2.4 Other Classifications of Cogeneration Systems
Cogeneration systems are normally classified according to the sequence of energy use and the
operating schemes adopted. On this basis cogeneration systems can be classified as either a
topping or a bottoming cycle.
2.4.1 Topping cycle
In a topping cycle, the fuel supplied is used to first produce power and then thermal energy,
which is the by-product of the cycle and is used to satisfy process heat or other thermal
requirements. Topping cycle cogeneration is widely used and is the most popular method of
cogeneration.