Microgeneration energy systems based on advanced energy conversion technologies are perceived as very promising future energy options to reduce fuel use and emission. Tri-generation systems capable of satisfying simultaneously heating, cooling and electric demands represent the most advanced concept, but require still major efforts to become commercially viable. One important question in this context is the energy effectiveness or energy relevance of these systems, which is the subject of this paper. The main focus here was on assessing low-temperature SOFC technology, but the methodology presented is applicable for generic microgeneration systems as well. The results of the analyses show that not only the performance parameters of the advanced energy systems but also the characteristics of the end-use application will determine whether tri-generation brings benefits over the reference systems (separate heat and power production) or not. 10 20% primary energy savings can easily be achieved and even higher with more efficient future fuel cells. However, when the centralized power plant efficiency approaches a 55-60% level much of these benefits will be lost. Another case of concern would be the heat utilization rate of microgeneration which should preferably be close to 100%. We also found that using heat-driven sorption cooling, technically quite attractive for fuel cells at high temperature, may not be well justified when comparing to a reference system with vapor compression refrigeration. Copyright (C) 2011 John Wiley & Sons, Ltd.