In sugar industries, reasonably large
quantities of steam at low pressure and temperature are required.
This is apart from the electrical and mechanical energy required
to drive various equipments. In
such cases, it is advantages to raise steam at higher pressure and
use the extra energy (in the form of pressure) to drive generators
for production of electricity. Such energy produced is incidental
to the systems requiring only marginal quantities (about 20
%) of additional fuel and this is known as COGENERATION.