Experimental investigation of a building integrated photovoltaic/thermal roof collector combined with a liquid desiccant enhanced indirect evaporative cooling system Mahmut Sami Buker ⇑ , Blaise Mempouo, Saffa B. Riffat Institute of Sustainable Energy Technology, University of Nottingham, Nottingham NG7 2RD, UK article info Article history: Received 11 February 2015 Accepted 8 May 2015 Keywords: Solar thermal roof collector Liquid desiccant dehumidification Indirect evaporative cooling Tri-generation Numerical model Energy analysis abstract Large consumption of limited conventional fossil fuel resources, economic and environmental problems associated with the global warming and climate change have emphasized the immediate need to transi- tion to renewable energy resources. Solar thermal applications along with renewable energy based cool- ing practices have attracted considerable interest towards sustainable solutions promising various technical, economic and environmental benefits. This study introduces a new concept on solar thermal energy driven liquid desiccant based dew point cooling system that integrates several green technolo- gies; including photovoltaic modules, polyethylene heat exchanger loop and a combined liquid desiccant dehumidification-indirect evaporative air conditioning unit. A pilot scale experimental set-up was devel- oped and tested to investigate the performance of the proposed system and influence of the various parameters such as weather condition, air flow and regeneration temperature. A cost effective, easy-to-make polyethylene heat exchanger loop was employed underneath PV panels for heat genera- tion. In addition, a liquid desiccant enhanced dew point cooling unit was utilized to provide air condition- ing through dehumidification of humid air and indirect evaporative cooling. The experimental results show that the proposed tri-generation system is capable of providing about 3 kW of heating, 5.2 kW of cooling power and 10.3 MW h/year power generation, respectively. The findings confirm the potential of the examined technology, and elucidate the specific conclusions for the practice of such systems. Ó 2015 Elsevier Ltd. All rights reserved. 1. Introduction Utilization of sunlight for cooling is a long-sought goal. As the demand for cooling is proportional to the solar intensity, thus the time of peak cooling need coincides with the time of maximum resource occurs. Given this relation, it is no doubt that there has been a considerable interest to produce economical solar cooling technologies. Heat-activated systems that mainly driven by heat input from solar thermal energy have been introduced allowing simultaneous production of heat and cooling/refrigeration [1]. Compared to the conventional vapour compression systems, ther- mally driven air-conditioning technique would be an effective alternative in terms of increasing primary energy savings with less power consumption and therefore less greenhouse gas emissions and hazardous materials and pollutants depleted to the environ- ment [2]. A number of experimental investigations have been introduced in the literature for solar cooling systems. Huang et al. [3] con- ducted an experimental study of solar heat driven ejector cooling system for cooling load of 3.5 kW and cooling time of 10 h within two locations; Taipei and Tainan, respectively. Bermejo et al. [4] investigated a hybrid solar/gas cooling plant composed of a double effect LiBr + water absorption chiller with cooling capacity of 174 kW, a linear concentrating Fresnel collector and direct-fired natural gas burner. Another experimental study was performed by Ge et al. [5] employing a two-stage solar driven rotary desiccant cooling system with newly developed silica gel-haloid composite desiccant to achieve reducing regeneration temperature and high energy performance. A solar electric-vapour compression refriger- ation system was tested by Bilgili [6]. Eicker et al. [7] developed and tested a new photovoltaic-thermal (PVT) system to produce both power and cooling energy for night radiative cooling of buildings. In addition, several studies have investigated the solar assisted liquid desiccant cooling systems. To name a few, Katejanekarn et al. [8] presented an experimental study of a solar-regenerated http://dx.doi.org/10.1016/j.enconman.2015.05.026 0196-8904/Ó 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +44 7874364852. E-mail addresses: Mahmut.Buker@nottingham.ac.uk, msbuker@gmail.com (M.S. Buker). Energy Conversion and Management 101 (2015) 239–254 Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman