EXERGOECONOMIC EVALUATION OF A SOLAR THERMAL POWER PLANT

The second law of thermodynamics combined with economics represents a very powerful tool for the systematic study and optimization of energy systems. This combination forms the basis of the relatively new field of thermoeconomics (exergoeconomics). This approach allows the monetary evaluation of costs caused by irreversibilities (exergy losses) as well as comparisons between these costs and the investment and operating costs for each component of a power plant. A 35MW solar thermal power plant has been analyzed with the aid of the exergoeconomics. It is found that in the reheater, heat exchanger and pumps it will be profitable to reduce exergy losses even by increasing the capital costs. Whereas it will be profitable to reduce capital cost in feed water heaters (no. 1, 2 and 3) by compromising with exergy losses. Most crucial component is the solar collector field where exergy losses are severe and it requires efficient collector design. Unfortunately not much could be done at the moment for the collectors. Its fate will depend on the advancements in collector technology. The analysis permits identification and evaluation of inefficiencies in the plant and opportunities for improvement in the plant components.