According to the principle of "higher price for better quality"

the relationship between economic cost of product's unit exergy flow(Ci) in multiple co-generation system and energy quality factor of the said exergy flow(λi) has been put forward as in the following:Ci=beλi

it is called as "energy quality factor method" for short

improving and perfecting the matrix mode of economic cost analysis for product's unit exergy flow in the multiple co-generation system.Through practical examples

the economic cost of product's unit exergy flow in multiple co-generation system has been obtained by calculation according to the energy quality factor method

and a comparison with result obtained from the principle of "product equivalence" being made.It shows that the economic cost of product's unit exergy flow determined according to the energy quality factor is more appropriate.