Describe "combined heat and power" (CHP) in boiler systems.

Combined heat and power (CHP) systems are specifically engineered to operate in a manner that maximizes energy efficiency by producing both electricity and useful thermal energy simultaneously from a single fuel source. This dual output significantly reduces energy waste, as the heat that is byproduct in traditional electricity generation is effectively utilized rather than released into the environment.

In a typical CHP configuration, while electricity is generated, the excess heat from the process can be used for space heating, hot water production, or even for industrial processes, thereby providing a more integrated and efficient use of energy resources. This system not only enhances overall energy efficiency but can also lead to reduced greenhouse gas emissions and lower energy costs for the user.

The other options do not accurately capture the essence of a CHP system, focusing either on singular processes or specific functions that do not encompass the dual-generating capability or energy efficiency of a CHP setup.