Compressed Air Energy Storage Technology Research Articles

Plastic zone and surrounding strain analysis in a lined cavern for compressed air energy storage subjected to cyclic high internal gas pressure and temperature

In the context of compressed air energy storage (CAES) technology, the strategic excavation of hard rock caverns is pivotal for overcoming geological challenges and advancing CAES deployment. This study adopts a circular profile for the cavern and investigates the impact of variables such as cavern diameter and depth. Considering the influence of cyclic internal gas pressure, temperature fluctuations, and potential leakage on the cavern, a thermo-hydro-mechanical coupled numerical model is developed using Comsol software. This model, grounded in classic elastoplastic constitutive relations, aligns with the conditions of a proposed project. It facilitates the computation of the plastic zone and surrounding strain for both the cavern lining and adjacent rock, post-excavation and throughout a typical ‘charging-storage-discharging-storage’ operational cycle. Through detailed analysis, the study delineates the variations and characteristics of the plastic zone and surrounding strain, thereby providing a solid foundation for a comprehensive examination of cavern stability, and the design of linings and sealing mechanisms.

Performance analysis of a compressed air energy storage incorporated with a biomass power generation system

Compressed air energy storage technology is recognized as a promising method to consume renewable energy on a large scale and establish the safe and stable operation of the power grid. To improve the energy efficiency and economic performance of the compressed air energy storage system, this study proposes a design for integrating a compressed air energy storage system with a biomass power generation system. In the energy storage process, the feedwater from the biomass power generation system is used to cool the compressed air in the compressed air energy storage system. In the energy release process, the flue gas from the biomass power generation system is used to heat the compressed air. Besides, the compressed air from the compressed air energy storage system first works in the expander and then goes to the biomass power generation system for combustion. Based on the system simulation, the proposed system is assessed from the energy, exergy, economy, and environment perspectives. The results show that the round-trip efficiency and the energy storage density of the compressed air energy storage subsystem are 84.90 % and 15.91 MJ/m3, respectively. The exergy efficiency of the compressed air energy storage subsystem is 80.46 %, with the highest exergy loss in the throttle valves. The total investment of the compressed air energy storage subsystem is 256.45 k$, and the dynamic payback period and the net present value are 4.20 years and 340.48 k$. Besides, the proposed system’s CO2 emission is 258 kg/GWh. This study provides a new option for enhancing the performance of compressed air energy storage through the system integration.

Status and Development Perspectives of the Compressed Air Energy Storage (CAES) Technologies—A Literature Review

The potential energy of compressed air represents a multi-application source of power. Historically employed to drive certain manufacturing or transportation systems, it became a source of vehicle propulsion in the late 19th century. During the second half of the 20th century, significant efforts were directed towards harnessing pressurized air for the storage of electrical energy. Today’s systems, which are based on storing the air at a high pressure, are usually recognized as compressed air energy storage (CAES) installations. This paper aims to provide an overview of different technologies that take advantage of the energy accumulated in the compressed air. Particular attention is paid to the CAES installations that are working as electrical energy storage systems (EESs). These systems, developed originally as large capacity (>100 MWe) and fuel-based installations, may soon become fully scalable, highly efficient, and fuel-free electrical energy storage systems. To present this opportunity, a thorough review encompassing previous and up-to-date advancements in their development was carried out. In particular, CAES concepts, such as diabatic (D-CAES), adiabatic (A-CAES), and isothermal (I-CAES), are described in detail. This review also provides the detailed characteristics of the crucial elements of these configurations, including compressors, expanders, air storage chambers, and thermal storage tanks. Knowledge of these components and their role allows us to understand the main challenges behind the further development of the mentioned CAES setups. Apart from the CAES systems that are designed as EES systems, this paper describes other prospective technologies that utilize the energy of pressurized air. Accordingly, compressed air cars and their key elements are explained in detail. Moreover, the technology renowned as wave-driven compressed air energy storage (W-CAES) is described as well, indicating that the utilization of pressurized air represents a viable option for converting ocean energy into electrical power.

Development and technology status of energy storage in depleted gas reservoirs

Utilizing energy storage in depleted oil and gas reservoirs can improve productivity while reducing power costs and is one of the best ways to achieve synergistic development of "Carbon Peak–Carbon Neutral" and "Underground Resource Utilization". Starting from the development of Compressed Air Energy Storage (CAES) technology, the site selection of CAES in depleted gas and oil reservoirs, the evolution mechanism of reservoir dynamic sealing, and the high-flow CAES and injection technology are summarized. It focuses on analyzing the characteristics, key equipment, reservoir construction, application scenarios and cost analysis of CAES projects, and sorting out the technical key points and existing difficulties. The development trend of CAES technology is proposed, and the future development path is scrutinized to provide reference for the research of CAES projects in depleted oil and gas reservoirs.Graphical abstract

Thermodynamic and techno-economic evaluation of a CAES based cogeneration system integrated with high-temperature thermal energy storage and ammonia absorption refrigeration

The development of compressed air energy storage (CAES) technology can ensure the safe and stable operation of the power system, promote the consumption of renewable energy and reduce carbon emissions. In order to improve the comprehensive performance of the CAES system and meet the diversified demand of energy, a cooling, heating and power cogeneration system based on compressed air energy storage with high temperature thermal energy storage and ammonia absorption refrigeration are developed in this study. The compression heat of the energy storage process and the exhaust waste heat of the energy release process are fully utilized in this system. Thermodynamic analysis, techno-economic evaluation and parametric analysis are conducted. The thermodynamic analysis results show that the proposed system achieve an ENE of 81.51 %, an EXE of 53.51% and an ESD of 7.08 kWh/m3 under the design condition. The economic analysis results indicate that the NPV, IRR and LCOE for a system life of 25 years are 489497 $, 32.1 % and 0.0953 $/kWh, with a DPP of 3.91 years. Sensitivity analysis results conclude that the outlet temperature of HTTES, and the maximum and minimum operating pressures are the key parameters affecting the system performance.

Maximizing Efficiency in Compressed Air Energy Storage: Insights from Thermal Energy Integration and Optimization

Motivated by the suboptimal performances observed in existing compressed air energy storage (CAES) systems, this work focuses on the efficiency optimization of CAES through thermal energy storage (TES) integration. The research explores the dependence of CAES performance on power plant layout, charging time, discharging time, available power, and cavern volume. Hence, a range of solutions are examined, encompassing both solid and liquid TES options, alongside the potential utilization of external air heaters. Inefficiencies in solid TES due to significant retention of thermal power within the medium after complete discharge are identified and mitigated through optimization strategies. In addition, solutions to prevent ice formation at the low-pressure expander phase are suggested to avoid icing issues in CAES layouts with liquid TES. Through this comprehensive investigation, the study provides valuable insights into enhancing the efficiency and sustainability of CAES systems. By constructing a volume–power–time conversion table, the research contributes to the advancement of CAES technology, facilitating more efficient energy storage and utilization, thereby addressing critical challenges in the field of energy storage.

WITHDRAWN: A Critical Review on Compressed Air Energy Storage in Underground Geological Media: Advances and Future Outlook

Renewable energy sources such as wind, tidal, and solar power have emerged as the major clean energy sources globally to reduce or replace fossil fuel use to mitigate global climate change. Nevertheless, renewable sources exhibit sporadic and unstable characteristics, leading to significant challenges in grid integration and power fluctuations. Consequently, these difficulties might disrupt the overall stability of the grid. In instances of this nature, the significance of energy storage technologies becomes paramount, prompting researchers to redirect their focus towards identifying effective methods of energy storage that may optimize consumption to its fullest extent. Compressed air energy storage (CAES) is widely regarded as a vital technical solution for addressing the disparities between the generation of clean power and the corresponding demand for electricity because other storage technologies have high costs and limited feasibility in the context of renewable sources. This paper reviewed critically the CAES recent progress focused on developments of experimental works, modelling and simulations, and field applications of the CAES technology. It has been revealed that CAES in underground geological media (UGM) such as caverns and aquifers have great potential to store these energy sources and release them during high energy demand period. Despite the continuous research in CAES in UGM, particularly experiments, modelling and simulations, there are recently few new reported Adiabatic CAES in China and Canada full field applications apart from Huntorf and McIntosh. Further, it was found that super compressibility carbon dioxide (CO2) can be used as cushion gas during CAES because it increases the discharging pressure than charging pressure which led to production rate to increase four times than injection rate. Also, recommended policies in this paper may encourage the development and deployment of CAES technology as part of a sustainable and reliable energy system. Furthermore, identified challenges in this paper must be addressed and centred on enhancing CAES technology, monitoring systems, and materials to improve the technology's efficiency, cost-effectiveness, and environmental sustainability. The identified research gaps in this paper will pave the way for stake holders, academia, and researchers to conduct more research in CAES in underground geological media towards full field application on a global scale as a clean source of energy to combat global climatic change in future and supply energy during high demand period.

Techno-Economic Analysis of a Thermally Integrated Solid Oxide Fuel Cell and Compressed Air Energy Storage Hybrid System

Natural-gas-fueled solid oxide fuel cell (SOFC) systems have the potential for high-efficiency conversion of carbon to power due to the underlying electrochemical conversion process while readily facilitating carbon capture through the separation of the fuel and oxidant sources. Compressed air energy storage (CAES) technology can potentially store significant quantities of energy for later use with a high round-trip efficiency and lower cost when compared with state-of-the-art battery technology. The base load generation capability of SOFC can be coupled with CAES technology to provide a potentially flexible, low-carbon solution to meet the fluctuating electricity demands imposed by the increasing share of intermittent variable renewable energy (VRE) production. SOFC and CAES can be hybridized through thermal integration to maximize power output during periods of high electrical demand and then store power when either demand is low or renewable generation reduces power prices. The techno-economics of a low-carbon hybrid SOFC and CAES system was developed and investigated in the present study. The proposed hybrid system was found to be cost-competitive with other power-generating base-load facilities when power availability was considered. The hybrid system shows increased resilience to changes in a high VRE grid market scenario.

A thermo-hydro-mechanical damage model for lined rock cavern for compressed air energy storage

Large-scale compressed air energy storage (CAES) technology is regarded as an effective way to alleviate the instability of electricity generated from renewable sources such as wind and solar power, which involves the expensive construction of underground caverns to store highly pressurized and high-temperature compressed air. This study documents mechanical behavior and gas permeability of granite under temperature-pressure synchronous cyclic loading, and the response of the surrounding rock to Thermo-Hydro-Mechanical-Damage (THMD) evolution. Firstly, physical experiments were conducted to examine mechanical property and gas permeability evolutions of granite due to temperature-pressure synchronous cyclic loading. Based on these experiments, equations describing the damage evolution of granite were deduced. Subsequently, using these equations in combination with a thermo-hydro-mechanical coupled model of porous media with two-phase fluid flow, a sophisticated computational routine for the thermo-hydro-mechanical-damage analysis of underground gas storage caverns was developed. Lastly, numerical simulations were conducted to study heat transfer, two-phase seepage, and mechanical response of a CAES cavern under operating conditions. Under low to medium pressure and high-temperature synchronous cyclic loading, granite exhibited a significant variation in elastic modulus and compressive strength. Also, its permeability showed a substantial increase due to damage evolution. After two months of operation, prominent heat transfer was observed in the surrounding rock, particularly in the region extending to approximately 10 m from the inner surface of the cavern, exceeding the range of gas leakage diffusion within the cavern. The plastic zone of surrounding rock is distributed above the cavern's roof and below its bottom. Moreover, areas with higher damage are concentrated in the surrounding rock near the cavern's side walls. These findings contributed to our understanding of the behavior of granite in the context of CAES technology and provided valuable insights for the design and operation of gas storage caverns. The development of the THMD model offered a valuable tool for investigating stress and deformation characteristics of the lining and surrounding rock in CAES plants.

Numerical study of heterogeneous condensation in the de Laval nozzle to guide the compressor performance optimization in a compressed air energy storage system

Compressed air energy storage technology (CAES) has an enormous possibilities in terms of energy conversation, environmental protection, and economic benefits. Air compressor, as a core component, is of great significance for the CAES system efficiency. The impact of the non-equilibrium condensation of steam contained in the air on the blade erosion and thermal efficiency drop in the compressor is not to be missed. The compressor flow characteristics in blade-to-blade channels can be reproduced by the flow in the Laval nozzle, which can verify the accuracy of the condensation model based on similar flow characteristics and subcooling conditions in the non-equilibrium condensation flow. Firstly, the homogeneous condensation flow is numerically investigated by different condensation models, and the Blend model is used to investigate the heterogeneous condensation because of its higher accuracy. Secondly, the physical properties in the heterogeneous condensing flow are analyzed in detail by the particles number, radius, and types. The result presents that the foreign particles promote the heterogeneous condensation while the homogeneous condensation is weakened. Finally, the flow loss coefficients and thermal efficiency are calculated, and the guide to optimize compressor operation is proposed. It is concluded the heterogeneous condensation with liquid droplets as condensation nuclei can weaken the non-equilibrium condensation greatly and reach a higher thermal efficiency compared to the heterogeneous condensation with solid particles as condensation nuclei. The huge amount of air mass flow rate in compressors and expanders used in the CAES systems makes it difficult to filter out the solid particles and to dry air therefore, investigating the impact of steam condensation on the flow characteristics is recommended.

Application of Underwater Constant Pressure Compressed Air Energy Storage Technology in The Direction of Hydrogen Production

With the growing global demand for renewable energy to cope with climate change and energy security issues, underwater compressed air energy storage technology has gradually attracted attention. At the same time, hydrogen production process, as an important support for green energy transition, is becoming one of the key links to achieve clean energy generation and storage. This paper aims to explore the connection between underwater compressed air energy storage technology and hydrogen production process, and put forward a device combining underwater compressed air energy storage and hydrogen production, so as to solve the problems of low efficiency and serious pollution in the traditional hydrogen production industry. In the past, scholars focused on microcosmic research in the direction of hydrogen production, and tended to the direction of catalyst. Based on this, this paper will study the case of underwater compressed air energy storage device, and conceive a new hydrogen production device to promote the collaborative application of sustainable energy and improve the integration efficiency and reliability of energy system.

Investment-based optimisation of energy storage design parameters in a grid-connected hybrid renewable energy system

Grid-connected hybrid renewable power systems with energy storage can reduce the intermittency of renewable power supply. However, emerging energy storage technologies need improvement to compete with lithium-ion batteries and reduce the cost of energy. Identifying and optimising the most valuable improvement path of these technologies is challenging due to the non-linearity of the energy system model when considering parameters as independent variables. To overcome this challenge, a novel investment-based optimisation method is proposed. The method involves linear optimisation of the hybrid renewable energy system and subsequent investment optimisation, accounting for diminishing improvements per investment. The results from applying the investment-based optimisation to thermal energy, pumped thermal energy, molten salt, and adiabatic compressed air energy storage technologies, show that improving the discharge efficiency is the most valuable for all technologies. The second most important parameters are the costs of discharge capacity and energy storage capacity, and the least important parameters are the charge capacity cost and charge efficiency. The study provides detailed improvement pathways for each technology under various operational conditions, assisting developers in resource allocation. Overall, the investment-based optimisation method and findings contribute to enhancing the competitiveness of emerging energy storage technologies and reducing reliance on batteries in renewable energy systems.

Experimental Research on the Output Performance of Scroll Compressor for Micro Scale Compressed Air Energy Storage System

Micro compressed air energy storage systems are a research hotspot in the field of compressed air energy storage technology. Compressors and expanders are the core equipment for energy conversion, and their performance has a significant impact on the performance of the entire compressed air energy storage system. Scroll compressors have the advantages of small size, low noise, light weight, low vibration, long service life, continuous and stable gas transmission, and reliable operation. This article builds a micro compressed air energy storage system based on a scroll compressor and studies the effects of key parameters such as speed, torque, current, and storage tank pressure on the temperature difference, pressure ratio, energy consumption, and efficiency of the scroll compressor. The experimental results indicate that the power consumption of the scroll compressor shows an increasing trend with the increase in current, torque, and gas storage tank pressure. The isentropic efficiency of a scroll compressor shows a decreasing trend with increasing current, torque, and storage tank pressure. The maximum values of power consumption and isentropic efficiency of the scroll compressor are 3427 W and 90.8%, respectively.

Process design, integration, and optimization of a novel compressed air energy storage for the coproduction of electricity, cooling, and water

The use of fluctuating renewable energy over a certain threshold may lead to an unmanageable mismatch between the electricity generation and demand profiles threatening the grid's stability. In this study, an innovative complex energy storage/conversion system is proposed for the cogeneration of electricity, cooling, and water by integrating the liquefied natural gas (LNG) regasification process, an organic Rankine cycle, a compressed air energy storage (CAES) system, and a multi-effect distillation unit. The study attempts to minimize the CO2 emission from the CAES technology while addressing interruptions and reductions in the grid upon the extensive use of intermittent renewables. In addition, the proposed system uses excess power and waste heat during the charging and discharging of the CAES to regasify LNG and produce fresh water. The reference system performance is analyzed considering thermodynamic, economic, and environmental perspectives. The multi-objective grasshopper optimization algorithm is used to make a trade-off between the technical, economic, and environmental performance factors of the system. The results show an exergy efficiency of 50.6 % and a total cost rate of 322.8 $/h for the proposed system at the TOPSIS optimal point. The Grassmann diagram indicates the combustion chamber is the main source of irreversibility, and the Chord diagram revealed the discharge unit was responsible for more than 55 % of the total cost.

Compressed Air Energy Storage (CAES) and Liquid Air Energy Storage (LAES) Technologies—A Comparison Review of Technology Possibilities

This paper introduces, describes, and compares the energy storage technologies of Compressed Air Energy Storage (CAES) and Liquid Air Energy Storage (LAES). Given the significant transformation the power industry has witnessed in the past decade, a noticeable lack of novel energy storage technologies spanning various power levels has emerged. To bridge this gap, CAES and LAES emerge as promising alternatives for diverse applications. The paper offers a succinct overview and synthesis of these two energy storage methods, outlining their core operational principles, practical implementations, crucial parameters, and potential system configurations. The article also highlights approaches to enhance the efficiency of these technologies and underscores the roles of thermal energy storage within their processes. Furthermore, it delves into the discussion of the significance of hybrid systems and polygeneration in the contexts of CAES and LAES technologies. Moreover, we briefly explore the potential integration of these technologies into other power systems.

Thermodynamic analysis of isothermal compressed air energy storage system with droplets injection

Compressed air energy storage (CAES) is regarded as an effective long-duration energy storage technology to support the high penetration of renewable energy in the gird. Many types of CAES technologies are developed. The isothermal CAES (I-CAES) shows relatively high round-trip efficiency and energy density potentially. The isothermal processes of compression and expansion are realized by injecting water droplets into the compressor/expander cylinders. The compression heat is absorbed to abate temperature increase, and extra heat is added to abate temperature decrease during expansion. Firstly, the thermodynamic model of the I-CAES system using droplet injection method was established, and the calculation formula of droplet mass with rotation angle and air quality was given. The simulation modelling was verified by experimental results. The effects of gas-liquid mass ratio (ML) and rotation speed on thermodynamic performances including isothermal compression/expansion efficiency, isothermality, round-trip efficiency and energy density were studied. Results showed that isothermal compression/expansion efficiency, round-trip efficiency and isothermality were increased by increasing ML and reducing rotation speed, while, ML had the more obvious influence. When charging time was 6 h, discharging time was 4 h and ML equaled 10, round-trip efficiency of the one-stage I-CAES system was 83.15 % and energy density was 1.94 MJ/m3. Round-trip efficiency of the two-stage I-CAES system was 82.53 % and the energy density was 39.93 MJ/m3 under the same conditions.

Performance study of the supplemental combustion type compressed air energy storage system

Compressed air energy storage technology is considered to be the most promising energy storage technology, but it has not been applied commercially on a large scale, partly because of the low system efficiency, with the existing efficiency being about 70%. To improve the round trip efficiency of the system, this paper proposes a supplementary combustion compressed air energy storage system based on adiabatic compressed air energy storage. The system adds supplementary combustion equipment to increase expansion machines’ inlet air temperature by burning fuels such as syngas, hydrogen, and natural gas to increase the power generation of the system. The thermodynamic performance analysis has been conducted through the thermodynamic model of the system, and the effects of parameters such as compressor discharge temperature, supplementary combustion, and air-fuel ratio on the system performance have been further investigated. The research results show that the efficiency of the system is improved by nearly 6% compared with the conventional adiabatic compressed air energy storage system. Meanwhile, the system’s round-trip efficiency can be further increased by appropriately raising the compressor discharge temperature and supplemental combustion quantity.

AHP algorithm used to select suitable abandoned underground mines for energy storage infrastructure – iCAES technology. A specific case study for León (Spain)

In the energy transition, the promotion of renewable sources entails the development of storage technologies to manage the mismatch between energy production and demand. In this scenario, the use of CAES (Compressed Air Energy Storage) technology enables the efficient and cost-effective storage of large amounts of energy. However, this technology is developed in salt domes who have an inherent risk associated of underground exploration phase. To address this, we propose to develop an infrastructure (iCAES) in abandoned underground mines, where the exploration phase is completed and well known. For its implementation, this paper defines a structure hierarchization method gathers the technical and socio-economic criteria. It involves a multi-criteria problem, and the correct selection of the location must be based on specific mathematical algorithms. For this case the Analytic Hierarchy Process (AHP) from multi-criteria decision making (MCDM) methods allows quantified by means of a scientific and mathematical scale and the assignment of weights, so that it is possible to evaluate different alternatives. This is possible thanks to the application of the AHP model in absolute terms. The information gathering has been based on the specific case study of coal basins in the north of Spain, in the region of León. Considering the proposed methodology, the most suitable alternative locations to implement iCAES in the region of León were identified.

Thermo-dynamic and economic analysis of a novel pumped hydro-compressed air energy storage system combined with compressed air energy storage system as a spray system

The efficiency of adiabatic compressed air energy storage technology is limited by the low utilization of thermal energy in the energy storage room. Therefore, a pumped hydro-compressed air energy storage system combined with a compressed air energy storage system as a spray system is introduced in the present research and analyzed by thermodynamic and economic analysis to verify the feasibility of system. For the performance analysis of the system, the main components and the whole system are precisely analyzed from the thermodynamic point. The results show that the round-trip efficiency and total exergy efficiency of the system are 52.45% and 77.8%. The system can significantly improve the air temperature in the air storage room, reduce the pressure energy loss of the system, and increase the energy storage capacity. Moreover, achieving high system round-trip efficiency is dependent on components of the system with high efficiencies. By optimization of the system operation mode, the round-trip efficiency of the system can reach 56%.

Effect of relative humidity on the nozzle performance in non-equilibrium condensing flows for improving the compressed air energy storage technology

Compressed air energy storage (CAES) is now becoming the focus of a lot of research as it offers broad application possibilities and enormous economic benefits in terms of environmental protection and life with low-carbon emissions. The compressor performance is closely related to energy storage efficiency in CAES. Considering the significant role of water components inside the flow of the compressor, the flow mechanism in transonic with non-equilibrium condensation should be explored in detail. First, a blend condensation model is presented with the effect of the entire Knudsen number range on droplet growth, to explore condensation flow characteristics more clearly. Moreover, the influence of relative humidity (RH) on the nucleation and droplet growth and condensation shock wave is analysed with the blend model. Finally, flow loss is calculated in the de Laval nozzle, and the direction to optimize the compressor efficiency is indicated by considering the RH conditions and wall curvature arcs. The contribution of these factors to the flow loss deserves careful consideration. The analysis conducted in the paper shows the effect of relative humidity on the nozzle, and the conclusions obtained provide meaningful reference for improving the performance of compressors used in the CAES process in the future.