Solar
Power System Major Components
In
stand-alone photovoltaic systems, the electrical
energy produced by the PV array can not always
be used when it is produced. Because the demand
for energy does not always coincide with its
production, electrical storage batteries are
commonly used in PV systems. The primary functions
of a storage battery in a PV system are to:
-
Energy Storage Capacity and Autonomy: to
store electrical energy when it is produced
by the PV array and to supply energy to electrical
loads as needed or on demand.
- Voltage
and Current Stabilization: to supply
power to electrical loads at stable voltages
and currents, by suppressing or 'smoothing
out' transients that may occur in PV systems.
- Supply
Surge Currents:
to supply surge or high peak operating currents
to electrical loads
All
stand-alone solar electric systems require battery
storage. Solar panels charge the batteries during
daylight hours and the batteries supply the
power when it is needed, often at night and
during cloudy weather.
The
two most common types of rechargeable batteries
in use are lead- acid and alkaline. Lead acid
batteries have plates made of lead, mixed with
other materials, submerged in a sulfuric acid
solution. Alkaline batteries can be either nickel-cadmium
or nickel-iron batteries. They have plates made
of nickel submerged in a solution of potassium
hydroxide.
Many
types and classifications of batteries are manufactured
today, each with specific design and performance
characteristics suited for particular applications.
Each battery type or design has its individual
strengths and weaknesses. In PV systems, lead-acid
batteries are most common due to their wide
availability in many sizes, low cost and well
understood performance characteristics. In a
few critical, low temperature applications nickel-cadmium
cells are used, but their high initial cost
limits their use in most PV systems.
OSS
represents Exide Technologies USA in Oman. Exide
Technologies, with operations in 89 countries,
is one of the world's largest producers and
recyclers of lead-acid batteries.
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