Solar Cell Design - Panasonic BP-5917C40 Technical Handbook

12. SOLAR CELL DESIGN

Solar cells are devices that convert light into electricity,
but they do not store electric power. In addition, since
the actual amount of power produced varies depending
on factors such as the installation conditions and
location, as well as the weather, there are a few
requirements which must be borne in mind when
designing a system. Power supply systems employing
solar cells generally fall into one of the following three
categories.
(1) Direct connection to load
(2) Paired with storage battery
(3) Paired with commercial power supply
12.1 Solar Cell Power Supply System Basic Configuration
(1) Direct Connection to Load
This type of configuration is suitable for applications
such as warehouse ventilation systems, car ventilators or
(2) Paired with Storage Battery (Direct load)
In this configuration the solar cell is paired with a
storage battery. It is suitable as an independent power
supply for applications such as lighting systems,
Solar cell
(3) Paired with Commercial Power Supply (Night
load)
This sort of configuration is suitable in cases where a
commercial power supply is needed to act as a backup
Solar cell
Panasonic
Solar cell
Diode to prevent reverse flow
Charge/discharge
control circuit
Diode to prevent reverse flow
Solar Cells Handbook, Page 39
Presented below are a few simple guidelines and
equations to aid in the selection of solar cells and
storage batteries, based on the basic system
configuration and the load presented by the equipment
to be driven. Panasonic has been conducting research on
solar cell power supply systems for many years and has
collected a voluminous amount of data on the subject.
Please consult your Panasonic representative for specific
design details.
irrigation pumps in which equipment is driven only
when there is illumination.
highway displays and communications equipment. Refer
to the Design Guide which follows for details on system
design.
Charge/discharge
control circuit
Storage
battery
when the solar cell alone is insufficient. As the actual
system design is quite complex, please consult
Panasonic.
Storage
battery
Load
Load
Inverter
Commercial
power supply
Load
August 1998