The Sun's luminosity is 4 x 10^26 Watts which means it sends out 400 trillion trillion Joules every second, enough energy in one second to power the United States for over a million years. Of this radiation, the Earth intercepts about 1366 Watts per square meter (this is known as the solar constant. The amount of this that reaches the ground depends on local atmosphere and cloud cover but typically varies between 900 and 1100 Watts per square meter.

The Sun is a fairly "dim" star and many stars are 100's, 1000's even millions of times brighter. The stars are so far away however that the amount of energy impacting the Earth from these stars is negligible.

Cheers - David