What is cogeneration described as in the material?

• A. Mopping up wasted energy
• B. Generating electricity only
• C. Reducing energy efficiency
• D. Producing energy from renewable resources

Answer: (A)

Cogeneration focuses on using the same energy input to produce both electricity and useful heat, capturing heat that would normally be wasted in the process. In the material, this is described as “mopping up wasted energy” because the heat from making electricity is not discarded but put to work for heating, industrial processes, or other needs. That approach boosts overall energy efficiency by getting more use out of the same fuel.

The other ideas don’t fit as well: generating electricity alone doesn’t utilize the accompanying heat; reducing energy efficiency is the opposite of what cogeneration does; and producing energy from renewable resources is about the source, not the combined production of electricity and heat. So describing cogeneration as mopping up wasted energy best matches its purpose.