2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
- 239 -
0
2
4
6
8
10
12
0
20
40
60
80
100 120
PVpower (kWp)
Cost (million baht)
PV array
G
WECS
G
Diesel generator
AC bus 230 V 50 Hz
Consumers
Bi-directional
inverter
Grid-tie
inverter
Battery bank
TYPE 9:
Data reader
wind speeds,
irradiation,
ambient
temperatures
and load
TYPE 180: Photovoltaic
array (with data file)
TYPE 90: Wind energy
conversion system
Type 175: Power
conditioning unit
TYPE 241: AC-coupling hybrid power systems controller
TYPE 240: bi-
directional inverter
TYPE 185: Quasi-
static SOC model
TYPE 120: Diesel
engine generator set
TYPE 242: SAHPS life
cycle cost analysis
Type 583: TRNOPT
Type 175: Power
conditioning unit
TRNSYS components written by the authors
TRNSYS components in the standard library
TABLE I
C
OST AND
S
PECIFICATIONS OF
E
ACH
C
OMPONENT
Component
Investment costs
O&M cost
Lifetime (years)
PV system
150 baht/W
0.06 baht/W/year
20
WECS system
160 baht/W
0.16 baht/W/year
10
Diesel genset
10 baht/W
7.2 baht/hour
15000 h
Battery bank
0.5 baht/Wh
0.05 baht/Wh/year
10
Bi-directional inverter
40 baht/W
0.04 baht/W/year
10
* Exchange rate 1 Euro = 42 Baht, 1 U$ = 30 Baht
We assume that all of the 283 PV modules of the solar
home systems are usable. We also assume that it is
possible to use the 5 kW now installed at the school.
Therefore, the first 39 kW PV modules are free because
they are recycled from existing projects on the island.
However, since their use requires expenditures for an
inverter and mounting structure, the first 40 kW PV array
costs about 50 baht/W. With an additional purchase of a
PV array, actually purchasing the modules, inverter and
mounting structure costs adds up to 150 baht/W.
Fig. 4. Cost curve of PV array for Koh Mak Noi village.
C. System configuration
In an AC-coupled system, electricity generation can
occur anywhere along the AC transmission system. Thus,
a PV array can be distributed in several different
locations in the village. For this reason, AC-coupled
systems are considered to be more flexible and
expandable. For the importance of future expandability,
the hybrid power systems at Koh Mak Noi village are AC
coupled systems. This system consists of a PV array,
wind turbine, battery bank, inverter, controller and other
accessory devices. A schematic diagram of the basic
hybrid power system is shown in Fig. 5.
An overview of the TRNSYS components (TYPEs)
required to run the simulation of the reference system is
provided in Fig. 6. All the TRNSYS simulations TYPEs
used in this study include a photovoltaic array (TYPE
180: photovoltaic array (with data file)), wind turbines
(TYPE 90: wind energy conversion system), diesel
generator (TYPE 120: diesel engine generator set),
battery storage (TYPE 185: quasi-static SOC model),
static converters (TYPE 175: power conditioning unit)
and TRNSYS Optimizer (Type 583: TRNOPT). For a
more detailed description, we refer the reader to the
TRNSYS manual. The bi-directional converters (TYPE
240: bi-directional inverter), controller (TYPE 241: AC-
coupling hybrid power systems controller) and life cycle
cost analysis (TYPE 242: SAHPS life cycle cost
analysis) were developed and added in as TRNSYS
component models. All of the developed component
models presented here have been tested and verified
against measured data from the reference site.
Fig. 5. Schematic diagram of the AC-coupled hybrid power system
optimization model.
Fig. 6. The TRNSYS components of the AC-coupled SAHPS.
D. Optimization problem:
The objective function: The objective function to be
minimized is the life cycle cost of the system (baht), which
includes the costs of the investment plus the discounted
present values of all future costs throughout the total life
of the installation. We assume that the life of the system
is the life of the PV panels, which are the elements that
have a longer life time:
