ESCO Combined Heat and Power (Cogeneration)

Question 1

Why can a well-matched CHP system reach total system efficiency of 65–80%?

Accepted Answer

It captures and uses heat that conventional power generation rejects

Answer

Central power plants reject about two-thirds of fuel energy as waste heat. CHP generates electricity on site and recovers that heat for steam, hot water or cooling, so much more of the fuel energy is used.

Question 2

What does 'spark spread' mean in CHP economics?

Accepted Answer

The difference between the value of purchased electricity and the cost of fuel to generate it on site

Answer

Spark spread compares the cost of buying grid electricity with the fuel cost of making it. A wide spread (expensive power, cheap gas) favors CHP.

Question 3

Which facility is generally the best fit for CHP?

Accepted Answer

A hospital with steady year-round electric and thermal loads

Answer

CHP pays back best with long run hours and a steady, coincident need for both electricity and heat. Hospitals, universities and 24/7 industrial plants fit that profile.

Question 4

In a trigeneration (CCHP) system, which equipment turns recovered heat into cooling?

Accepted Answer

Absorption chiller

Answer

Absorption chillers use heat (steam, hot water or exhaust) instead of electricity to drive the refrigeration cycle. That lets CHP waste heat cover summer cooling load.

Question 5

Which of these is NOT a common CHP prime mover?

Accepted Answer

Ground-source heat pump

Answer

CHP prime movers generate electricity: reciprocating engines, gas turbines, microturbines, steam turbines and fuel cells. A ground-source heat pump moves heat and does not generate power.

ESCO - Energy Service Company Practice Test

ESCO - Energy Service Company Practice Test

ESCO Combined Heat and Power (Cogeneration)