As mitigating climate change becomes an increasing worldwide focus, it is vital to explore a diverse range of technologies for reducing emissions. Heating and cooling make up a significant proportion ...of energy demand, both domestically and in industry. An effective method of reducing this energy demand is the storage and use of waste heat through the application of seasonal thermal energy storage, used to address the mismatch between supply and demand and greatly increasing the efficiency of renewable resources. Four methods of sensible heat storage; Tank, pit, borehole, and aquifer thermal energy storage are at the time of writing at a more advanced stage of development when compared with other methods of thermal storage and are already being implemented within energy systems. This review aims to identify some of the barriers to development currently facing these methods of seasonal thermal energy storage, and subsequently some of the work being undertaken to address these barriers in order to facilitate wider levels of adoption throughout energy systems.
•Review of aquifer, borehole, tank, and pit seasonal thermal energy storage.•Identifies barriers to the development of each technology.•Advantages and disadvantages of each type of STES.•Waste heat for seasonal thermal storage.•Storage temperatures, recovery efficiencies, and uses for each technology.
•This article describes the costs of Pumped Heat Energy Storage.•The technology is compared with all other major grid-scale energy storage solutions.•Levelised Costs of Storage is between 8.9 and ...11.4€ct/kWh.•The technology could prove competitive with Pumped Hydro but more flexible.•Three scenarios were considered based on a grid-scale demonstrator.
Future electricity systems which plan to use large proportions of intermittent (e.g. wind, solar or tidal generation) or inflexible (e.g. nuclear, coal, etc.) electricity generation sources require an increasing scale-up of energy storage to match the supply with hourly, daily and seasonal electricity demand profiles. Evaluation of how to meet this scale of energy storage has predominantly been based on the deployment of a handful of technologies including batteries, Pumped Hydroelectricity Storage, Compressed Air Energy Storage and Power-to-Gas. However, for technical, confidentiality and data availability reasons the majority of such analyses have been unable to properly consider and have therefore neglected the potential of Pumped Heat Energy Storage, which has thus not been benchmarked or considered in a much detail relative to competitive solutions. This paper presents an economic analysis of a Pumped Heat Energy Storage system using data obtained during the development of the world’s first grid-scale demonstrator project. A Pumped Heat Energy Storage system stores electricity in the form of thermal energy using a proprietary reversible heat pump (engine) by compressing and expanding gas. Two thermal storage tanks are used to store heat at the temperature of the hot and cold gas. Using the Levelised Cost of Storage method, the cost of stored electricity of a demonstration plant proved to be between 2.7 and 5.0€ct/kWh, depending on the assumptions considered. The Levelised Cost of Storage of Pumped Heat Energy Storage was then compared to other energy storage technologies at 100MW and 400MWh scales. The results show that Pumped Heat Energy Storage is cost-competitive with Compressed Air Energy Storage systems and may be even cost-competitive with Pumped Hydroelectricity Storage with the additional advantage of full flexibility for location. As with all other technologies, the Levelised Cost of Storage proved strongly dependent on the number of storage cycles per year. The low specific cost per storage capacity of Pumped Heat Energy Storage indicated that the technology could also be a valid option for long-term storage, even though it was designed for short-term operation. Based on the resulting Levelised Cost of Storage, Pumped Heat Energy Storage should be considered a cost-effective solution for electricity storage. However, the analysis did highlight that the Levelised Cost of Storage of a Pumped Heat Energy Storage system is sensitive to assumptions on capital expenditure and round trip efficiencies, emphasising a need for further empirical evidence at grid-scale and detailed cost analysis.
•Current state of developments in carbon dioxide storage is reviewed.•The main carbon dioxide storage options and challenges are presented.•Public acceptance of CO2 storage play a central role in ...technology deployment.•Major carbon dioxide storage projects are summarised.•Future outlook for carbon dioxide storage is suggested.
Carbon capture and storage (CCS) has been identified as an urgent, strategic and essential approach to reduce anthropogenic CO2 emissions, and mitigate the severe consequences of climate change. CO2 storage is the last step in the CCS chain and can be implemented mainly through oceanic and underground geological sequestration, and mineral carbonation. This review paper aims to provide state-of-the-art developments in CO2 storage. The review initially discussed the potential options for CO2 storage by highlighting the present status, current challenges and uncertainties associated with further deployment of established approaches (such as storage in saline aquifers and depleted oil and gas reservoirs) and feasibility demonstration of relatively newer storage concepts (such as hydrate storage and CO2-based enhanced geothermal systems). The second part of the review outlined the critical criteria that are necessary for storage site selection, including geological, geothermal, geohazards, hydrodynamic, basin maturity, and economic, societal and environmental factors. In the third section, the focus was on identification of CO2 behaviour within the reservoir during and after injection, namely injection-induced seismicity, potential leakage pathways, and long-term containment complexities associated with CO2-brine-rock interaction. In addition, a detailed review on storage capacity estimation methods based on different geological media and trapping mechanisms was provided. Finally, an overview of major CO2 storage projects, including their overall outcomes, were outlined. This review indicates that although CO2 storage is a technically proven strategy, the discussed challenges need to be addressed in order to accelerate the deployment of the technology. In addition, beside the necessity of techno-economic aspects, public acceptance of CO2 storage plays a central role in technology deployment, and the current ethical mechanisms need to be further improved.
Due to humanity's huge scale of thermal energy consumption, any improvements in thermal energy management practices can significantly benefit the society. One key function in thermal energy ...management is thermal energy storage (TES). Following aspects of TES are presented in this review: (1) wide scope of thermal energy storage field is discussed. Role of TES in the contexts of different thermal energy sources and how TES unnecessitates fossil fuel burning are explained. Solar power generation, building thermal comfort and other niche applications of TES are presented. (2) Insight into classes of TES storage materials with details like their physical properties, cost, operational performance and suitability to application requirements is provided. (3) Insight into types of TES systems is presented. TES systems are classified using different types of criteria. Most common TES systems like seasonal TES systems, CSP plant TES systems, TES systems of domestic solar thermal applications, heat and cold storages of building HVAC systems etc are described. Active TES systems like thermocline, packed bed, fluidized bed, moving bed etc are analyzed. Passive TES systems implemented in buildings, textiles, automobiles etc are presented. TES systems operating in cold, low, medium and high temperature ranges are listed. Design parameters, operational issues and cost model of TES systems are discussed.
•Technology, material and research works in thermal energy storage were summarized.•Thermal properties of thermal energy storage materials were presented and analyzed.•Heat storage mechanism and applications based TES systems were shown in detail.•Performance parameters and operational issues based TES systems were discussed.
Energy storage systems: a review Mitali, J.; Dhinakaran, S.; Mohamad, A.A.
Energy Storage and Saving,
September 2022, Volume:
1, Issue:
3
Journal Article
Peer reviewed
Open access
The world is rapidly adopting renewable energy alternatives at a remarkable rate to address the ever-increasing environmental crisis of CO2 emissions. Renewable energy system offers enormous ...potential to decarbonize the environment because they produce no greenhouse gases or other polluting emissions. However, the RES relies on natural resources for energy generation, such as sunlight, wind, water, geothermal, which are generally unpredictable and reliant on weather, season, and year. To account for these intermittencies, renewable energy can be stored using various techniques and then used in a consistent and controlled manner as needed. Several researchers from around the world have made substantial contributions over the last century to developing novel methods of energy storage that are efficient enough to meet increasing energy demand and technological breakthroughs. This review attempts to provide a critical review of the advancements in the energy storage system from 1850–2022, including its evolution, classification, operating principles and comparison.
In the past decade, long-term sorption and thermochemical heat storage has generated lot of interest. This paper presents the state of the art in this field of research, materials used in these ...systems and technological difficulties that researchers are set against. An emphasis is put on recent demonstrative projects including absorption and adsorption for long-term solar energy storage. It emerges that considerable breakthrough have been made. Even though there is no mature long-term sorption or thermochemical energy storage yet, primarily due to the high cost of materials, the suitability of this technology to long-term storage remains its main power of attracting.
For solving the global problems of environmental pollution and energy shortages, thermal energy storage system that can improve the efficiency and utilization ratio of energy and solve the gap ...between energy demand and supply, has received more attention in recent years. More specifically, the latent thermal storage systems that use phase change materials (PCMs) as storage media, possessing high latent heat storage density and almost constant phase change temperature are the focus area in thermal energy storage. Previously, most of the researches on PCMs were organic, however in recent years, inorganic PCMs with large phase change temperature range have been paid more and more attention. In common inorganic PCMs, hydrated salts possess lower phase change temperature, applying in buildings, solar water heating systems, textiles, etc., and molten salts and metals have higher phase change temperature, applying in concentrated solar power (CSP) generation and industrial waste heat recovery etc. Each has its own outstanding merits, for example, inorganic salts possess a large latent heat storage capacity and metals possess an extremely high thermal conductivity. Therefore, this review focuses on the researches of inorganic PCMs in recent years and summaries their thermal properties, and introduces the integration of inorganic PCMs into heat exchangers and some applications of inorganic PCMs in main systems, seeking to give readers a relatively comprehensive awareness on them.
•Thermal properties of inorganic PCMs for thermal energy storage are analyzed.•Performances of heat exchangers integrated into inorganic PCMs are summarized.•Applications of inorganic PCMs in thermal energy storage systems are discussed.
•A novel ladder-shaped fin is proposed to accelerate melting process.•Compared to original straight fin, a maximal 52.2% of melting time can be saved.•Fin angle has a significant effect on reducing ...melting time of the whole PCM.•36.8% reduction in melting time is obtained if turning fins by 45° anticlockwise.•It is more profitable to add fins to mobile heat carrier than to have no fins.
Latent heat energy storage system provides an alternative solution to solving the imbalance problem of energy supply and demand. To improve the phase change efficiency, a novel ladder-shaped fin is proposed to accelerate melting process. Under the same mass of fin materials, two groups of fin shapes (totally eight cases) are innovatively designed. Upon being verified by experiments in literature, numerical models account for comprehensive descriptions on melting front propagation with emphasizing temperature development and free convection in the liquid phase. Results demonstrate that the ladder-shaped fins can better optimize the melting channel of phase change material than the straight fin. Compared to the original straight fin case, a maximal 52.2% of the total melting time can be saved. The angle change of fins has a significant effect on reducing the melting time of the whole PCM. In Group I where fins are arranged vertically and horizontally, the total melting time is much shorter than that of each corresponding case in Group II (45° from the vertical axis). For the original straight fin in Group II, a 36.8% reduction in total melting time is obtained if turning fins by 45°clockwise. To be conclusive, it is more beneficial to add fins to mobile heat accumulators than to have no fins, saving more energy charging time.
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