RST050
INSTALLATION
&
USER
MANUAL
16
Solar Cell Sizing
The following exercise provides sample calculations for a typical installation where
power is provided only by a solar cell.
These calculations assume:
•
Nominal location Rockhampton, Queensland, Australia
•
Solar cell conversion efficiency 15%
•
22+2 operation (see above tables)
Using the approximate location of Rockhampton, of Latitude -24 / Longitude 150
yielded a worse case Insolation (kWh/m2/day) of 3.3 in May using the 10 Year
Average Minimum.
With a conversion efficiency of 15% this is approximately 500Wh/m
2
/day.
Total requirement is 180Wh/day.
Dividing the energy requirement by the available energy gives
180Wh/day / 500Wh/m
2
/day = 0.36m
2
.
(Note that this energy is only available for around 6 hours a day worst case (May)).
It is advisable to factor in a 50% margin for extra-ordinary weather conditions and cell
ageing. This yields a solar cell with an area of 0.54 square metres.
