Combined financial and environmental optimization of a trigeneration system

This paper firstly studies the influence of variations in fuel tariffs and GHG emissions of the grid electricity on the financial and environmental metrics, demonstrating divergences when considered alone. Secondly, a combined economic and environmental objective function is proposed, yielding a good compromise between both concerns. Real data are available from a Brazilian Northeast building where electricity, heat (hot water), and cooling are important for comfort and well-being. When addressing the bicriteria optimization, consideration of 20% of one metric enormously improved the overall result, with only slightly worsening the other metric. This is possible because the optimization scheme can choose from a rich pool of physical and operational scenarios.