2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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The annual electricity generation versus collector area
for various values of the evaporating temperature of the
ORC is shown in Fig. 5. It was found that the annual
electricity generation was increased with the increment of
collector area. The annual electricity generation from the
evacuated-tube solar
collector was also found to be
higher than the flat-plate solar collector. The maximum
yearly power generation at Chiang Mai was 21.7 MWh
while at Ubon Ratchathani was 20.91 MWh. For
evacuated-tube solar collector, the maximum yearly
power generation at Chiang Mai and Ubon Ratchathani
were 28.93 and 28.11 MWh, respectively. When the
collector area was below 500 m
2
, the annual electricity
generation was smoothly increased with the increment of
collector area. But when the area was over this value, the
storage size was increased to prevent boiling of water
then the warm-up period was longer. Therefore, as the
collector area increased the annual electricity generation
was slightly increased. The results were shown in Fig. 5.
Fig. 4. The mass of water in the thermal energy storage versus collector
area for various values of the evaporating temperature of the ORC.
Fig. 5. The annual electricity generation versus collector area for
various values of the evaporating temperature of the ORC.
C. Levelized Electricity Cost
The values of LEC versus collector area for various
values of the ORC evaporating temperature are also
shown in Fig. 6. It was found that the values of LEC from
the evacuated-tube solar collector were lower than that of
the flat-plate solar collector and the minimum values
could be obtained for each solar
collector
type.
In Table
III, at Chiang Mai and Ubon Ratchathani, the minimum
LEC values for the flat-plate solar collectors were 35.03
and 37.31 Baht/kWh, respectively while the evacuated-
tube solar collectors were 27.07 and 27.28 Baht/kWh,
respectively. Table IV shows a comparison of the SORC
at the optimum solar collector area for both solar
collector types.
Fig. 6. The values of levelized electricity costs versus collector area for
various values of the evaporating temperature of the ORC.
TABLE III
T
HE MINIMUM VALUES OF LEVELIZED ELECTRICITY COSTS
(LEC)
Province
Type of
solar
collector
c
A
(m
2
)
The
evaporating
temperature
of the ORC
(
o
C)
The
minimum
values of
LEC
(Baht/kWh)
Chiang Mai
Flat-plate
600
75
35.03
Evacuated-
tube
500
80
27.07
Ubon
Ratchathani
Flat-plate
700
75
37.31
Evacuated-
tube
500
85
27.28
TABLE IV
T
HE MINIMUM INVESTMENT COST
Data
Investment cost (Baht)
Chiang Mai
Ubon Ratchathani
Flat-plate
solar
collector
Evacuated
-tube
solar
collector
Flat-plate
solar
collector
Evacuated
-tube
solar
collector
1. Solar
collector
3,000,000
2,750,000
3,500,000
2,750,000
2. ORC,
generator and
1,000,000
1,000,000
1,000,000
1,000,000
