Solar Water System Conclusions

• Great portions of the total heating and cooling loads are satisfied by solar energy at the optimum conditions and the overall system efficiency is within the previously published results.

• The cost of unit energy for solar heating and cooling systems approximately equals to 68% of the corresponding cost of the conventional fuel at the current prices. This maximum energy is attained with a solar collector area of 38 m2.

• An annual solar savings of about $1900 is achieved at these optimum conditions which confirms the feasibility of solar heating and cooling systems in Kuwait climate.

• The avoided CO2 emission has been found to be equal to 9.7 tonne/year corresponding to a reduction cost of $10.3/tonne.

• The results of this study should encourage wide utilization of solar energy systems which will help in keeping our environment healthy and clean.


Ac Collector area (m2)

As Storage tank surface area (m2)

cp Specific heat of the water (J/kg K)

Solar energy investment cost which is directly proportional to collector

CC Cost of kW h generated using conventional electricity system ($)

CE Solar energy investment cost which is independent of collector area ($)

Unit cost of delivered conventional energy for the first year of analysis

Chc Cost of kW h generated using solar heating and cooling system ($)

CR Avoided cost or reduction cost ($)


Discount rate (%)


Avoided CO2 emission (tonne CO2)


CO2 emissions from conventional system (tonne/kW h)

Energy generation cost of the solar heating and cooling system


($/kW h)


CO2 emissions from solar heating and cooling system (tonne/kW h)


Solar fraction of space cooling


Solar fraction of domestic water heating


Plant emission factor (tonne CO2/kW h)


Solar fraction of space heating


Total solar fraction


Heat removal factor


Incident radiation on horizontal surface (W/m2)


Clearness index


Total load (kJ)


Life cycle savings ($)


Mass of the water in the storage tank (kg)


Factor relating life cycle fuel cost to first-year fuel cost savings

Factor relating life cycle by additional capital investment to initial




Annual power generation (kW)


Useful energy rate gained by the collector (W)


Ambient temperature (°C )


Inlet collector temperature (°C )

1 o

Outlet collector temperature (°C )

Temperature of the combined stream of water returning from the air


conditioner (°C )


Temperature of water in the energy storage tank (°C )


Collector overall heat loss coefficient (W/m2 K)


Storage tank heat transfer loss coefficient (W/m2 K)


Mass flow rate of water to the collector (kg/s)


Mass flow rate of water to the air conditioner or air heater (kg/s)


Mass flow rate of water to the service hot water system (kg/s)


Wind speed (m/s)


Space cooling efficiency


Collector efficiency


Domestic water heating efficiency


Space heating efficiency


Total system efficiency


Transmittance-absorbance product


Belarbi, R, Ghiaus, C, Allard, F (2006) Modeling of water spray evaporation: Application to passive cooling of buildings. Solar Energy 80: 1540-1552.

Bo Nordell, B, Hellstrom, G (2000) High temperature solar heated seasonal storage system for low temperature heating of buildings. Solar Energy 69: 511-523. Breesch, H, Bossaer, A, Janssens, A (2005) Passive cooling in a low-energy office building. Solar Energy 79: 682-696.

Bruno, JC, Fernandez, F, Castells, F (1996) Absorption chillers integration in a combined heat and power. Solar Energy 2: 759-767.

Ciampi, M, Leccese, F, Tuoni, G (2003) Ventilated facades energy performance in summer cooling of buildings. Solar Energy 75: 491-502.

Duffie, JA, Beckman, WA (1991) Solar Engineering of Thermal Process. Wiley Interscience, New York.

Energy Information Administration (1999) Emissions of Greenhouse Gases in the United States 1998" Chapter 2, "Carbon Dioxide Emissions," DOE/EIA-0573 (98), Washington, DC.

Garg, HP (1987) Advances in Solar Energy Technology. D. Reidel Publishing Company, Holland.

Ghoneim, AA, Fisch, N, Ammar, AS, Hahne, E (1993) Design of a Solar Heating System for Alexandria, Egypt. Renewable Energy 3: 577-583.

Gordon, JM, Choon, K (2000) High-efficiency solar cooling. Solar Energy 68: 23-31. Herold, KE, Radermacher, R, Klein, SA (1996) Absorption Chillers and Heat Pumps. CRC Press. Inc., ISBN 0-08493-9427-9

Klein, SA, et al. (1993) TRNSYS, A Transient Simulation Program, University of Wisconsin-Madison, version 13.1.

Kuwait Institute for Scientific Research (2006) Personal Communication.

Lof, GOG, Tybout, RA (1974) The design and cost of optimized systems for residential heating and cooling by solar energy. Solar Energy 16: 9-18.

Lunde, PJ (1978) Prediction of monthly and annual performance of solar heating systems. Solar Energy 20: 283-287.

Mathioulakis, E, Belessiotis, V (2002) A new heat-pipe type solar domestic hot water system. Solar Energy 72: 13-20.

Mesquita, LCS, Harrison, SJ, Thomey, D (2006) Modeling of heat and mass transfer in parallel plate liquid-desiccant dehumidifiers. Solar Energy 80: 1475-1482. Nakahara, N, Miyakwa, Y, Yamamoto, M (1977) Experimental study on house cooling and heating with solar hnergy using flat plate collector. Solar Energy 19: 657-662.

Narula, RG, Wen, H, Himes, K (2002) Incremental cost of CO2 Reduction in Power Plants. Proceedings of IGTI, ASME TURBO EXPO 2002, June 3-6, Amsterdam, The Netherlands.

Oliveira, AC (2007) A new look at the long-term performance of general solar thermal systems. Solar Energy 81: 1361-1368.

Sayigh, MAA, Khoshaim, BH (1981) Three and a half ton solar absorption air conditioner's performance in Riyadh, Saudi Arabi. Solar Cooling and Dehumidifying Pergamon Press, Oxford.

Thür, A, Furbo, S, Shah, LJ (2006) Energy savings for solar heating systems. Solar Energy 80: 1463-1474.

Van Hattem, D, Dato, PA (1981) Description and Performance of an Active Solar Cooling System Using an LiBr-H2 O absorption machine. Energy and Buildings 3: 169-196. Yeung, MR, Yuen, PK, Dunn, A, Cornish, LS (1992) Performance of a Solar Powered Air Conditioning System in Hong Kong. Solar Energy 48: 309-319.

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Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

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