Small Rooftop Solar Power Plant Calculation
Rooftop solar is increasingly cost-effective for home owners, business owners, and their communities. Reductions in technology prices, innovative financing, and growing networks of solar installers and financial partners all helped drive down the prices for household systems in India.
The falling price of rooftop PV systems results from improvements in the technology and economies of scale among manufacturers.
Many home owners and businesses are taking advantage of third-party ownership options. Under solar leases or power purchase agreements, electricity customers typically pay little or nothing up front for rooftop systems, then get electricity from the systems over a long period. The falling prices and innovative financing structures mean that rooftop solar is more broadly available, and that the pool of customers comes from increasingly diverse economic backgrounds.
How to design of your rooftop power plant?
Step – 1
Load Calculate
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Application
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Load (Watt)
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No
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Hours of Use
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Wh/Day
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Total Application Load(Lw)=
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H=
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Total Load in Wh/Day (EL)=
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Total Load in KWh/Day =
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Step – 2
SIZING AND CHOICE OF ELECTRONIC COMPONENTS:
Once the load assessment process is complete, the next step is to choose suitable electronics for the PV system namely the Inverter and Charge controller. The capacity of these components depends on the voltage and current of the loads.
ESTIMATION OF REQUIRED INPUT ENERGY TO THE INVERTER:
calculate the input energy that must be fed to the inverter to get sufficient output energy to meet the demand of load.
Step 3:
DETERMINING THE SIZE OF BATTERY BANK:
BATTERY PARAMETERS & BATTERY SIZING:
In order to find out the size of the battery, we have to consider the following parameters of batteries.
• System Voltage and Ampere-hour capacity of the battery
• Depth of Discharge (DoD)
• No. of days of autonomy
ESTIMATING AMPERE-HOUR CAPACITY OF THE BATTERY:
The most common measure of battery capacity is Ah, defined as the number of hours for which a battery can provide a current equal to the discharge rate at the nominal voltage of the battery. Ah capacity of the battery can be calculated by dividing the energy input to the inverter (Output energy from battery) by System voltage.
ESTIMATION OF REQUIRED INPUT ENERGY TO THE BATTERY:
In practice, the battery efficiency may not be 100% and hence the entire energy supplied by the PV module may not be obtained from the output of battery bank.
PV Array Design
Say, this system will be install at Jaisalmer, Rajasthan (Latitude:26.9157487, Longitude:70.9083443)
Average Radiation kWh/m2/day: 5.89, Max in May: 7.52, Min in December: 3.97 kWh/m2/day
Max, Min and Average Temperature(°C/°F): 43, 30, 38 in May Month
Required PV Array Power (Application required)=
(TotalLoadinKWH/day)/(System’s efficiency factor X AverageSolarIrradiation) X PSI
Now make array as per inverter Specification
Operating Voltage Maximum Voltage and Minimum Voltage Range, check temperature co-efficient factor, MPPT Voltage range, Charging Current. It may be required to make trial and error method, change inverter VA for best suit.
