to proceed with
developing a combined solar and hydrogen power com-
plex of practical significance. This project was sup-
ported by the Uzbek Academy of Sciences and was sub-
mitted for consideration in the competition of the Small
Grants Program of the Global Ecological Foundation of
Uzbekistan in the framework of the UN Development
Program.