Overall power costs of the system can be calculated on the following assumptions:
|
System cost |
US$ 32000 (Hfl. 90000) |
|
System life-time |
6 yrs |
|
Interest rate |
10% |
|
Maintenance costs |
10 percent per year of initial investment 1/ |
|
Additional labour costs |
1 man-yr |
|
Coconut shell costs |
US$ 6.00/t |
|
Operation |
4000 h/yr |
Those assumptions lead to the following breakdown of annual costs:
|
Annual Capital charges 2/ |
US$ 7350 |
|
Maintenance |
3200 |
|
Additional Labour |
700 |
|
Lubricants |
1600 |
|
Fuel (140 ton coconut shell) |
840 |
|
Annual Cost |
US$ 13690 |
|
Energy produced (4000 h x 20 kW) |
80000 kWh |
|
Unitary cost |
0.171 US$/kWh |
Those costs compare favourably with a diesel generation system, for which the costs under comparable circumstances would be around 0.26 US$/kWh.
1/ Assumed
2/ Annual capital charges are calculated using the relationship:
in which:
C = capital costs
i = annual interest rate
t = lifetime of system
