Question

Calculate the battery energy and solar panel power required for the DC loads of 500 Wh per day. Battery DoD is 80%, Battery losses are 15%, Controller losses are 5%, inverter losses are 15%, Solar radiation is 5.25 kWh/m2/day, Solar panel losses are 25%.
718 Wh, 180 W
656 Wh, 150 W
1050 Wh, 150 W
1148 Wh. 180 W​

Answer 1

Solar panel requirement = 150 W

Explanation:

DC Load = 500 Wh per day

Charge controller losses at load side = 5%

So 5% of 500 Wh = 25 Wh.

Battery output = 500 + 25 = 525 Wh

Battery capacity = Battery output / DOD = 525 / 50% = 525 / 0.5 = 1050 Wh

Battery losses = 15% of 525 Wh = 78.75 Wh

Input for Battery = 525 + 78.75 = 603.75 Wh

Charge controller losses at panel side = 5% of 603.75 Wh = 30.19 Wh

Output from solar panel = 603.75 + 30.19 = 633.94 Wh

Losses at panel = 25 % of 633.94 Wh = 158.48 Wh

Input at panel = 633.94 + 158.48 = 792.42 Wh

Solar Radiation = 5.25 kWh / m2 / day

Solar panel requirement = Input at panel / sunshine hours = 792.42 / 5.25 = 150.93 W ~ 150 W