Modeling of a small parabolic trough plant based in direct steam generation for cogeneration in the Chilean industrial sector

The concentrated solar power technology used in schemes of cogeneration for the production of power and heat, or power and cooling is an interesting option to develop in Chile, mainly due to the high solar potential. Besides, cogeneration is an option to face the demand for energy in terms of electricity, industrial heat or cooling, which is increasing in Chile in recent years. A concentrated solar power cogeneration plant based in parabolic trough technology with a backup system of a biogas heater and a direct steam generation scheme is proposed. The cogeneration study considers two different plants, one for power and heat, and other for power and cooling, which were studied in Santiago, Chile. The results show a benefit in fossil fuels replacement when the cogeneration plant is compared to a conventional plant for production of industrial heat. In the case of cooling, electricity savings are achieved when the cogeneration plant is compared to a conventional vapor-compression system. The cooling demand can be supplied totally using an absorption chiller in the cogeneration scheme, reaching electricity energy saving of up to 99%. For cogeneration of power and heat the energy replacement in the industrial heat process are as minimum 69% depending on the demand and configuration of the plant, and can reach up to 100%. Finally, when the biogas heater is disconnected from the plant to consider a case only based in the concentrated solar power plant, the cogeneration scheme for cooling can reach an electricity saving of 4%. The cogeneration scheme for heat can reach an energy replacement of 14% as minimum.