Erratum to: Tackling environmental impacts in simple trigeneration systems operating under variable conditions

Abstract

Purpose Environmental concerns have been a growing issue when planning energy supply systems for buildings, as the energy demands (presenting seasonal and daily variations) represent one of the most energy-intensive consumptions in industrialized societies. The optimal operation corresponding to different energy demands of a trigeneration system was analyzed by an integrated methodology combining Thermoeconomic analysis and life cycle assessment, in order to adequately allocate the energy resources and the generated environmental loads to the different energy services produced. Methods Thermoeconomic analysis, which is usually used to allocate energy and economic costs, is herein applied to the evaluation of environmental costs and distribution of resources throughout the trigeneration system. Attention is focused on the correct allocation of energy resources and environmental loads to internal flows and final products. Appropriate rules were established to calculate energy and environmental costs. Results and discussion Operation of the system considered the possibilities that surplus electricity could be exported to the national grid and part of the cogenerated heat could be wasted if this resulted in a decrease of operation costs and/or environmental loads. The results obtained show a low-cost and low-emission production with respect to the separate production in different operation modes. It was observed that, in specific periods, the trigeneration system operates wasting part of the cogenerated heat, and, in other periods, part of the electricity produced is exported to the electric grid. The trigeneration system operates in these modes because it results beneficial from environmental or economic viewpoints, achieving a lower economic cost or fewer CO2 emissions. Conclusions The methodology presented as well as the allocation method proposal were congruent with the objectives of installing trigeneration systems that supplied energy services with fewer emissions than those of separate production and of equally benefitting the consumers of heat, coolth (“coolth” is used as the noun form of “cool”; opposite of warmth. Not to be confused with cooling, which is the opposite of heating.) (alias cooling energy), and electricity.