Large-scale Compressed Air Energy Storage Research Articles

Pressure response of large-scale compressed air energy storage in porous formations

Large-scale compressed air energy storage (CAES) in porous formations can contribute to compensate the strong daily fluctuations in renewable energy production. This work presents a hypothetical CAES scenario using a representative geological anticlinal structure in Northern Germany and performs numerical simulations to estimate pressure response in the storage formation. The results show that the induced pressure changes laterally throughout the storage formation are due to initial fill of the air storage. Because of high air compressibility, the pressure fluctuations caused by daily cyclic operation can only be observed in the gas phase which reaches a distance of roughly 500 m.

Thermal System Analysis and Optimization of Large-Scale Compressed Air Energy Storage (CAES)

As an important solution to issues regarding peak load and renewable energy resources on grids, large-scale compressed air energy storage (CAES) power generation technology has recently become a popular research topic in the area of large-scale industrial energy storage. At present, the combination of high-expansion ratio turbines with advanced gas turbine technology is an important breakthrough in energy storage technology. In this study, a new gas turbine power generation system is coupled with current CAES technology. Moreover, a thermodynamic cycle system is optimized by calculating for the parameters of a thermodynamic system. Results show that the thermal efficiency of the new system increases by at least 5% over that of the existing system.

Economic analysis of using above ground gas storage devices for compressed air energy storage system

Above ground gas storage devices for compressed air energy storage (CAES) have three types: air storage tanks, gas cylinders, and gas storage pipelines. A cost model of these gas storage devices is established on the basis of whole life cycle cost (LCC) analysis. The optimum parameters of the three types are determined by calculating the theoretical metallic raw material consumption of these three devices and considering the difficulties in manufacture and the influence of gas storage device number. The LCCs of the three types are comprehensively analyzed and compared. The result reveal that the cost of the gas storage pipeline type is lower than that of the other two types. This study may serve as a reference for designing large-scale CAES systems.

Porous Media Compressed-Air Energy Storage (PM-CAES): Theory and Simulation of the Coupled Wellbore–Reservoir System

Expansion in the supply of intermittent renewable energy sources on the electricity grid can potentially benefit from implementation of large-scale compressed air energy storage in porous media systems (PM-CAES) such as aquifers and depleted hydrocarbon reservoirs. Despite a large government research program 30 years ago that included a test of air injection and production in an aquifer, and an abundance of literature on CAES mostly relevant to caverns, there remain fundamental questions about the hydrologic and energetic performance of PM-CAES. We have developed rigorous simulation capabilities for PM-CAES that include modeling the coupled wellbore–reservoir system. Through consideration of a prototypical PM-CAES wellbore–reservoir system representing a depleted hydrocarbon reservoir, we have simulated 100 daily cycles of PM-CAES. We find that (1) PM-CAES can store energy but that pervasive pressure gradients in PM-CAES result in spatially variable energy storage density in the reservoir, (2) the wellbore–reservoir storage component of PM-CAES is very efficient, (3) cap-rock and hydrologic seals along with proper sizing of the PM-CAES reservoir prevent excess pressure diffusion from being a problem, and (4) injection and production of air does not significantly mobilize residual liquid water in the reservoir.

Potential and Evolution of Compressed Air Energy Storage: Energy and Exergy Analyses

Energy storage systems are increasingly gaining importance with regard to their role in achieving load levelling, especially for matching intermittent sources of renewable energy with customer demand, as well as for storing excess nuclear or thermal power during the daily cycle. Compressed air energy storage (CAES), with its high reliability, economic feasibility, and low environmental impact, is a promising method for large-scale energy storage. Although there are only two large-scale CAES plants in existence, recently, a number of CAES projects have been initiated around the world, and some innovative concepts of CAES have been proposed. Existing CAES plants have some disadvantages such as energy loss due to dissipation of heat of compression, use of fossil fuels, and dependence on geological formations. This paper reviews the main drawbacks of the existing CAES systems and presents some innovative concepts of CAES, such as adiabatic CAES, isothermal CAES, micro-CAES combined with air-cycle heating and cooling, and constant-pressure CAES combined with pumped hydro storage that can address such problems and widen the scope of CAES applications, by energy and exergy analyses. These analyses greatly help us to understand the characteristics of each CAES system and compare different CAES systems.

Thermodynamic and hydrodynamic response of compressed air energy storage reservoirs: a review

Installation of large-scale compressed air energy storage (CAES) plants requires underground reservoirs capable of storing compressed air. In general, suitable reservoirs for CAES applications are either porous rock reservoirs or cavern reservoirs. Depending on the reservoir type, the cyclical action of air injection and subsequent withdrawal produces temperature and pressure fluctuations within the reservoir. An accurate prediction of these fluctuations is essential for the design of the reservoir and its associated turbomachinery. Being mutually dependent, the selection of the turbomachinery and reservoir characteristics must be conducted simultaneously to obtain an integrated cost-effective plant. The present review is intended to encompass the pertinent literature on the temperature and pressure variations within CAES reservoirs. The principal experimental and operational data sources are described, as well as important results of theoretical modeling efforts. Conclusions derived from those investigations and their relevance to CAES plant designs are discussed.

Energy and exergy analysis of a micro-compressed air energy storage and air cycle heating and cooling system

Energy storage systems are becoming more important for load leveling, especially for widespread use of intermittent renewable energy. Compressed air energy storage (CAES) is a promising method for energy storage, but large scale CAES is dependent on suitable underground geology. Micro-CAES with man-made air vessels is a more adaptable solution for distributed future power networks. In this paper, energy and exergy analyses of a micro-CAES system are performed, and, to improve the efficiency of the system, some innovative ideas are introduced. The results show that a micro-CAES system could be a very effective system for distributed power networks as a combination that provides energy storage, generation with various heat sources, and an air-cycle heating and cooling system, with a energy density feasible for distributed energy storage and a good efficiency due to the multipurpose system. Especially, quasi-isothermal compression and expansion concepts result in the best exergy efficiencies.

Can large-scale advanced-adiabatic compressed air energy storage be justified economically in an age of sustainable energy?

This article explores whether large-scale compressed air energy storage can be justified technically and economically in an era of sustainable energy. In particular, we present an integrated energy and exergy analysis of an idealized case of an advanced-adiabatic compressed air energy storage system and estimate its cycle efficiency. Based on our results, advanced-adiabatic compressed air energy storage (AA-CAES) seems to be technically feasible with a cycle efficiency of roughly 50% or better. However, our calculation shows that AA-CAES may not be as economically attractive as underground pumped hydro storage.