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• Calibrated and rigorously validated model of silica gel-water adsorption chiller. • Screening of more than 40 adsorbents for application under data center conditions. • Review and evaluation of adsorption heat exchanger designs. • Cooling power of adsorption chiller can be increased by 59 % if MIL-100(Fe) is used. • (Partial) energy efficiency ratio (pumps and control, no fans) of > 20 is realistic. The electricity and water consumption of data centers is growing on a global scale. A shift towards liquid cooled racks in combination with thermally driven cooling can help to reduce the electricity and water demand associated with the necessary heat rejection. To quantify the potential of adsorptive heat transformation devices in reducing the electricity and water demand, the prediction of thermal efficiency, heat flow rates and energy efficiency ratio is required. To this end, a numerical model is newly developed using basic adsorption heat exchanger theory. This model can predict the necessary performance indicators with respect to temperatures and volume flow rates, heat exchanger design and adsorbent. The full performance map of a market-available adsorption chiller (71 points) and own measurements are used for calibration and rigorous validation of the model. An average deviation (experiment vs. calculation) of 8.3 % in terms of thermal efficiency and 7.2 % in terms of heat flow rates is achieved, indicating a very good agreement for a wide range of temperatures. At a moderate liquid cooled rack outlet temperature of 50 °C, a heat rejection temperature of 26 °C and a cold aisle inlet temperature of 18 °C the cooling power of the silica gel reference chiller of 5.3 kW can be increased by 59 % to 8.5 kW at a partial energy efficiency ratio (pumps and control, no fans) of > 20 by assuming MIL-100(Fe) as adsorbent on a flat-tube lamella heat exchanger. The model can be used in subsequent annual system simulations to quantify the savings in electrical power and water consumption, which strongly depend on the ambient conditions. [ABSTRACT FROM AUTHOR]

The transition to intermittent renewable energies will necessitate the integration of storage. An interesting technology is the Carnot battery (CB), a novel power-to-heat-to-power system, capable of harnessing waste energy streams. While initial studies have indicated that, under ideal conditions, CB can be competitive with conventional technologies such as chemical batteries, their economic viability in real-world applications remains uncertain. To fill this gap, this work explores the techno-economic potential of electric booster-assisted CB integrated within data centres. Motivation for this case study is the recovery of waste heat, leading to an improved electrical storage efficiency. To maximise the energy self-sufficiency and the internal rate of return, we have applied multi-criteria optimisation to the system design, under three different thermal integration scenarios and for two sets of climatic conditions, using a thermodynamic model and time series from a real data centre. Our analyses suggest that current projections for electricity prices and CB costs yield payback periods exceeding a decade, but that these could fall below ten years if the CB capital costs were halved. Furthermore, it turns out that the choice of optimum charging system (i.e. right balance between heat pump and electrical heater) is contingent on the heat source temperature and availability. For higher temperatures (e.g. 60 °C), heat pumps emerge as the financially most attractive option, thanks to their superior coefficient of performance, whereas for lower temperatures (< 25 °C), resistive heaters are preferable. Results also show that when the aim is to increase the energy self-sufficiency, there exist an efficiency/charging capacity trade-off, which causes a dilemma for the system design. On the one hand, heat pumps are vital to increase the efficiency of the CB, but on the other hand, as the amount of thermal energy available at its source is limited by the data centre operations, electrical boosters are indispensable to increase the charging capacity. To soften this dilemma and enhance the techno-economic performance of thermally integrated CB, future research should explore more efficient booster configurations, such as dual heat source heat pumps. • Thermal integration is not always beneficial due to limited waste heat availability. • The optimum booster configuration is contingent on the waste heat temperature. • Carnot batteries need better techno-economic performance to reach the market. • Higher efficiency, lower costs and new revenue streams are key to increase it. • Improved dual heat source heat pumps should be considered for efficiency gains. [ABSTRACT FROM AUTHOR]

• A waste heat driven cooling scheme for data center utilizing adsorption chiller is proposed. • A compact silica gel-water adsorption chiller is developed and experimentally studied under data center waste heat recovery scenario. • The adsorption chiller achieves the cooling power of 4.9 kW and the COP of 0.50 with the hot/cooling/chilled water inlet temperatures of 50 °C/30 °C/23 °C. • The compact adsorption chiller achieves a two-fold increase in volumetric cooling power compared with previous studies. In recent years, data centers have experienced rapid construction, leading to a significant surge in energy consumption, and cooling systems have emerged as prominent energy consumers of data centers. Among the cooling technologies, liquid cooling allows higher cooling circuit temperatures and provides potential for heat recovery. As a thermally driven cooling technology, adsorption refrigeration systems offer an alternative way to compression refrigeration systems by utilizing low-grade waste heat from liquid-cooled circuits to produce chilled water for air-cooled components. In this study, a compact silica gel-water adsorption chiller is developed for a small modular data center and experimentally investigated under extremely low driving temperatures. Under the typical summer conditions with the hot/cooling/chilled water inlet temperatures of 50 °C/30 °C/23 °C, the adsorption chiller achieves the cooling power of 4.9 kW and the COP of 0.50. When the cooling water inlet temperature changes from 32 °C to 24 °C, both the cooling power and COP show significant improvements, from 3.04 kW to 10.50 kW and from 0.44 to 0.66, respectively. Moreover, the increase of the hot water inlet temperature from 48 °C to 56 °C can enhance the cooling power to some extent, while the chilled water inlet temperature has little influence on the performance. The experimental results demonstrate the feasibility and performance of the developed adsorption chiller in data center waste heat driven cooling. Besides, potential adsorbents and possible optimization strategies are presented for performance improvement based on adsorption potential method. [ABSTRACT FROM AUTHOR]

• Proposing a low-energy consumption data center matching with multi-energy sources. • Recovering PEMFC's discharged heat to produce cooling capacity. • The exergy efficiency of the proposed system was increased by 9.78%. • The conventional and advanced exergy analysis was carried out. With the rapidly development of information service and artificial intelligence technology, the demand for data centers has dramatically increased, resulting in an increase of energy consumption and carbon emissions. This study proposed a power and cooling combined system with waste heat recovery, flexible cooling and hydrogen energy utilization used in data center to achieve the carbon peak and carbon neutralization. The integrated system mainly included the low temperature-proton exchange membrane fuel cell (LT-PEMFC) and the half-effect absorption refrigeration system (HE-ABS). The lower-grade heat discharged from LT-PEMFC was utilized by HE-ABS system to provide the cooling power. The performance modeling and advanced exergy analysis of the combined system were carried out. It was showed that the total exergy efficiency of the integrated system achieved 60.55 % and the exergy efficiency of LT-PEMFC subsystem was increased by 9.78 % due to the waste heat recovery of LT-PEMFC. In order to investigate the improvement potential and the interaction between subsystems, the advanced exergy analysis of the combined systems was conducted. The results showed that the avoidable exergy destruction of high-pressure absorber and low-pressure absorber of HE-ABS accounted for 80.9 % and 68.95 % of the total exergy destruction of components, respectively. The endogenous exergy destruction of the PEMFC was greater than its exogenic exergy destruction, which indicated that the exergy destruction of PEMFC was caused by its irreversibility. The parameter analysis showed, as the operating temperature of LT-PEMFC was increased, the exergy efficiency of PEMFC first increased and then decreased, and the maximum exergy efficiency of PEMFC achieved 70.44 % when the operating temperature of LT-PEMFC was 363 K. [ABSTRACT FROM AUTHOR]

• Performances of present water source heat pump (WSHP) unit were compared. • Three types of WSHP heating system using data center waste heat are proposed. • Thermal and energy characteristics of three proposed systems were studied. • Matching rule of data center waste heat, ending user and WSHP system is obtained. The number and scale of data centers (DCs) in China are constantly expanding with the advancement of networking and informatization. A large amount of waste heat is dissipated at its end. If this waste heat can be recovered, then achieving carbon neutrality in DCs can be effectively accelerated. At present, water source heat pump (WSHP) are widely used in air-cooled and liquid-cooled DCs of different sizes for waste heat recovery. This study analyzes the equipment type and heating capacity of different brands of WSHP units. Three WSHP heating systems are proposed according to the different locations of waste heat enhancement (SE, TDE, UE). The coupling and matching relationship between user-side heat load demand, DC waste heat load, and energy efficiency of WSHP units under different systems is also investigated. Moreover, the law of energy consumption and energy efficiency changes is analyzed. Thus, this study provides a reference for the DC waste heat recovery system design and equipment development. The results show that the coupling matching relationship between user-side heat load demand, DC waste heat load, and heating COP of WSHP units is Q. N / Q. S = C O P ′ / C O P ′ - 1 = φ , where φ ranges from 1.1962 to 1.3642. The heating COP of the SE system is the greatest when user-side heat load demand is between 0 and 120 kW. The heating COP of the TDE system is the highest when the user-side heat load demand is between 1750 and 70000 kW. Furthermore, the heating COP of the three WSHP heating system types is related to unit brand when user-side heat load demand is between 120 and 1750 kW. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dumbbell-shaped 3D flat plate pulsating heat pipe was proposed. • The performance augmentation of PHPs through capillarity gradient was discussed. • The junction temperature of the heating source could be reduced by 42.49 °C. • It can manage an input power of 300 W with junction temperature below 85 °C. With the development of the data center industry and the increasing power density of servers, it is crucial to remove waste heat from small-area heat sources to ensure the safe and efficient operation of data processing chips. To complement existing studies, in this paper, a novel three-dimensional flat plate aluminum pulsating heat pipe (3D-FPPHP) with four different channel structures for radial heat dissipation of high-power server chips was proposed. The results showed that under the favorable influence of the additional capillarity force provided by the variable diameter channels, the FPPHP filled with acetone can start up easily and has good robustness during variable power operation. When the input power was 150 W, the junction temperature of the heating source could be reduced by 42.49 °C (48.67%) compared to an identical aluminum plate. In addition, a heat sink module based on the proposed 3D-FPPHP with optimal charging ratio was tested in a 1U server chassis. The results showed that it can manage an input power of 300 W (corresponding to a heat flux of 41.15 W/cm2) and achieve a total thermal resistance of 0.2053 °C/W under the premise of ensuring a safe junction temperature of chips below 85 °C. [ABSTRACT FROM AUTHOR]

In the past two decades, data centers have significantly grown in size and number around the globe, leading to substantial energy and water stress wherever they operate. Thermal management typically represents half of the total energy consumption in traditional data centers. This work studies the energy and water savings that air-side free-cooling yields under diverse weather conditions. We modeled a free-cooling system and a conventional data center using MATLAB. The hourly weather data was obtained from a publicly available online repository for the Chilean territory. Using air-side free-cooling for data center thermal management is feasible in various weather conditions. Locations with colder temperatures (< 20 °C) and higher humidity (> 60%) are more favorable as they require minimal use of the chiller and/or humidifier. These conditions are present in BSk'(s) Cold Semi-arid climate with dry summer and oceanic influence, as well as Csb' Mediterranean climate (warm summer) with oceanic influence. However, locations with drier air (< 50%) and warmer temperatures (> 20 °C), such as those found in ET(w) Tundra climate with dry winter, BWk(w) Cold Desert climate with dry winter, or BSk(s) Cold Semi-arid climate with dry summer, are less suitable for air free cooling. Even under suboptimal energy and water savings, the air-side economizer still performed considerably better than a conventional data center cooling method (using CRAH units). • Free-cooling and conventional data centers are modeled using hourly weather data. • Air-side free-cooling economizer may save energy and water depending on the weather. • BSk'(s) and Csb' climates show significant energy and water savings. • Negligible usage of chiller and humidifier in some weather conditions. [ABSTRACT FROM AUTHOR]

• Combined cooling, heating and power (CCHP) system integration for data centers are investigated in terms of reliability, availability and life-cycle cost (LCC) analysis. • The proposed overall system considers both electricity and cooling supplies of data center without affecting data center Tier requirements. • The true influence of the CCHP system is demonstrated by evaluating a data center that is already highly reliable and available with 2 N redundancy. • The importance of reliability and life-cycle cost analysis for the alternative energy systems has been highlighted besides the commonly used availability performance criteria in data centers. • The CCHP integration increased the reliability and availability performance of a grid-fed data center significantly. The utilization of digital technology is increasing rapidly and it is causing a growth in the number of data centers around the world. Data centers provide essential services, making them known as mission-critical. Like other mission-critical facilities, data centers often use reliability and availability analysis to evaluate the level of safety of their operations. Reliable electricity and cooling supplies are vital for the data center's operation, and almost all data centers rely on the power grid to feed their electrical and cooling systems. However, the power grid is considered an unreliable source, and power grid fragility is a raising concern among data center operators. An alternative to the power grid is a sustainable combined cooling, heating, and power (CCHP) system, which can supply continuous electricity and cooling to a data center while providing local energy generation, energy cost saving, and emission benefits. To understand the impact of a CCHP integration on the reliability and availability of a grid-fed data center, an up-to-date electrical topology design and reliability block diagram models were created that take into account both electricity and cooling supplies. The results showed that the overall system reliability of a grid-fed data center increased from 49.23% to 74.62% with a CCHP integration. In terms of availability, a grid-fed data center with 2N redundant topology achieved the industry-accepted high availability level of 0.99999, also known as 5-nines. Moreover, the use of CCHP at the grid-fed data center increased the availability from 5-nines to 7-nines for the overall system. Thus, CCHP integration to a grid-fed data center provided higher reliability and availability for the overall system for even 2N redundant topology data centers. Moreover, based on the life-cycle cost (LCC) analysis, integrating CCHP systems into data centers has a promising outcome. However, when conducting an LCC analysis, we recommend considering the realistic cost of downtime along with the reliability-related exposure to properly assess the viability of alternative energy systems by data center investors and operators. [ABSTRACT FROM AUTHOR]

• The Stanford Energy System Innovations plan is adapted to a university in Valencia. • Waste heat recovery from a large data centre is used to heat campus buildings. • A polyvalent heat pump that can simultaneously provide cooling and heating is used. • Thermal energy and emission savings of more than 64% in three campus buildings. • The findings help to promote similar studies in Mediterranean universities. In this research work, the Stanford Energy System Innovations action plan is adapted to the decarbonization of the Universitat Politècnica de València, of the Mediterranean coast of Spain. Special focus is dedicated to waste heat recovery from a data centre located on campus with an almost constant cooling demand throughout the year, amounting to a yearly 1,661,020 kWh. To recover the waste heat generated by the data centre, a method for assessing thermal performance of the system is presented, which is implemented by selecting a 300 kW polyvalent heat pump (capable of easily switching from water-to-water to air-to-water working modes). It can simultaneously provide cooling and heating to a set of strategically identified buildings on the campus: the university data centre and three buildings located nearby that currently use the university's central natural gas boilers for heating. A thermal storage system is designed to balance the cooling and heating needs. The results lead to potential thermal energy savings of more than 254,106 kWh/year, and a consequent reduction in CO 2 emissions of at least 64,035 kg/year, supporting the decarbonization of the Vera campus. The outcomes of the study can help to design similar research projects applied to large data centres in Mediterranean cities. [ABSTRACT FROM AUTHOR]

• Six combined cooling and power systems with multi-mode operation are proposed. • The proposed systems can realize diversified power and cooling supply. • Evaluated by parametric study and multi-objective optimization. • The ORC/ARC is considered as the optimal system in any of the operation mode. • The energy efficiency at the optima is 58.13% and unit cost of product is 4.25 $/GJ. Current solutions for waste heat recovery from data centers are mainly district heating and refrigeration. However, intermittent demand for space heating and cooling resulted from seasonal or spatial variations makes inefficient utilization of waste heat. To better harvest the low-grade thermal energy in data centers, combined cooling and power systems are proposed, with the capability of adjusting the energy output to meet diverse energy demands hourly and seasonally. In total, six cogeneration systems with different configurations are investigated, with the power cycles being either organic Rankine cycle or Kalina cycle, and the refrigeration cycles being vapor compression refrigeration cycle, ejector expansion refrigeration cycle or absorption refrigeration cycle. Depending on the energy demands of data centers, each system has three operation modes: combined cooling and power, power alone and cooling alone. The performance is evaluated in terms of both the thermodynamic and economic performance by parametric study and multi-objective optimization. Results show that the organic Rankine cycle/absorption refrigeration cycle hybrid system has the best thermal-economic performance in all three modes. According to the comprehensive evaluation of the TOPSIS method and the entropy weight method, the energy efficiency at the optima is 58.13%, and the unit cost of product is 4.25 $/GJ, with the net power output of 4.25 kW and the cooling capacity of 150 kW. [ABSTRACT FROM AUTHOR]

• A PEMFC-driven CCP system with heat pipe for data center applications is proposed. • New operation strategies for power and cooling supplies in a CCP system are proposed. • Performances of two PEMFC-driven CCP systems with multiple cooling are compared. • Effect of heat pipe on the power and cooling supplies in the CCP system was studied. With the dramatic development of data centers, the energy management system in data center applications has become significantly important in recent years. A proton exchange membrane fuel cell (PEMFC)-driven combined cooling and power (CCP) system with multiple cooling devices was proposed in this paper to fully utilize a natural cold source. Another CCP system without natural cold source utilization was also proposed for comparison. Power and cooling were supplied to these systems with new operational strategies. Based on the proposed model, the operational performance of the two CCP systems was analyzed for a sample data center. The seasonal and annual power supplied, cooling supplies, matching degrees, energy consumption for removing cooling loads, and system efficiencies in the two proposed CCP systems are discussed and analyzed in detail. Results indicate that by using the designed operational strategies, the power and cooling supplies almost matched perfectly with the requirements of the sample data center. The annual energy efficiencies can reach 86.53% and 85.02% for the two proposed CCP systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel solution to facilitate adopting liquid cooling technologies is introduced. • Cooling capacity and data center power usage effectiveness are used to evaluate the heat exchanger performance. • The operating conditions effect on the heat exchanger performance is investigated. • Energy efficient hybrid cooled data center operation is investigated. With the remarkable surge in IT power densities and energy consumption, the data center industry is starting to adopt energy and thermally-efficient single-phase cooling technologies. For many legacy data centers worldwide, the lack of a primary chilled water source is a substantial barrier to adopting single-phase technologies. In this study, the necessity of having a facility chilled water source for deploying liquid cooling solutions is eliminated by introducing a solution that does not require bringing in any modification of the data center layout. This simple solution proposes integrating liquid to air heat exchangers with the floor tiles to eject heat from the liquid-cooled IT equipment into the room air. An experimentally validated CFD modeling approach is used to investigate the performance of these heat exchangers. Results show that by installing two heat exchangers in different cold aisles, a significant amount of cooling load is handled at the design point conditions. When they are tested under different operational conditions, the cooling capacity of these heat exchangers is shown to be sensitive to the supply air temperature. To overcome the operational constraints stemming from the supply air temperature, an alternative configuration with just one heat exchanger installed in the hot aisle is considered and discussed. Results indicate that the second configuration shows superior performance to the first one in terms of sensitivity to supply air temperature and cooling capacity. Lastly, with this configuration, the data center utilizes energy extremely efficiently and achieves a power usage effectiveness of 1.06. [ABSTRACT FROM AUTHOR]

• Use CO 2 heat pump to recover waste heat from data center for district heating. • Optimal system design schemes and benefits at various scenarios are analyzed. • Use cooling water waste heat from IT room is preferred than that from chillers. • Energy cost can decrease by 23.0%–75.0% compared with common heating methods. • Energy efficiency and financial performance of data center are also improved. Recovering waste heat from data center (DC) for district heating by CO 2 transcritical heat pumps can effectively improve the performance of DC and reduce CO 2 emission of district heating. However, the optimal design schemes, financial and environmental benefits, and market competitiveness of waste heat heating system are still unclear for different application scenarios. To realize the optimal system design and evaluate the benefits at different application scenarios, this work analyzed and compared the comprehensive performance of four system design schemes, considering two waste heat recovery locations and two cycle types. The maximum coefficient of performance (COP) was set as the optimization goal. Influences of electricity and heat prices on the optimal scheme and thermo-economic performance of waste heat heating system were analyzed. The direct electric-heating, coal-heating, gas-heating, air source heat pump, and ground source heat pump were selected as the comparative heating methods to evaluate the market competitiveness of waste heat heating system. Results show that using waste heat of cooling water from IT room achieves a better thermo-economic performance than that from chillers, which increases maximum COP by 18.2%–28.9% and reduces system investment cost by 4.2%–10.2%. The COP of IHE cycle (e.g., add an internal heat exchanger in the simple cycle) is larger, whereas the simple cycle has a lower investment cost. The cycle type with the shortest dynamic payback period depends on actual electricity and heat prices. The financial and environmental benefits of waste heat heating system are very attractive since it can reduce energy cost by 23.0%–75.0% compared with common heating methods and reduce CO 2 emission by 12,880 tons annually compared with gas-heating. Furthermore, the energy efficiency of DC will be improved by waste heat reuse, and the annual energy reuse effectiveness (ERE) can decrease from 1.296 to 0.902 at the annual heating time of 121 days. [ABSTRACT FROM AUTHOR]

• A silica gel-H 2 O adsorption chiller recovers low-temperature data center waste heat • Different aspects of energy, economic, and environmental feasibility is provided • Parametric sensitivity analysis of the heat recovery system is conducted • There is 22.5% energy savings efficiency with as low as 279 days of payback period • Certain ESE improvement scenarios degrade computing performance per watt by up to 6% Computing load of data centers and high-performance clusters have increased significantly over the past decade, resulting in higher energy consumption and a larger carbon footprint. We provide a method to utilize the waste heat from a data center room that contains both air- and water-cooled racks. Heat dissipated by the water-cooled racks drives a silica gel-H 2 O adsorption chiller, which produces chilled water required for in-row cooling units installed in the air-cooled racks. Hence, the cooling load of the existing vapor-compression chiller is either partially or fully eliminated, offering significant energy savings. Thermodynamic, economic, and environmental benefits of the proposed strategy are compared against a baseline infrastructure without waste heat utilization. Parametric sensitivity analyses reveal that the load sharing factor, inlet temperature of water-cooled racks, chilled water setpoint, airflow of the in-row cooling units, and the re-cooled water temperature all influence the energy savings efficiency, annual variable costs, CO 2 emission reduction, and cost payback period. In this manner, energy savings efficiency is enhanced by 22.5% and annual CO 2 emissions reduced by 104 tons. The cost payback periods with 30 and 90 kW adsorption chiller retrofits are as low as 379 and 285 days. Raising the water-cooled rack inlet temperature from 40 °C to 65 °C enhances the energy savings efficiency by as much as 16% but that also degrades computing performance per watt by 6%. [ABSTRACT FROM AUTHOR]

• A data center acts as a prosumer using a carbon dioxide ground source heat pump. • Heat is stored during the non-heating period and retrieved in the heating period. • Prosumer data center demonstrated better energy, exergy, and economic performance. With increasing reliance on information technology by modern society, the scale and energy consumption of data centers (DCs) are rising rapidly. Approximately 40% of the energy consumed by DCs is associated with refrigeration systems used to maintain optimal operation temperatures. Such systems produce large amounts of waste heat; therefore, the utilization of the waste heat is essential for the optimization of the energy efficiency of DCs, especially with regard to DC prosumers (producers and consumers). However, the low temperature of the waste heat and variation in load demand are two factors limiting the exploitation of waste heat from DCs. In this study, a prosumer DC energy system based on a ground source heat pump (GSHP) is proposed for the recycling of waste heat from DCs for the heating of surrounding buildings. The heat generated in the non-heating period is stored in the soil and made available for building heating using a carbon dioxide (CO 2) direct-expansion GSHP. Furthermore, the cooling power consumption, total power consumption, exergy efficiency, and net profit of the prosumer DC waste heat energy recovery system are evaluated. Compared to conventional cooling systems that use air source heat pumps (ASHPs) for building heating, the energy, exergy, and economic (3E) performance of the prosumer DC have the following advantages: 1) the prosumer DC waste heat energy recovery system yields a heat-power ratio of 5.70, with a total power consumption approximately half (52.86%) that of the conventional system; 2) the matching thermodynamic properties are greatly improved; specifically, the exergy efficiency of the prosumer DC waste heat energy recovery system is 3.87 fold that of the conventional system; 3) better economic revenue of the prosumer DC waste heat energy recovery system generates more economic revenue, with an annual net profit approximately 190.34% of that generated by the conventional system. In general, the prosumer system facilitates flexible and effective utilization of the low-temperature waste heat, by coupling the upstream power supplier and downstream thermal users through a GSHP. [ABSTRACT FROM AUTHOR]

Since the energy and environment issues, adsorption refrigeration technology has raised the great attention and interest by worldwide researchers and scholars, because it can efficiently use low-grade heat and its refrigerants are natural. Among the numerous working pairs of adsorption refrigeration, silica gel-water is most suitable for massive applications in solar and waste heat field, as its developed technology and low driving temperature. In this paper, application analysis of adsorption refrigeration system for solar and data center waste heat utilization and economic evaluation, based on investment of main components, operation cost and payback period, is done. For the study of solar cooling application, a validated mathematical model of silica gel-water adsorption chiller is used. For very low temperature waste heat (up to 60 °C) recovery of data center, feasibility of silica gel-water adsorption chiller has been analyzed by previous experimental study. Through the investigation, payback period of solar cooling application using adsorption chiller is too long to get any economic benefit, based on the real weather conditions of Shanghai. Data center waste heat recovery by adsorption chiller has very short payback period and this application has greater economic potential and brighter prospect in the future than solar cooling application. [ABSTRACT FROM AUTHOR]