Research Paper Techno-economic assessment of a renewable energy based integrated multigeneration system for green buildings Farrukh Khalid *, Ibrahim Dincer, Marc A. Rosen Clean Energy Research Laboratory (CERL), Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario L1H 7K4, Canada H I G H L I G H T S • New integrated renewable energy based multigeneration system for green building is proposed. • Energy and exergy efficiencies of the overall system and its subsystems are determined. • Economic analysis is carried out in terms of net present cost and cost of electricity. ARTICLE INFO Article history: Received 1 October 2015 Accepted 10 January 2016 Available online Keywords: Efficiency Exergy Green building Renewable energy Techno-economic assessment A B ST R AC T A multigeneration system, which consists of wind turbine, concentrated solar collector, organic Rankine cycle, and ground source heat pump, is proposed, analyzed and assessed energetically and exergetically for residential applications. The useful outputs of the system are electricity, hot water, heating and cooling. The proposed system is designed for a green building and evaluated with energy and exergy efficien- cies. The effects of varying several parameters on the energy and exergy efficiencies of the system are investigated. Furthermore, the levelized cost of electricity and net present cost are determined, and the proposed system is optimized based on these parameters. The optimization determines the net present cost to be $345,481 and the levelized cost of electricity to be $0.181/kWh. The energy and exergy effi- ciencies of the overall system are found to be 46.1% and 7.3%, respectively. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Global demand for energy is continually increasing over the long term. In the past 50 years, this demand has increased signifi- cantly. This increase in energy demand places pressure on the resources from which energy is derived, contributing to the deple- tion of those resources that are finite (e.g., fossil fuels) and most of this demand is currently met by fossil fuels [1]. Another problem with the use of fossil fuels is the emissions they produce, which lead to various environmental problems. As seen in Table 1, the global CO2 emissions from fossil fuels peaked in the year 2012. With the gradual depletion of conveniently available fossil fuel reserves and their environmental problems, people are seeking other energy sources which are sustainable as well as environmentally benign, like renewable energy sources. As stated by the International Energy Agency (IEA) [1], the energy produced by renewables in 2008 was around 7% of the total energy production in the world and that value is expected to reach 22% by the year 2035. This is just one example of studies that indicate there is a high expectation for renewables to play a major role in the energy supply mix [2]. In several countries (e.g., Germany), there are policy changes and programs being implemented to support and encour- age a switch to a renewable energy based economy. Nowadays, there are two preferred ways of utilising solar energy: solar photovol- taics for direct electricity production and solar thermal for heating, cooling and power production purposes. In addition, wind power applications have received increasing attention during the past decade, due to well-developed turbine technologies of various ca- pacities, ranging from a few watts to megawatts [3]. One potential way to improve the performance and reduce the environmental impact of residential energy systems is to use multigeneration systems instead of using single, co- and/or trigeneration systems. Multigeneration systems are taken here to be * Corresponding author. Tel.: +12899797036; fax: +1-905-721-3370. E-mail address: farrukh.khalid@uoit.ca (F. Khalid). Table 1 CO2 emissions worldwide in 2012. Source CO2 emissions (Mtoe) Fraction of CO2 emissions (%) Fossil Fuels 31575 99.50 Others 158 0.50 Total 31734 100.00 Source: Reference 1. http://dx.doi.org/10.1016/j.applthermaleng.2016.01.055 1359-4311/© 2016 Elsevier Ltd. All rights reserved. Applied Thermal Engineering 99 (2016) 1286–1294 Contents lists available at ScienceDirect Applied Thermal Engineering journal homepage: www.elsevier.com/locate/apthermeng