How to Design Solar PV System
What is solar PV system?
Solar photovoltaic system or Solar power system is one of renewable energy system which uses PV
modules to convert sunlight into electricity. The electricity generated can be either stored or used
directly, fed back into grid line or combined with one or more other electricity generators or more
renewable energy source. Solar PV system is very reliable and clean source of electricity that can suit a
wide range of applications such as residence, industry, agriculture, livestock, etc.
Major system components
Solar PV system includes different components that should be selected according to your system type,
site location and applications. The major components for solar PV system are solar charge controller,
inverter, battery bank, auxiliary energy sources and loads (appliances).
• PV module – converts sunlight into DC electricity.
• Solar charge controller – regulates the voltage and current coming from the PV panels going to
battery and prevents battery overcharging and prolongs the battery life.
• Inverter – converts DC output of PV panels or wind turbine into a clean AC current for AC
appliances or fed back into grid line.
• Battery – stores energy for supplying to electrical appliances when there is a demand.
• Load – is electrical appliances that connected to solar PV system such as lights, radio, TV,
computer,
refrigerator, etc.
• Auxiliary energy sources - is diesel generator or other renewable energy sources.
Solar PV system sizing
1. Determine power consumption demands
The first step in designing a solar PV system is to find out the total power and energy consumption of
all loads that need to be supplied by the solar PV system as follows:
1.1 Calculate total Watt-hours per day for each appliance used.
Add the Watt-hours needed for all appliances together to get the total Watt-hours per day which
must be delivered to the appliances.
1.2 Calculate total Watt-hours per day needed from the PV modules.
Multiply the total appliances Watt-hours per day times 1.3 (the energy lost in the system) to get
the total Watt-hours per day which must be provided by the panels.
2. Size the PV modules
Different size of PV modules will produce different amount of power. To find out the sizing of PV
module, the total peak watt produced is needed. The peak watt (Wp) produced depends on size of the
PV module and climate of site location. We have to consider “panel generation factor” which is
different in each site location. For Pakistan, the panel generation factor is 3.43 (assumed). To determine
the sizing of PV modules, calculate as follows:
What is solar PV system?
Solar photovoltaic system or Solar power system is one of renewable energy system which uses PV
modules to convert sunlight into electricity. The electricity generated can be either stored or used
directly, fed back into grid line or combined with one or more other electricity generators or more
renewable energy source. Solar PV system is very reliable and clean source of electricity that can suit a
wide range of applications such as residence, industry, agriculture, livestock, etc.
Major system components
Solar PV system includes different components that should be selected according to your system type,
site location and applications. The major components for solar PV system are solar charge controller,
inverter, battery bank, auxiliary energy sources and loads (appliances).
• PV module – converts sunlight into DC electricity.
• Solar charge controller – regulates the voltage and current coming from the PV panels going to
battery and prevents battery overcharging and prolongs the battery life.
• Inverter – converts DC output of PV panels or wind turbine into a clean AC current for AC
appliances or fed back into grid line.
• Battery – stores energy for supplying to electrical appliances when there is a demand.
• Load – is electrical appliances that connected to solar PV system such as lights, radio, TV,
computer,
refrigerator, etc.
• Auxiliary energy sources - is diesel generator or other renewable energy sources.
Solar PV system sizing
1. Determine power consumption demands
The first step in designing a solar PV system is to find out the total power and energy consumption of
all loads that need to be supplied by the solar PV system as follows:
1.1 Calculate total Watt-hours per day for each appliance used.
Add the Watt-hours needed for all appliances together to get the total Watt-hours per day which
must be delivered to the appliances.
1.2 Calculate total Watt-hours per day needed from the PV modules.
Multiply the total appliances Watt-hours per day times 1.3 (the energy lost in the system) to get
the total Watt-hours per day which must be provided by the panels.
2. Size the PV modules
Different size of PV modules will produce different amount of power. To find out the sizing of PV
module, the total peak watt produced is needed. The peak watt (Wp) produced depends on size of the
PV module and climate of site location. We have to consider “panel generation factor” which is
different in each site location. For Pakistan, the panel generation factor is 3.43 (assumed). To determine
the sizing of PV modules, calculate as follows:
