Transcript Slide 1

System Sizing
• Sizing methodologies
• Sizing calculations
Sizing Strategy
Sizing strategy starts at the load side and
proceeds backward to the array.
Interactive System Sizing
Interactive system sizing
is very flexible because
the utility can supply
extra energy to the
system loads and receive
excess energy from the
utility system.
Stand-Alone Systems
Stand-alone systems
must be carefully
matched to load
requirements to avoid
reducing load
availability or wasting
excess energy.
Load Analysis
A load analysis tabulates
the various kinds of loads
and their power and
electrical energy
requirements.
Kill A Watt Meter
Load power and energy
requirements can be
easily measured with
meters.
Load Requirements
Load requirements include the power demand and
electrical energy consumption for all the expected
loads in the system.
Total DC Energy Requirements
The total DC energy
requirement is
determined from the
requirements for the
DC loads (if any) plus
the requirements for
the AC loads, taking
inverter efficiency into
account.
Critical Design Analysis
A critical design analysis compares the load
requirements and isolation for each month to
determine the critical design month.
DC-System Voltage
DC-system voltage is
chosen in proportion
with the array size and
to keep the operating
current below 100 A.
Array Sizing Worksheet
The array sizing worksheet
uses isolation data and load
requirements to size the
array.
Actual Array Output
Actual array output is
often less than rated
output due to soiling
and high temperatures.
Array Configurations
Modules are configured
in series and in parallel to
match the array rated
capacity need to produce
the required output.