Solar Panel System-2266383

Assume that the following electrical load, expressed in watts, requires the design and installation of a solar panel system with a yearly capacity of 4500 kWh or 4,500,000 Wh (12,330 Wh/day) with 400Wp PV modules.

LoadRated Power (W)Hours/dayProduct of rated power and Hours/day
Water pump90021800
Electric frying pan50021000
 5 LED lamps (@10W each)5010500
5 Ceiling fans (@ 5W)255125
Electric iron7001700
Washing machine50021000
Coffee maker2002400
Dish washer70032100
Gas Heated4002800
Air conditioner40052000
Total:4615 12,225

Total load is 12,225 Wh/day

  • The required wattage by solar panels system

12,225 Wh x 1.3 = 15892.5 Wh/day

Note: 1.3 is a factor utilized for energy lost in the solar system

  • The size of the solar panels

= 12.4 modules

The actual requirement of the panels is 12 modules

The system will be power by 12 modules of 400Wp PV modules

  • Inverter size

The total required wattage for the appliances is 4615W

Due to inverter losses, the inverter’s rating now needs to be 25% higher than the overall load.

= 4615 x 2.5 = 11537.5 W

  • Battery sizing

Total electrical appliances used = 12,225 Wh/day

Nominal battery voltage = 12V

Days of autonomy = 3 days

The battery should be rated 12V 1800 Ah for 3 days autonomy

  • Solar charge controller sizing

PV module specification

Pm = 400 Wp

Vm = 30.7 Vdc

Im =13.03A

Voc = 40.7A

Isc = 15.5A

Solar charge controller rating = (12 strings x 7.5 A) x 1.3 = 117A

So we used 117A

  • The series and parallel connection of modules

When solar cells are added in series, voltages are added. The current remains same. Power is product of voltage and current.

When solar cells are added in parallel, voltages remains same. The currents added. Power is product of voltage and current.

Five panels are connected in series while seven panels are connected in parallel.

VT = V1 + V2 + V3 …… = 30.7 x 5 =153.5V

IT = 13.03 X 7 = 91.21A

Power = VT x IT  = 153.5 x 91.21  = 14,000.735 W = 14kW