Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Design optimization and sensitivity analysis of a biomass-fired combined cooling, heating and power system with thermal energy storage systems Martina Caliano a, ⁎ , Nicola Bianco a , Giorgio Graditi b , Luigi Mongibello b a Dipartimento di Ingegneria Industriale (DII), Università di Napoli Federico II, Napoli, Italy b ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Portici Research Center, Portici (NA), Italy ARTICLE INFO Keywords: Biomass Combined Cooling, Heating and Power (CCHP) system Feasible investment cost Thermal energy storage Sensitivity analysis Cold thermal energy storage Design optimization ABSTRACT In this work, an operation strategy for a biomass-fired combined cooling, heating and power system, composed of a cogeneration unit, an absorption chiller, and a thermal energy storage system, is formulated in order to satisfy time-varying energy demands of an Italian cluster of residential multi-apartment buildings. This operation strategy is adopted for performing the economical optimization of the design of two of the devices composing the combined cooling, heating and power system, namely the absorption chiller and the storage system. A sensitivity analysis is carried out in order to evaluate the impact of the incentive for the electricity generation on the optimized results, and also to evaluate, separately, the effects of the variation of the absorption chiller size, and the effects of the variation of the thermal energy storage system size on the system performance. In addition, the inclusion into the system of a cold thermal energy storage system is analyzed, as well, assuming different possible values for the cold storage system cost. The results of the sensitivity analysis indicate that the most influencing factors from the economical point of view are represented by the incentive for the electricity gen- eration and the absorption chiller power. Results also show that the combined use of a thermal energy storage and of a cold thermal energy storage during the hot season could represent a viable solution from the economical point of view. 1. Introduction Biomass, particularly wood, used for heating, cooling and electricity generation is one of the biggest source of renewable energy in the EU and is expected to have a key role in the achievement of the 20% EU renewable energy target by 2020. Moreover, a sustainable use of bio- mass can give a great contribution in addressing concerns about climate change and security of energy supply, also supporting economic growth and development [1]. In the residential sector, biomass is usually used to feed small-scale stoves. However, its use in Combined Heat and Power (CHP) plants is demonstrated to have substantial benefits with respect to biomass-fired systems providing separate generation of power and heat, and its expansion is further promoted by the EU energy efficiency directive [2]. In the last years, many authors have studied biomass-based poly- generation systems, conducting economic, energetic and exergetic analyses, also aimed at the evaluation of such systems performance with respect to systems for separate generation. Maraver et al. [3,4] presented a review on the technologies involved in biomass-fired Combined Cooling Heat and Power (CCHP) systems, also evaluating their performance in comparison to stand-alone conventional systems. Huang et al. [5] analyzed the technical and economic performances of a small-scale biomass-fuelled CCHP plant using an organic Rankine cycle to provide electricity and heat for building use. Harrod et al. [6] evaluated the cost and energy savings obtained by using a biomass-fired Stirling engine as a part of a CCHP system for building use. Calise et al. [7] simulated dynamically and investigated a polygeneration system where a reciprocating engine fed by vegetable oil was included. Pfeifer et al. [8] investigated the feasibility of CHP facilities fuelled by biomass in the Republic of Croatia, by considering several costs of biomass, and investment costs of the CHP systems. Gholamian et al. [9] performed a comprehensive thermodynamic modeling and environmental impact assessment for a CHP plant, composed of a wood biomass-fuelled gas turbine and a S-CO 2 cycle coupled with a domestic water heater. Bor- sukiewicz-Gozdur et al. [10] analyzed three variants of the same CHP plant based on organic Rankine cycle and fuelled with sawmill waste, in Poland. Amirante and Tamburrano [11] analyzed the use of small combined cycles for simultaneous generation of heat and power from the external combustion of solid biomass and low quality biofuels. Wang et al. [12] analyzed the performance of a biomass CCHP system http://dx.doi.org/10.1016/j.enconman.2017.07.048 Received 20 April 2017; Received in revised form 17 July 2017; Accepted 23 July 2017 ⁎ Corresponding author. E-mail address: martina.caliano@enea.it (M. Caliano). Energy Conversion and Management 149 (2017) 631–645 0196-8904/ © 2017 Elsevier Ltd. All rights reserved. MARK