DESIGN OF SOLAR BASED PHOTOVOLTAIC WATER PUMPING FOR IRRIGATION USING SUN TRACKING SYSTEM

 Determine motor pump power

 Motor pump power is 2HP which is the same as 1492W, I want to design the system to be able to run for 8 hours during from morning the rising of the sun till evening when the sun is down.

Determine servo motor power needed.

>Mass of a single panel is 22kgs, the length of the panel is 1.5m and the width of the panel is 1m.

>Power of the motor. 

From the equation (newton 2nd law of motion) 

>F=ma

>m = 22kgs and a = 9.81m/s2

>F=22kg x 9.81m/s2

>F = 215.82N

The average insolation over a year’s average, which is obtained from table above as 5.1 KW/m2/day.

>panel generation factor is 0.61

>Energy lost in the system is 1.3

Amount of Solar power needed = total watt-hour×1.3(energy lost in system) ÷ (0.62 ×5.1) 

Solar power =((1492+0.525×8)×1.3)/(0⋅61×5.1)

=4989.5W ≈ 5000W

Selection of a light dependent resistor (LDR)

 >LDR datasheet specifications

 >Power dissipation at 30°C = 250mW

 >Current = 75mA

 >From voltage divider circuit

 >𝑉𝑜𝑢𝑡=(R/(LDR+R))𝑋 𝑉𝑖𝑛

 >Vout = 250mW/75 mA

 3.33𝑉=(10k/(LDR+10k))𝑋 5𝑉

 LDR = 4.99k ≈ 5kΩ