- Email: [email protected]
Energy, Exergy, Economic and Environmental analysis of Photovoltaic Thermal Systems for Absorption Cooling Application
Available online at www.sciencedirect.com
ScienceDirect Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2017) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia
Energy (2017) 000–000 916–923 EnergyProcedia Procedia142 00 (2017) www.elsevier.com/locate/procedia
9th International Conference on Applied Energy, ICAE2017, 21-24 August 2017, Cardiff, UK
Energy, Exergy, Economic and Environmental analysis of Photovoltaic Systems for Absorption Cooling Application TheThermal 15th International Symposium on District Heating and Cooling Michael J. Adedejia, Tonderai L. Ruwab, Muhammad Abidc*, Tahir A. H. Ratlamwalad, Assessing the feasibility of using the heat demand-outdoor Mustafa Dagbasie
temperature function for a long-term district heat demand forecast Department of Energy Systems Engineering, Cyprus International University, Nicosia, Via Mersin 10, North Cyprus, a,b,c,e a,b,c,e
Turkey
a,b,c I. Andrić *, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc Shaheed Zulfikar Ali Bhutto Institute of Science and Technology, Clifton Campus, Karachi, Sindh, Pakistan dd
a
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
Abstract
In light of the popular gain of renewable energy sources and solar energy technologies in particular, photovoltaic thermal systems Abstract present an interesting approach towards cogeneration of electricity and heat. The extraction of heat from the photovoltaic array for use also serves the purpose of reducing the operating temperature of the solar cells to improve their power conversion efficiency. District networks are commonly addressed in the literature as oneanofabsorption the most system. effectiveThree solutions for decreasing the This studyheating analyzes the possibility of incorporating a PV/T system with different systems are greenhousethe gassingle emissions the effect building sector.effect These systems require investments which returned throughthat the the heat considered; effect,from double & triple absorption systemshigh driven by heat from theare PV/T. It is evident sales.effect Dueabsorption to the changed and coefficient building renovation policies, heat demand the future could decrease, triple coolingclimate system conditions has the highest of performance thus giving a greaterincooling benefit for the same prolonging the investment return period. input energy from the PV/T. main of this paper isby to Elsevier assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©The 2017 Thescope Authors. Published Ltd. ©forecast. 2017 The Authors. Published by Ltd. The district of Alvalade, in Lisbon (Portugal), used as aConference case study.onThe district is consisted of 665 Peer-review under responsibility of Elsevier thelocated scientific committee of the 9thwas International Applied Energy. Peer-review under of the scientific of the 9th International Conference Appliedhigh) Energy. buildings that varyresponsibility in both construction period committee and typology. Three weather scenarios (low, on medium, and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Keywords: Solar PV/T; Absorption cooling; Triple effect; Exergy. compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation 1.(the Introduction scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the to fossil A vast inacceptance concept of of the22-139h anthropogenic extent of season global (depending warming and climate change of due decrease the numberofofthe heating hours during the heating on the combination weather and fuel use, as well as the issue of energy security in light of dwindling fossil reserves, has seen a rapid increase in the renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the . Renewable energy sources international drive towards renewable and alternative energy sources in recent years coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, are and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: +90 392671 1111 Ext .2454; fax: +90 392 671 1122 Cooling. E-mail address: [email protected]
Keywords: Heat demand; Forecast; Climate change 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 9th International Conference on Applied Energy.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 9th International Conference on Applied Energy . 10.1016/j.egypro.2017.12.147
2
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
917
those sources that are easily replenished within reasonable time limits as compared to non-renewable fossil fuels which are currently depleting at a rate faster than they can ever be replaced. All renewable sources are directly or indirectly obtained from the sun except geothermal energy [1]. The sun supplies the earth with 174 PW of radiant power before attenuation and 51% of this reaches the earth’s surface [2]. Solar energy utilization involves the use of radiation from the sun in many ways, the most developed falling under two major categories; conversion of light energy directly to electrical energy – photovoltaics, and direct use of heat energy - solar thermal [3]. Photovoltaic (PV) is the science of conversion of solar radiation into direct current electricity. The basic conversion device is the PV cell. It employs semiconductors within which are valence band electrons which when exposed to solar radiation are able to move to the conduction band resulting in current generation [4]. One of the parameters that affect the PV cell performance is operating temperature [5]. An increase in temperature results in an increase in carrier recombination and thus causes less charge carriers to be available in the external circuit. Photovoltaic thermal (PV/T) systems are especially interesting as they combine the two conversion methods in cogeneration of electricity and heat [6]. Photovoltaic thermal technology (PV/T) involves the incorporation of a moving fluid extracting excess heat from the PV cell/panel/array. PV/T systems thus produce both direct current electricity and harvests solar radiation as heat [7]. This serves to increase system thermal efficiency, as well as improving PV power conversion efficiency by reducing cell operating temperature. Efficiency improvement is an important consideration in sustainable development. The increase in efficiency allows for a decrease in collector area required to achieve the same energy supply. It has also been reported that every degree rise in temperature of silicon solar cells sees a half of a percentage point decrease in efficiency [8]. Efficiency of photovoltaic panel systems has also been reported to decrease with module temperature, from 15% at 25°C to about 9% at 65°C [9]. PV/T systems gain more popularity points in this regard as the extraction of heat improves the efficiency of the system. Traditionally, vapor compression systems have been used for most cooling- above zero degrees- and refrigerationabove and below zero degrees- applications [10]. These systems, however, have a high energy demand. Most of such systems are also not sustainable as they use fossil fuel energy sources. This is where absorption cooling systems come into play, as they use low grade heat and can thus be driven from renewable and sustainable sources e.g. solar and geothermal [11]. The system works with two fluids, refrigerant and absorbent, of differing saturation temperature. The refrigerant is of lower saturation temperature, while the absorbent is of higher saturation temperature. Examples of refrigerant-absorbent mixtures commonly used are Ammonia-Water, Tridroxide-Water and lithium-bromide water [12]. Absorption refrigeration systems are grouped by simplicity from single effect, half effect to multiple effect systems. Single effect systems operate between 80oC-150oC, double effect systems operate between 120oC-150oC and triple effect systems operate between 180oC-230oC [13]. Notable research has been done on single and double effect absorption systems and these are widely understood [14]. In this paper, single, double and triple effect absorption cooling systems coupled to a PV/T collector are examined in a comprehensive energy and exergy analysis. 2. System Description Three different systems are considered; the single effect, double effect, & triple effect absorption systems driven by heat from the PV/T and a portion of the electrical output of the PV/T powers the pumps of the absorption systems while the rest can be used for residential applications. The single effect absorption cooling system (SEACS) consists of a generator, a condenser, an evaporator and an absorber. The double effect absorption cooling systems (DEACS) and the triple effect absorption cooling systems (TEACS) are modified to improve performance by adding a generator and a heat exchanger in the double effect system and two sets of generators and heat exchangers in the triple effect system. An ammonia-water solution is used in all the three systems. Fig 1 shows the integrated triple effect absorption cooling system with the PV/T. Heat from the PV/T is provided to the high temperature generator (HTG) where the strong solution coming from the absorber at state 28 is heated to leave as a weak solution at state 29 & an ammonia-water vapor with high concentration at state 30. Heat is absorbed by the system in the evaporator & passing air through the evaporator causes the cooling of the building. A more detailed system description can be found in the study of Ratlamwala et al 2011 [15].
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
918 3
Fig 1 Schematic diagram of the proposed PV/T with a TEACS.
3. Thermodynamic Analysis The energetic and exergetic equations for the analysis of each component is given followed by the economic and enviroeconomic (economic cost analysis). This study follows the model presented in [15] and due to the restriction on the number of pages of the paper, only a few important equations are presented here in this study. Power produced by the PV/T module is calculated by:
Wsolar c I c g A
(1)
The rate of heat transfer is:
Qsolar mwater where
C p.water UL
b U L l (hp ,2 g Z I U L Twater ,in T0 ) 1 exp mwater C p ,water
Z b g2 1 c hp,1g g c (c c )
The PV/T array area (A) used in this study is 360m2 and the solar radiation (𝐼𝐼 )̇ is 760 W/m2. Mass, energy, and exergy of components of the TEACS can be calculated from Table 1.
(2)
(3)
4
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
919
Table 1 Energy and Exergy balance for the TEACS components. Component
Energy Balance
Exergy Balance
HTG
𝑚𝑚̇ 28 ℎ28 + 𝑄𝑄̇ ℎ𝑡𝑡𝑡𝑡 = 𝑚𝑚̇ 29 ℎ29 + 𝑚𝑚̇ 30 ℎ30
𝐸𝐸𝐸𝐸̇28 + 𝐸𝐸𝐸𝐸̇𝐻𝐻𝐻𝐻𝐻𝐻 = 𝐸𝐸𝐸𝐸̇29 + 𝐸𝐸𝐸𝐸̇30
EVAPORATOR PUMP
𝑚𝑚̇ 10 ℎ10 + 𝑄𝑄̇ 𝑒𝑒𝑒𝑒𝑒𝑒 = 𝑚𝑚̇ 11 ℎ11 𝑚𝑚̇ 1 ℎ1 + 𝑊𝑊̇ 𝑝𝑝 = 𝑚𝑚̇ 2 ℎ2
𝐸𝐸𝐸𝐸̇ 10 + 𝐸𝐸𝐸𝐸̇ 𝑒𝑒𝑒𝑒𝑒𝑒 = 𝐸𝐸𝐸𝐸̇ 11
Equations for both the energetic & exergetic COPs are:
COPen,absp
Qeva Qhtg Wp
T Qeva 1 0 Teva COPex ,absp T Qhtg 1 0 Wp Thtg
(4)
(5)
The energetic & exergetic overall efficiency of each system can be calculated using:
ov ,en
Qeva Wsolar I b l Qaux
(6)
˙
ov ,ex
Ex eva Wsolar ˙
Ex solar Qaux
(7)
Exergy is defined as the maximum amount of work potential of a material or an energy stream in relation to the surrounding environment [16]. The energy of a fluid stream or exergy stream can be defined as: ˙
Ex mi ((hi h0 ) T0 ( si s0 )) i
(8)
where 𝐸𝐸𝐸𝐸̇𝑖𝑖 is the exergy of the fluid stream at temperature T, h is the enthalpy, s is the entrophy, ℎ0 & 𝑠𝑠0 are the enthalpy & entropy of the fluid at environmental temperature 𝑇𝑇0 (293.15oK). The rate of exergy of solar energy is calculated by: ˙ T Ex solar 1 0 I A Tsun
The purchase cost of the absorption system can be approximated by a function of cooling load [17]:
(9)
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
920 5
Zeq $ 1144.3 Qeva
0.67
(10)
where 𝑄𝑄̇𝑒𝑒𝑒𝑒𝑒𝑒 is the cooling load of the absorption system in kW. The purchase cost of a PV/T solar collector is a function of collector area that can be expressed as follows [17]:
Z PV /T $ 310nx ny lb
(11)
where 𝑛𝑛𝑥𝑥 and 𝑛𝑛𝑦𝑦 is the number of PV/T in series and parallel, 𝑙𝑙 and 𝑏𝑏 are the PV/T length and width respectively. The values of these parameters as used in the study are 100, 5, 1.2, & 0.6 respectively. The total cost rate of the system can be calculated using [18]:
Ctot $ / hr Z k
(12)
where 𝑍𝑍̇𝑘𝑘 is the cost rate of each component. The cost rate of each device in the system is determined as:
Z
Z k CRFΦ N 3600
(13)
where 𝑍𝑍𝑘𝑘 is the purchase cost of the 𝑘𝑘 𝑡𝑡ℎ component, and 𝐶𝐶𝐶𝐶𝐶𝐶 is the capital recovery factor. Also, 𝑁𝑁 is the annual number of operating hours for the unit, and Φ is the maintenance factor, which is often 1.06. The CO2 mitigation per annum can be estimated as:
CO 2
CO Eoverall 2
103
(14)
where 𝜙𝜙𝐶𝐶𝐶𝐶2 is CO2 mitigation per annum (tCO2/annum), 𝜓𝜓𝐶𝐶𝐶𝐶2 is the average CO2 equivalent intensity for electricity generation from coal (2.0 kgCO2/kWh) and 𝐸𝐸̇𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 is the annual overall energy/exergy produced (kWh) from the hybrid PV/T array per annum. The environmental cost is then given as:
Z ZCO2 CO2 CO2
(15)
where 𝑍𝑍̇𝐶𝐶𝐶𝐶2 is the enviroeconomic (environmental cost) parameters of CO2 (mitigation price per annum) ($/annum) and 𝑍𝑍𝐶𝐶𝐶𝐶2 is the carbon price per tCO2 (14.5 $/tCO2) [18,19]. 4. Results
The results of the simulation of the three systems are presented in this section and a comparison of the results is carried out. The results obtained from the energy and exergy analyses of the systems are tabulated in Table 2. Fig 2 shows the effect of the generator load on the energetic and exergetic COPs at constant evaporator load for the 3 systems. For the SEACS, the energetic COP decreases from about 1.6 to 0.1 and the exergetic COP also decreases from about 0.6 to 0.1 for an increase in generator load from 100 kW to 250 kW. A similar pattern is observed in both the DEACS & the TEACS with energetic COPs decreasing from about 2.5 to 0.5 and about 3.2 to 0.7 respectively. Also, the exergetic COPs for the DEACS & the TEACS reduce from about 0.8 to 0.2 and about 1.1 to 0.4 respectively.
6
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
921
Table 2 Parameter values resulting from energy and exergy analyses of the 3 systems. Parameter
SEACS
DEACS
TEACS
𝑄𝑄̇𝑒𝑒𝑒𝑒𝑒𝑒 (kW)
110.0
206.7
265.4
𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒𝑒𝑒,𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
0.73
1.36
1.76
𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒𝑒𝑒,𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
0.30
0.45
0.74
𝜂𝜂𝑜𝑜𝑜𝑜,𝑒𝑒𝑒𝑒
0.25
0.43
0.53
𝜂𝜂𝑜𝑜𝑜𝑜,𝑒𝑒𝑒𝑒
0.16
0.21
0.24
1.97
2.13
2.21
𝜙𝜙𝐶𝐶𝐶𝐶2 (tCO2/annum)
1359
2326
2913
19700
33729
42234
̇ ($/hr) 𝐶𝐶𝑡𝑡𝑡𝑡𝑡𝑡
𝑍𝑍̇𝐶𝐶𝐶𝐶2 ($/annum)
Fig 3 displays the effect of the solar irradiation on the overall energetic and exergetic efficiencies for the 3 systems. The energetic overall efficiencies decrease from about 0.5 to 0.1, 0.7 to 0.3, & 0.9 to 0.35 in the single, double, & triple effect systems respectively. Likewise, the exergetic efficiencies decrease from about 0.23 to 0.11, 0.3 to 0.13, & 0.31 to 0.21 in the single, double, & triple effect systems respectively with increase in solar radiation from 500 to 1000 W/m2. These 2 figs indicate that for a fixed cooling load, provision of more energy to the system than is required results in degrading performance of the system as this extra energy is not required by the system to achieve its target. Also, the better performance of the integrated TEACS can be attributed to the fact that it operates at a higher temperature. The high temperature hot water drawn from the PV/T will cool down the PV/T thereby increasing the efficiency of the integrated system. Fig 4 shows the effect of solar radiation on the evaporator load and the total cost rate of the 3 systems at constant energetic COPs. It can be observed that for the SEACS, the cooling load decreases from about 160 kW to 60 kW while the total cost of the system decreases from about 2.05 $/hr to 1.9 $/hr with an increase in solar radiation from 500 to 1000 W/m2. For the DEACS, the cooling load decreases from about 250 kW to 170 kW while the total cost rate decreases from about 2.2 $/hr to about 2.05 $/hr. Finally, the cooling load and the total cost rate of the TEACS both decrease from about 340 kW to 200 kW and from 2.3 $/hr to 2.1 $/hr. This is because the reduced cooling capacity will lead to a reduction in cooling costs and ultimately a reduction in the total cost rate of each system. . 1.6
5 COPEN,teacs at Qeva=265.4 kW COPEX,teacs at Qeva=265.4 kW
4
COPEN,seacs at Qeva=110.0 kW
COPEN
3
COPEX,seacs at Qeva=110.0 kW
0.8
2 0.4
1
0 100
125
150
175
200
225
Qsolar (kW) Fig 2 Effect of the generator load on the overall COPs for the 3 systems.
0 250
COPEX
COPEN,deacs at Qeva=206.7 kW 1.2 COPEX,deacs at Qeva=206.7 kW
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
EtaOV,EN
2
0.5
EtaOV,EN,teas at Qeva=265.4 kW EtaOV,EX,teas at Qeva=265.4 kW
1.6
EtaOV,EN,deas at Qeva=206.7 kW
1.2
EtaOV,EN,seas at Qeva=110.0 kW EtaOV,EX,seas at Qeva=110.0 kW
EtaOV,EX,deas at Qeva=206.7 kW
0.4
0.3
0.8
0.2
0.4
0.1
0 500
600
700
800
900
EtaOV,EX
922 7
0 1000
I (W/m2)
Ctotal,teas at COPen=1.76 Ctotal,deas at COPen=1.36 Ctotal,seas at COPen=0.73 QE,teas at COPen=1.79 QE,deas at COPen=1.36 QE,seas at COPen=0.74
QE (kW)
400
300
2.4
200
100
0 500
Ctotal ($/hr)
Fig 3 Effect of Solar radiation on the overall energetic and exergetic efficiencies for the 3 systems.
2
600
700
800
900
1000
2
I (W/m ) Fig 4 Effect of solar radiation on the cooling load and the total cost rate for the 3 systems.
5. Conclusion Three integrated multigeneration systems were simulated using the EES software. The selected PV/T system can generate 150 kW of thermal energy for the absorption systems and 25.89 kW of electricity. A comparison of the results obtained from the simulation of the three systems shows that the integrated TEACS has the best performance with energetic and exergetic COPs of 1.76 & 0.74 respectively. The same pattern is observed for the overall energetic and exergetic efficiencies with the integrated TEACS obtaining 53% and 24% respectively, when intensity is 800 W/m2. Increasing the amount of solar radiation on the PV/T showed a decrease in the overall efficiencies of the three systems. This indicates that for a fixed cooling load an increase in solar radiation is not recommended for the performance of
8
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
923
the systems. The cooling production capacity of the system decreases with an increase in the high temperature generator load due to the relatively higher temperature ammonia refrigerant entering the evaporator. Based on the results obtained in this study, the integrated TEACS gives the best performance of the 3 systems. All the systems are however efficient multigeneration systems with impressive amounts of CO 2 mitigation. References [1] N L Panwar, S C Kaushik, and S Kothari, "Role of renewable energy sources in environmental protection: a review," Renewable and Sustainable Energy Reviews, vol. 3, no. 15, pp. 1513-1524, 2011. [2] Franchini, G, "A comparative study between parabolic trough and solar tower technologies in Solar Rankine Cycle and Integrated Solar Combined Cycle plants," Solar Energy, no. 98, pp. 302-314, 2013. [3] S A Kalogirou, Solar energy engineering: Processes and systems.: Academic Press, 2013. [4] M A Green, Solar cells: Operating principles, technology, and system applications., 1982. [5] G K Singh, "Solar power generation by PV (photovoltaic) technology: A review," Energy, no. 53, pp. 1-13, 2013. [6] A S Joshi, I Dincer, and B V Reddy, "Performance analysis of photovoltaic systems: A review," Renewable and Sustainable Energy Reviews, vol. 8, no. 13, pp. 1884-1897, 2009. [7] A A Hegazy, "Comparative study of the performances of four photovoltaic/thermal solar air collectors," Energy Conversion and Management, vol. 8, no. 41, pp. 861-881, 2000. [8] J S Coventry, "Performance of a concentrating photovoltaic/thermal solar collector," Solar Energy, vol. 2, no. 78, pp. 211-222, 2005. [9] J K Tonui and Y Tripanagnostopoulos, "Improved PV/T solar collectors with heat extraction by forced or natural air circulation," Renewable energy, vol. 4, no. 32, pp. 623-637, 2007. [10] M H Kim, J Pettersen, and C W Bullard, "Fundamental process and system design issues in CO2 vapor compression systems," Progress in energy and combustion science, vol. 2, no. 30, pp. 119-174, 2004. [11] I Dincer and S Dost, "Energy analysis of an ammonia water absorption refrigeration system," Energy Sources Part A: Recovery, Utilization, and Environmental Effects, no. 18, pp. 727-733, 1996. [12] O E, Gogus, Y Ataer, "Comparative study of irreversibilities in an aqua-ammonia absorption refrigeration system," International Journal of Refrigeration, no. 14, pp. 86-92, 1991. [13] P Srikhirin, S Aphornratana, and S Chungpaibulpatana, "A review of absorption refrigeration technologies," Renewable and sustainable energy reviews, vol. 4, no. 5, pp. 343-372, 2001. [14] F Ziegler, R Kahn, F Summerer, and G Alefeld, "Multi-effect absorption chillers," International Journal of Refrigeration, no. 16, pp. 301311, 1993. [15] I Dincer, M A Gadalla, and T A H Ratlamwala, "Performance assessment of an integrated PV/T and triple effect cooling system for hydrogen and cooling production," International journal of hydrogen energy, no. 36, pp. 11282-11291, 2011. [16] Y A Cengel and M A Boles, "Thermodynamics: An engineering approach," Sea, no. 1000, p. 8862, 1994. [17] A Al-Alili, Y Hwang, R Radermacher, and I Kubo, "A high efficiency solar air conditioner using concentrating photovoltaic/thermal collectors," Applied Energy, no. 93, pp. 138-147, 2012. [18] H Rabbani, "Modeling and Multi-Objective Optimization of a Photovoltaic-Thermal Based Multigeneration System," Faculty of Engineering and applied science, University of Ontario, Ontario, Masters Thesis 2015. [19] R Tripathi, G N Tiwari, and V K Dweivedi, "Overall energy, exergy and carbon credit analysis of N partially covered Photovoltaic Thermal (PVT) concentrating collector connected series.," Solar Energy, no. 136, pp. 260-267, July 2016.
ScienceDirect Availableonline onlineatatwww.sciencedirect.com www.sciencedirect.com Available Energy Procedia 00 (2017) 000–000
ScienceDirect ScienceDirect
www.elsevier.com/locate/procedia
Energy (2017) 000–000 916–923 EnergyProcedia Procedia142 00 (2017) www.elsevier.com/locate/procedia
9th International Conference on Applied Energy, ICAE2017, 21-24 August 2017, Cardiff, UK
Energy, Exergy, Economic and Environmental analysis of Photovoltaic Systems for Absorption Cooling Application TheThermal 15th International Symposium on District Heating and Cooling Michael J. Adedejia, Tonderai L. Ruwab, Muhammad Abidc*, Tahir A. H. Ratlamwalad, Assessing the feasibility of using the heat demand-outdoor Mustafa Dagbasie
temperature function for a long-term district heat demand forecast Department of Energy Systems Engineering, Cyprus International University, Nicosia, Via Mersin 10, North Cyprus, a,b,c,e a,b,c,e
Turkey
a,b,c I. Andrić *, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc Shaheed Zulfikar Ali Bhutto Institute of Science and Technology, Clifton Campus, Karachi, Sindh, Pakistan dd
a
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal b Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France
Abstract
In light of the popular gain of renewable energy sources and solar energy technologies in particular, photovoltaic thermal systems Abstract present an interesting approach towards cogeneration of electricity and heat. The extraction of heat from the photovoltaic array for use also serves the purpose of reducing the operating temperature of the solar cells to improve their power conversion efficiency. District networks are commonly addressed in the literature as oneanofabsorption the most system. effectiveThree solutions for decreasing the This studyheating analyzes the possibility of incorporating a PV/T system with different systems are greenhousethe gassingle emissions the effect building sector.effect These systems require investments which returned throughthat the the heat considered; effect,from double & triple absorption systemshigh driven by heat from theare PV/T. It is evident sales.effect Dueabsorption to the changed and coefficient building renovation policies, heat demand the future could decrease, triple coolingclimate system conditions has the highest of performance thus giving a greaterincooling benefit for the same prolonging the investment return period. input energy from the PV/T. main of this paper isby to Elsevier assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©The 2017 Thescope Authors. Published Ltd. ©forecast. 2017 The Authors. Published by Ltd. The district of Alvalade, in Lisbon (Portugal), used as aConference case study.onThe district is consisted of 665 Peer-review under responsibility of Elsevier thelocated scientific committee of the 9thwas International Applied Energy. Peer-review under of the scientific of the 9th International Conference Appliedhigh) Energy. buildings that varyresponsibility in both construction period committee and typology. Three weather scenarios (low, on medium, and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were Keywords: Solar PV/T; Absorption cooling; Triple effect; Exergy. compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation 1.(the Introduction scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the to fossil A vast inacceptance concept of of the22-139h anthropogenic extent of season global (depending warming and climate change of due decrease the numberofofthe heating hours during the heating on the combination weather and fuel use, as well as the issue of energy security in light of dwindling fossil reserves, has seen a rapid increase in the renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the . Renewable energy sources international drive towards renewable and alternative energy sources in recent years coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, are and improve the accuracy of heat demand estimations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: +90 392671 1111 Ext .2454; fax: +90 392 671 1122 Cooling. E-mail address: [email protected]
Keywords: Heat demand; Forecast; Climate change 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 9th International Conference on Applied Energy.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the scientific committee of the 9th International Conference on Applied Energy . 10.1016/j.egypro.2017.12.147
2
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
917
those sources that are easily replenished within reasonable time limits as compared to non-renewable fossil fuels which are currently depleting at a rate faster than they can ever be replaced. All renewable sources are directly or indirectly obtained from the sun except geothermal energy [1]. The sun supplies the earth with 174 PW of radiant power before attenuation and 51% of this reaches the earth’s surface [2]. Solar energy utilization involves the use of radiation from the sun in many ways, the most developed falling under two major categories; conversion of light energy directly to electrical energy – photovoltaics, and direct use of heat energy - solar thermal [3]. Photovoltaic (PV) is the science of conversion of solar radiation into direct current electricity. The basic conversion device is the PV cell. It employs semiconductors within which are valence band electrons which when exposed to solar radiation are able to move to the conduction band resulting in current generation [4]. One of the parameters that affect the PV cell performance is operating temperature [5]. An increase in temperature results in an increase in carrier recombination and thus causes less charge carriers to be available in the external circuit. Photovoltaic thermal (PV/T) systems are especially interesting as they combine the two conversion methods in cogeneration of electricity and heat [6]. Photovoltaic thermal technology (PV/T) involves the incorporation of a moving fluid extracting excess heat from the PV cell/panel/array. PV/T systems thus produce both direct current electricity and harvests solar radiation as heat [7]. This serves to increase system thermal efficiency, as well as improving PV power conversion efficiency by reducing cell operating temperature. Efficiency improvement is an important consideration in sustainable development. The increase in efficiency allows for a decrease in collector area required to achieve the same energy supply. It has also been reported that every degree rise in temperature of silicon solar cells sees a half of a percentage point decrease in efficiency [8]. Efficiency of photovoltaic panel systems has also been reported to decrease with module temperature, from 15% at 25°C to about 9% at 65°C [9]. PV/T systems gain more popularity points in this regard as the extraction of heat improves the efficiency of the system. Traditionally, vapor compression systems have been used for most cooling- above zero degrees- and refrigerationabove and below zero degrees- applications [10]. These systems, however, have a high energy demand. Most of such systems are also not sustainable as they use fossil fuel energy sources. This is where absorption cooling systems come into play, as they use low grade heat and can thus be driven from renewable and sustainable sources e.g. solar and geothermal [11]. The system works with two fluids, refrigerant and absorbent, of differing saturation temperature. The refrigerant is of lower saturation temperature, while the absorbent is of higher saturation temperature. Examples of refrigerant-absorbent mixtures commonly used are Ammonia-Water, Tridroxide-Water and lithium-bromide water [12]. Absorption refrigeration systems are grouped by simplicity from single effect, half effect to multiple effect systems. Single effect systems operate between 80oC-150oC, double effect systems operate between 120oC-150oC and triple effect systems operate between 180oC-230oC [13]. Notable research has been done on single and double effect absorption systems and these are widely understood [14]. In this paper, single, double and triple effect absorption cooling systems coupled to a PV/T collector are examined in a comprehensive energy and exergy analysis. 2. System Description Three different systems are considered; the single effect, double effect, & triple effect absorption systems driven by heat from the PV/T and a portion of the electrical output of the PV/T powers the pumps of the absorption systems while the rest can be used for residential applications. The single effect absorption cooling system (SEACS) consists of a generator, a condenser, an evaporator and an absorber. The double effect absorption cooling systems (DEACS) and the triple effect absorption cooling systems (TEACS) are modified to improve performance by adding a generator and a heat exchanger in the double effect system and two sets of generators and heat exchangers in the triple effect system. An ammonia-water solution is used in all the three systems. Fig 1 shows the integrated triple effect absorption cooling system with the PV/T. Heat from the PV/T is provided to the high temperature generator (HTG) where the strong solution coming from the absorber at state 28 is heated to leave as a weak solution at state 29 & an ammonia-water vapor with high concentration at state 30. Heat is absorbed by the system in the evaporator & passing air through the evaporator causes the cooling of the building. A more detailed system description can be found in the study of Ratlamwala et al 2011 [15].
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
918 3
Fig 1 Schematic diagram of the proposed PV/T with a TEACS.
3. Thermodynamic Analysis The energetic and exergetic equations for the analysis of each component is given followed by the economic and enviroeconomic (economic cost analysis). This study follows the model presented in [15] and due to the restriction on the number of pages of the paper, only a few important equations are presented here in this study. Power produced by the PV/T module is calculated by:
Wsolar c I c g A
(1)
The rate of heat transfer is:
Qsolar mwater where
C p.water UL
b U L l (hp ,2 g Z I U L Twater ,in T0 ) 1 exp mwater C p ,water
Z b g2 1 c hp,1g g c (c c )
The PV/T array area (A) used in this study is 360m2 and the solar radiation (𝐼𝐼 )̇ is 760 W/m2. Mass, energy, and exergy of components of the TEACS can be calculated from Table 1.
(2)
(3)
4
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
919
Table 1 Energy and Exergy balance for the TEACS components. Component
Energy Balance
Exergy Balance
HTG
𝑚𝑚̇ 28 ℎ28 + 𝑄𝑄̇ ℎ𝑡𝑡𝑡𝑡 = 𝑚𝑚̇ 29 ℎ29 + 𝑚𝑚̇ 30 ℎ30
𝐸𝐸𝐸𝐸̇28 + 𝐸𝐸𝐸𝐸̇𝐻𝐻𝐻𝐻𝐻𝐻 = 𝐸𝐸𝐸𝐸̇29 + 𝐸𝐸𝐸𝐸̇30
EVAPORATOR PUMP
𝑚𝑚̇ 10 ℎ10 + 𝑄𝑄̇ 𝑒𝑒𝑒𝑒𝑒𝑒 = 𝑚𝑚̇ 11 ℎ11 𝑚𝑚̇ 1 ℎ1 + 𝑊𝑊̇ 𝑝𝑝 = 𝑚𝑚̇ 2 ℎ2
𝐸𝐸𝐸𝐸̇ 10 + 𝐸𝐸𝐸𝐸̇ 𝑒𝑒𝑒𝑒𝑒𝑒 = 𝐸𝐸𝐸𝐸̇ 11
Equations for both the energetic & exergetic COPs are:
COPen,absp
Qeva Qhtg Wp
T Qeva 1 0 Teva COPex ,absp T Qhtg 1 0 Wp Thtg
(4)
(5)
The energetic & exergetic overall efficiency of each system can be calculated using:
ov ,en
Qeva Wsolar I b l Qaux
(6)
˙
ov ,ex
Ex eva Wsolar ˙
Ex solar Qaux
(7)
Exergy is defined as the maximum amount of work potential of a material or an energy stream in relation to the surrounding environment [16]. The energy of a fluid stream or exergy stream can be defined as: ˙
Ex mi ((hi h0 ) T0 ( si s0 )) i
(8)
where 𝐸𝐸𝐸𝐸̇𝑖𝑖 is the exergy of the fluid stream at temperature T, h is the enthalpy, s is the entrophy, ℎ0 & 𝑠𝑠0 are the enthalpy & entropy of the fluid at environmental temperature 𝑇𝑇0 (293.15oK). The rate of exergy of solar energy is calculated by: ˙ T Ex solar 1 0 I A Tsun
The purchase cost of the absorption system can be approximated by a function of cooling load [17]:
(9)
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
920 5
Zeq $ 1144.3 Qeva
0.67
(10)
where 𝑄𝑄̇𝑒𝑒𝑒𝑒𝑒𝑒 is the cooling load of the absorption system in kW. The purchase cost of a PV/T solar collector is a function of collector area that can be expressed as follows [17]:
Z PV /T $ 310nx ny lb
(11)
where 𝑛𝑛𝑥𝑥 and 𝑛𝑛𝑦𝑦 is the number of PV/T in series and parallel, 𝑙𝑙 and 𝑏𝑏 are the PV/T length and width respectively. The values of these parameters as used in the study are 100, 5, 1.2, & 0.6 respectively. The total cost rate of the system can be calculated using [18]:
Ctot $ / hr Z k
(12)
where 𝑍𝑍̇𝑘𝑘 is the cost rate of each component. The cost rate of each device in the system is determined as:
Z
Z k CRFΦ N 3600
(13)
where 𝑍𝑍𝑘𝑘 is the purchase cost of the 𝑘𝑘 𝑡𝑡ℎ component, and 𝐶𝐶𝐶𝐶𝐶𝐶 is the capital recovery factor. Also, 𝑁𝑁 is the annual number of operating hours for the unit, and Φ is the maintenance factor, which is often 1.06. The CO2 mitigation per annum can be estimated as:
CO 2
CO Eoverall 2
103
(14)
where 𝜙𝜙𝐶𝐶𝐶𝐶2 is CO2 mitigation per annum (tCO2/annum), 𝜓𝜓𝐶𝐶𝐶𝐶2 is the average CO2 equivalent intensity for electricity generation from coal (2.0 kgCO2/kWh) and 𝐸𝐸̇𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜 is the annual overall energy/exergy produced (kWh) from the hybrid PV/T array per annum. The environmental cost is then given as:
Z ZCO2 CO2 CO2
(15)
where 𝑍𝑍̇𝐶𝐶𝐶𝐶2 is the enviroeconomic (environmental cost) parameters of CO2 (mitigation price per annum) ($/annum) and 𝑍𝑍𝐶𝐶𝐶𝐶2 is the carbon price per tCO2 (14.5 $/tCO2) [18,19]. 4. Results
The results of the simulation of the three systems are presented in this section and a comparison of the results is carried out. The results obtained from the energy and exergy analyses of the systems are tabulated in Table 2. Fig 2 shows the effect of the generator load on the energetic and exergetic COPs at constant evaporator load for the 3 systems. For the SEACS, the energetic COP decreases from about 1.6 to 0.1 and the exergetic COP also decreases from about 0.6 to 0.1 for an increase in generator load from 100 kW to 250 kW. A similar pattern is observed in both the DEACS & the TEACS with energetic COPs decreasing from about 2.5 to 0.5 and about 3.2 to 0.7 respectively. Also, the exergetic COPs for the DEACS & the TEACS reduce from about 0.8 to 0.2 and about 1.1 to 0.4 respectively.
6
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
921
Table 2 Parameter values resulting from energy and exergy analyses of the 3 systems. Parameter
SEACS
DEACS
TEACS
𝑄𝑄̇𝑒𝑒𝑒𝑒𝑒𝑒 (kW)
110.0
206.7
265.4
𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒𝑒𝑒,𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
0.73
1.36
1.76
𝐶𝐶𝐶𝐶𝐶𝐶𝑒𝑒𝑒𝑒,𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎
0.30
0.45
0.74
𝜂𝜂𝑜𝑜𝑜𝑜,𝑒𝑒𝑒𝑒
0.25
0.43
0.53
𝜂𝜂𝑜𝑜𝑜𝑜,𝑒𝑒𝑒𝑒
0.16
0.21
0.24
1.97
2.13
2.21
𝜙𝜙𝐶𝐶𝐶𝐶2 (tCO2/annum)
1359
2326
2913
19700
33729
42234
̇ ($/hr) 𝐶𝐶𝑡𝑡𝑡𝑡𝑡𝑡
𝑍𝑍̇𝐶𝐶𝐶𝐶2 ($/annum)
Fig 3 displays the effect of the solar irradiation on the overall energetic and exergetic efficiencies for the 3 systems. The energetic overall efficiencies decrease from about 0.5 to 0.1, 0.7 to 0.3, & 0.9 to 0.35 in the single, double, & triple effect systems respectively. Likewise, the exergetic efficiencies decrease from about 0.23 to 0.11, 0.3 to 0.13, & 0.31 to 0.21 in the single, double, & triple effect systems respectively with increase in solar radiation from 500 to 1000 W/m2. These 2 figs indicate that for a fixed cooling load, provision of more energy to the system than is required results in degrading performance of the system as this extra energy is not required by the system to achieve its target. Also, the better performance of the integrated TEACS can be attributed to the fact that it operates at a higher temperature. The high temperature hot water drawn from the PV/T will cool down the PV/T thereby increasing the efficiency of the integrated system. Fig 4 shows the effect of solar radiation on the evaporator load and the total cost rate of the 3 systems at constant energetic COPs. It can be observed that for the SEACS, the cooling load decreases from about 160 kW to 60 kW while the total cost of the system decreases from about 2.05 $/hr to 1.9 $/hr with an increase in solar radiation from 500 to 1000 W/m2. For the DEACS, the cooling load decreases from about 250 kW to 170 kW while the total cost rate decreases from about 2.2 $/hr to about 2.05 $/hr. Finally, the cooling load and the total cost rate of the TEACS both decrease from about 340 kW to 200 kW and from 2.3 $/hr to 2.1 $/hr. This is because the reduced cooling capacity will lead to a reduction in cooling costs and ultimately a reduction in the total cost rate of each system. . 1.6
5 COPEN,teacs at Qeva=265.4 kW COPEX,teacs at Qeva=265.4 kW
4
COPEN,seacs at Qeva=110.0 kW
COPEN
3
COPEX,seacs at Qeva=110.0 kW
0.8
2 0.4
1
0 100
125
150
175
200
225
Qsolar (kW) Fig 2 Effect of the generator load on the overall COPs for the 3 systems.
0 250
COPEX
COPEN,deacs at Qeva=206.7 kW 1.2 COPEX,deacs at Qeva=206.7 kW
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
EtaOV,EN
2
0.5
EtaOV,EN,teas at Qeva=265.4 kW EtaOV,EX,teas at Qeva=265.4 kW
1.6
EtaOV,EN,deas at Qeva=206.7 kW
1.2
EtaOV,EN,seas at Qeva=110.0 kW EtaOV,EX,seas at Qeva=110.0 kW
EtaOV,EX,deas at Qeva=206.7 kW
0.4
0.3
0.8
0.2
0.4
0.1
0 500
600
700
800
900
EtaOV,EX
922 7
0 1000
I (W/m2)
Ctotal,teas at COPen=1.76 Ctotal,deas at COPen=1.36 Ctotal,seas at COPen=0.73 QE,teas at COPen=1.79 QE,deas at COPen=1.36 QE,seas at COPen=0.74
QE (kW)
400
300
2.4
200
100
0 500
Ctotal ($/hr)
Fig 3 Effect of Solar radiation on the overall energetic and exergetic efficiencies for the 3 systems.
2
600
700
800
900
1000
2
I (W/m ) Fig 4 Effect of solar radiation on the cooling load and the total cost rate for the 3 systems.
5. Conclusion Three integrated multigeneration systems were simulated using the EES software. The selected PV/T system can generate 150 kW of thermal energy for the absorption systems and 25.89 kW of electricity. A comparison of the results obtained from the simulation of the three systems shows that the integrated TEACS has the best performance with energetic and exergetic COPs of 1.76 & 0.74 respectively. The same pattern is observed for the overall energetic and exergetic efficiencies with the integrated TEACS obtaining 53% and 24% respectively, when intensity is 800 W/m2. Increasing the amount of solar radiation on the PV/T showed a decrease in the overall efficiencies of the three systems. This indicates that for a fixed cooling load an increase in solar radiation is not recommended for the performance of
8
Michael J. Adedeji et al. / Energy Procedia 142 (2017) 916–923 M. Adedeji et al/ Energy Procedia 00 (2017) 000–000
923
the systems. The cooling production capacity of the system decreases with an increase in the high temperature generator load due to the relatively higher temperature ammonia refrigerant entering the evaporator. Based on the results obtained in this study, the integrated TEACS gives the best performance of the 3 systems. All the systems are however efficient multigeneration systems with impressive amounts of CO 2 mitigation. References [1] N L Panwar, S C Kaushik, and S Kothari, "Role of renewable energy sources in environmental protection: a review," Renewable and Sustainable Energy Reviews, vol. 3, no. 15, pp. 1513-1524, 2011. [2] Franchini, G, "A comparative study between parabolic trough and solar tower technologies in Solar Rankine Cycle and Integrated Solar Combined Cycle plants," Solar Energy, no. 98, pp. 302-314, 2013. [3] S A Kalogirou, Solar energy engineering: Processes and systems.: Academic Press, 2013. [4] M A Green, Solar cells: Operating principles, technology, and system applications., 1982. [5] G K Singh, "Solar power generation by PV (photovoltaic) technology: A review," Energy, no. 53, pp. 1-13, 2013. [6] A S Joshi, I Dincer, and B V Reddy, "Performance analysis of photovoltaic systems: A review," Renewable and Sustainable Energy Reviews, vol. 8, no. 13, pp. 1884-1897, 2009. [7] A A Hegazy, "Comparative study of the performances of four photovoltaic/thermal solar air collectors," Energy Conversion and Management, vol. 8, no. 41, pp. 861-881, 2000. [8] J S Coventry, "Performance of a concentrating photovoltaic/thermal solar collector," Solar Energy, vol. 2, no. 78, pp. 211-222, 2005. [9] J K Tonui and Y Tripanagnostopoulos, "Improved PV/T solar collectors with heat extraction by forced or natural air circulation," Renewable energy, vol. 4, no. 32, pp. 623-637, 2007. [10] M H Kim, J Pettersen, and C W Bullard, "Fundamental process and system design issues in CO2 vapor compression systems," Progress in energy and combustion science, vol. 2, no. 30, pp. 119-174, 2004. [11] I Dincer and S Dost, "Energy analysis of an ammonia water absorption refrigeration system," Energy Sources Part A: Recovery, Utilization, and Environmental Effects, no. 18, pp. 727-733, 1996. [12] O E, Gogus, Y Ataer, "Comparative study of irreversibilities in an aqua-ammonia absorption refrigeration system," International Journal of Refrigeration, no. 14, pp. 86-92, 1991. [13] P Srikhirin, S Aphornratana, and S Chungpaibulpatana, "A review of absorption refrigeration technologies," Renewable and sustainable energy reviews, vol. 4, no. 5, pp. 343-372, 2001. [14] F Ziegler, R Kahn, F Summerer, and G Alefeld, "Multi-effect absorption chillers," International Journal of Refrigeration, no. 16, pp. 301311, 1993. [15] I Dincer, M A Gadalla, and T A H Ratlamwala, "Performance assessment of an integrated PV/T and triple effect cooling system for hydrogen and cooling production," International journal of hydrogen energy, no. 36, pp. 11282-11291, 2011. [16] Y A Cengel and M A Boles, "Thermodynamics: An engineering approach," Sea, no. 1000, p. 8862, 1994. [17] A Al-Alili, Y Hwang, R Radermacher, and I Kubo, "A high efficiency solar air conditioner using concentrating photovoltaic/thermal collectors," Applied Energy, no. 93, pp. 138-147, 2012. [18] H Rabbani, "Modeling and Multi-Objective Optimization of a Photovoltaic-Thermal Based Multigeneration System," Faculty of Engineering and applied science, University of Ontario, Ontario, Masters Thesis 2015. [19] R Tripathi, G N Tiwari, and V K Dweivedi, "Overall energy, exergy and carbon credit analysis of N partially covered Photovoltaic Thermal (PVT) concentrating collector connected series.," Solar Energy, no. 136, pp. 260-267, July 2016.