Adaptability of optimized cogeneration systems to deal with financial changes occurring after the design period

Cogenerations systems are energy efficient but when changes occur to the original design they can seem financially risky. Decreases in demand and increases in fuel prices can turn an optimal design into a failure, but that does not always have to be the case. The present article illustrates that cogeneration systems can be very robust to changes. A general cogeneration system is proposed consisting of one engine, three types of boilers and two types of chillers. This general system can use fuel or electricity as energy sources, as well as produce steam, chilled water and electricity for a commercial building. The objective function takes into account the initial investment and the operational life costs. Once the base case is optimized to the design parameters, we proceed with a series of case studies investigating the range of variations the system can support and continue to be the optimum. The major conclusions are the cogeneration system can stand an increase of up to 374% in the fuel tariff and an increase of up to 93% in the electricity tariff. Another conclusion is that cogeneration systems are robust in relation to variations in the fuel tariff in its second decade of operation.

► Cogeneration systems show an ability to stand increases of 374% in fuel prices.
► CHP systems operate in the same way even with increases of 93% in energy costs.
► CHP systems are robust to financial variations in the second decade of operation.