Assessment of the greenhouse gas emissions from cogeneration and trigeneration systems. Part II: Analysis techniques and application cases

This paper provides a set of specific examples to show the effectiveness of the trigeneration CO2emission reduction (TCO2ER) indicator proposed in the companion paper (Part I: Models and indicators) to assess the greenhouse gas (GHG) emission reduction from cogeneration and trigeneration systems. Specific break-even analyses are developed by introducing further indicators, with the aim of assessing the conditions for which different types of combined systems and conventional separate production systems are equivalent in terms of GHG emissions. The various emission indicators are evaluated and discussed for a number of relevant application cases concerning cogeneration and trigeneration solutions with different types of equipment. Scenario analyses are carried out to assess the possible emission reduction benefits from extended diffusion of cogeneration and trigeneration in regions characterized by different energy generation frameworks. The results strongly depend on the available technologies for combined production, on the composition of the energy generation mix, and on the trend towards upgrading the various generation systems. The numerical outcomes indicate that cogeneration and trigeneration solutions could bring significant benefits in countries with prevailing electricity production from fossil fuels, quantified by the use of the proposed indicators.