Realistic Simulation Tool for practical Analysis of Solar Cooling Thermal Systems driven by Linear Fresnel Collectors

The objectives of this study were to develop a realistic simulation tool to analyze solar thermal cooling systems driven by Fresnel collectors and carry out a case study in which the performance of a solar cooling system of 190 kW located in Riyadh is simulated to demonstrate the functionality and potentiality of the developed tool. This tool is based on an integrated mathematical model that considers the ambient conditions, the thermal loads of the building, the pre-sizing data of each of the components of the system and the simultaneous interaction among them, to conduct a realistic, simple, and precise analysis. A demonstrative simulation example was performed. During the month of July, with a solar opening area of 704 m2 and a tank of 35200 L, a total amount of 47,5 MWh of cooling energy was obtained, with a reduced contribution of the auxiliary system (5,6 MWh) and a minimum number of solar collector system deactivation hours (0,7 %). The daily COP of the absorption machine remained above 0,69. The obtained results from the case study with the simulation tool allowed to verify its functionality, capabilities and correct operation to carry out hourly and parametric studies of this type of systems.

Techno feasibility analysis of a concentrating solar thermal cooling systems at a university complex

Concentrating solar thermal (CST) energy applications are growing worldwide, especially in combined cooling, heat, and power processes. Building upon the analysis of a building’s thermal comfort, and software simulations for CST, the current study evaluates a solar conditioning system integrated with absorption systems. The cooling system is equipped with single-, double- and triple-effect configurations cycle, production parameters, and thermal storage. The required fraction of auxiliary energy for the system operation is estimated. The results indicate that the double effect system is the best configuration for the adopted location in Brazil. The system’s annual auxiliary energy demand is, approximately, 20%. Triple-effect systems require less energy at higher temperatures due to local direct radiation, which then leads to an intermittent operation and greater auxiliary energy demands. The methodology applied in this work could be adopted in different locations, with an emphasis on the possibility of testing smaller scale systems in small buildings.

Evaluation of Coupling PV and Air Conditioning vs. Solar Cooling Systems—Case Study from Jordan

When they were first conceived, solar cooling systems were designed to be cost-effective and environmentally safe alternatives for the majority of the developing nations that are characterised by their hot climates in contrast with the traditional air conditioning systems powered by electricity that is produced from fossil fuel resources. Nevertheless, developments in photovoltaic (PV) and air-conditioning technologies have impacted on the prospects of solar cooling systems. This study examined two different options: a coupled PV and air conditioner system and a solar cooling system (absorption chillers where thermal energy is provided by solar collectors) for a specific developing country located in the Eastern Mediterranean region whose climate is hot and dry (Jordan). The cooling system comprised a pair of cooled multistage compression, both of which were 700 kW, while the PV system’s size was 2.1 MWp, the utility grid connection was a 0.4 kV 50 Hz net meter (2 m) and it was anticipated that 3300 MWh/year would be generated. The solar cooling system operated at a maximum coefficient of performance (COP) of 0.79 and had an actual recorded COP of 0.32 on the site; when the electricity tariff of $0.1/kWh was considered, the respective levelised cost of energy (LCOE) values were $0.9/kWh and $2.35/kWh respectively. The findings indicate that the initial costs for the solar thermal cooling system and the PV system were approximately $3.150M and $3M, respectively. The current value of future cash payments when discounts of 6% per year were applied to the payments for the combination of PV and air conditioning was about $9,745,000, whereas the solar thermal cooling system will not reach the breakeven point at negative $1,730,000. It is clear the absorption chiller did not display economic feasibility, whereas the value for the coupled PV and air-conditioning systems was under $0.05/kWh. In addition to the extensive maintenance needs, the reduced COP and the practicality and feasibility of the solar thermal cooling systems mean these kinds of technologies are under significant pressure to remain competitive when faced with the development of new air conditioning and PV technologies.

Potential Study of Solar Thermal Cooling in Sub-Mediterranean Climate

Air conditioning is becoming increasingly important in the energy supply of buildings worldwide. There has been a dramatic increase in energy requirements for cooling buildings in the Middle East and North Africa (MENA) region. This is before taking the effects of climate change into account, which will also entail a sharp increase in cooling requirements. This paper presents the potential of using a solar thermal absorption cooling system in Sub-Mediterranean Climate. Four sites in Jordan are now equipped with water-lithium bromide (H₂O-LiBr) absorption chillers with a total nominal capacity of 530 kW. The focus of the paper was on the pilot system at the German Jordanian University (GJU) campus with a cooling capacity of 160 kW. The system was designed and integrated in order to support two existing conventional compression chillers with a nominal cooling capacity of 700 kW. The system was economically evaluated based on the observed cooling capacity results with a Coefficient of Performance (COP) equals 0.32, and compared with the values observed for a COP of 0.79 which is claimed by the manufacturer. Several techniques were implemented to evaluate the overall economic viability in-depth such as present worth value, internal rate of return, payback period, and levelized cost of electricity. The aforementioned economic studies showed that the absorption cooling system is deemed not feasible for the observed COP of 0.32 over a lifespan of 25 years. The net present value was equal to −137,684 JD and a payback period of 44 years which exceeds the expected lifespan of the project. Even for an optimal operation of COP = 0.79, the discounted payback period was equal to 23 years and the Levelized Cost of Electricity (LCOE) was equal to 0.65 JD/kWh. The survey shows that there are several weaknesses for applying solar thermal cooling in developing countries such as the high cost of these systems and, more significantly, the lack of experience for such systems.

Development and Implementation of Solar Assisted Desiccant Cooling Technology in Developing Countries: A Case of Saudi Arabia

This paper presents a comprehensive overview of the potential and feasibility of using solar thermal cooling systems in the Kingdom of Saudi Arabia (KSA). The performance of a desiccant cooling system has been determined based on climatic data of 32 cities spread all over the territory of the country. The investigation has been carried out keeping in view the high energy consumption for cooling applications in the country. The analysis has been done using the overall performance of the system, sensible energy ratio, and cooling and regeneration loads. The main objective of this study is to encourage the implementation of solar thermal cooling systems in the country for the development of sustainable buildings. The economic analysis shows that thermal cooling technology can reduce the cost of cooling units, remarkably. Furthermore, the utilization of the proposed system will decrease the dependence on primary energy resources. The saving factor of the proposed system with 1 ton capacity in comparison to the conventional vapor compression unit is found to be 34.6%. The present study also recommends that the government subsidies and incentives can further improve the development and utilization of solar air conditioning technology in developing countries.

Energy Analysis for the Solar Thermal Cooling System in Universitas Indonesia

The objective of this study is to analyze all the energy used in the solar cooling system in Universitas Indonesia. This system uses three energies at the same time, namely, solar, gas and electricity energies, which are used to provide a required cooling capacity from the mechanical research center (MRC) building in Universitas Indonesia. The single–double-effect absorption chiller is the main component of the solar thermal cooling system to provide the chilled water that is circulated between the system and MRC building. In this system, heat from solar energy is absorbed by the evacuated tube solar collector and then transferred to the hot water that is used to generate vapor together with the gas at the absorption machine. On the other hand, electricity is mostly consumed by the pumps to circulate the hot, cooling and chilled water, also the working fluids inside the absorption machine. Finally, all the energies used to create a thermal comfort zone in the MRC building based on the Indonesia weathers are reported in this paper.

Potential of integrating power generation with solar thermal cooling to improve the energy efficiency in a university campus in Saudi Arabia

Along with the rapid ongoing developments and expansions of the King Abdulaziz University campus, it is sensible to rethink the way electrical and cooling energy is generated and to explore methods to increase energy efficiency in the academic facilities. A conceptual energy master plan for the entire campus has been developed to achieve feasible results which require a substantial reduction in energy demand in the first place. It combines strategies at the master plan level and the micro level (case study: a single building). Establishing a correlating link between the macro and the micro level is imperative to improve the efficiency of the total system. Therefore, possibilities for centralized and decentralized (building related) energy generation have also been investigated to improve the efficiency of the total system. After outlining the general strategies for renewable energy generation on the master plan level in the university campus of King Abdulaziz University, this study explores the potential of increasing the energy efficiency of an individual building. Key energy saving actions have been simulated using IDA-ICE to assess the possibility to release the load on the shared existing and future energy infrastructure. Besides roof-integrated solar panels, the capacity of carport incorporated energy generation has also been analyzed. The results of the study indicate possible substantial savings on the current consumption of non-renewable energy resources and a combined generation of electrical energy and solar thermal cooling can lead to high coverage fraction.