The formula to calculate the Generator Efficiency (Egen) is:
\[ Egen = \frac{O}{O + L} \times 100 \]
Where:
Let's say the generator output (O) is 500 units and the generator losses (L) are 50 units. Using the formula:
\[ Egen = \frac{500}{500 + 50} \times 100 = 90.91 \]
So, the Generator Efficiency (Egen) is 90.91%.