If the solar constant is 1.4 kW/m2, then the solar energy received by 1 m2 area in one hour is :

From the solar constant we deduce that

1.4 kW of power is incident upon every 1m2 of area.

i.e. the total energy incident in 1 hr over an area of 1 m2 will be

= 1.4 kW x 1 hr

(Since P=E/t or E=P x t)

Hence, energy = 1.4 kWh

Converting into Kj we get 5040 Kj)