In the residential sector of Mexico, the most important energy demands are related to the supply of electricity and hot water. These demands can be met efficiently using cogeneration systems (Combined Heat and Power, CHP). However, the design of CHP systems involves problems related to technology selection, sizing and operation of the central CHP unit. To solve this problem, there has been used optimization algorithms that consider environmental parameters, usually related to ambient temperature, economic, as fuel costs or prices of electricity and operating, maintenance and capital costs of equipment and the energy demands of the end user. Traditionally, it was considered that these elements behave regularly over time. However, the reality is that these parameters fluctuate and the designer has no control over them.
One way to solve this problem is by using optimization formulations able to handle the uncertainty associated with these parameters. Therefore, this paper presents a methodology based on a mixed-integer nonlinear programming model that considers the selection of technologies, which include internal combustion engines, fuel cells, microturbines and Stirling engines, a thermal storage tank, an auxiliary water heating system using a conventional boiler, the optimal sizing of the system and the interactions of purchase - sale of energy with the grid of the local company to meet the energy demands of a housing complex. As design parameters under uncertainty there have been considered the ambient temperature, energy demand related to the floating population and local energy market prices. As objective function, there is considered a multi-objective scheme that allows to minimize the total annual cost of the system and secondly to minimize the generation of greenhouse gas emissions associated to fuel consumption.
As a case study there is considered a housing complex located in the center of Mexico with 1440 households. The results obtained under different scenarios show economic and environmental benefits in implementing CHP systems.