1 (34) Biomass-fired combined heating, cooling, and power for small scale applications – A review Moritz Wegener a,b,* , Anders Malmquist a , Antonio Isalgué b , Andrew Martin a a Heat and Power Technology, Department of Energy Technology, KTH Royal Institute of Technology, Brinellvägen 68, 100 44 Stockholm, Sweden b Architecture & Energy, School of Architecture of Barcelona, UPC. Av. Diagonal, 649, 6th Floor, 08028 Barcelona, Spain * Corresponding Author: Tel.: +46 8 790 60 00 E-mail: mbgw@kth.se Declaration of interest: None Abstract The growing demand for energy and the accelerating threats from climate change call for innovative and sustainable solutions to decrease dependency on fossil fuels. Biomass-based, small-scale Combined Cooling, Heating and Power (CCHP) systems are one of these solutions, because they can satisfy the energy demands of the consumer with enhanced flexibility, lower losses, less costs and less environmental pollution as compared to centralized facilities. Due to recent advances in several scientific subfields with relevance to small-scale CCHP, a rapidly increasing amount of literature is now available. Therefore, a structural overview is essential for engineers and researchers. This paper presents a review of the current investigations in small-scale CCHP systems covering biomass-fired concepts and solar extensions. To this end, critical system components are described and analysed according to their specific advantages and drawbacks. Recent case studies have been collected and key findings are highlighted according to each type of prime mover. The results indicate a scientific bias towards the economic viability of such systems and the need for real-life and experiment system data. However, the potential of biomass-fired CCHP systems and of such systems with solar extensions has clearly been recognised. Based on the results, future policy implementations should focus on fostering such systems in areas with high energy costs and to increase energy resilience in developed regions. Additionally research and industry applying novel prime mover technologies should be financially supported. Keywords Small-scale CCHP, Trigeneration, biomass, bio-solar 1 Introduction To fuel the world’s rising demand for energy while also to slow down emissions of greenhouse gases, more efficient and more sustainable energy systems are necessary [1]. Combined Cooling, Heating and Power (CCHP) is a technology that aims to raise the energy efficiency of an energy system by using the electric as well as the thermal output for practical applications [2,3]. Most deployed CCHP systems involve centralized facilities with extensive heating and cooling networks supplying hundreds or thousands of industrial and residential consumers. However, the disadvantages of centralized energy systems are losses due to longer transfer distances, the inability to reply to the immediate demands of individual consumers and higher security risks should unexpected shutdowns occur [4]. Therefore smaller decentralized units, which serve the local demand for heat as well as for electricity, can be a more profitable and more efficient alternative to centralized facilities [5].