Chemical Energy Storage Technologies Research Articles

Comparison of green ammonia and green hydrogen pathways in terms of energy efficiency

The global energy system transition necessitates new energy carriers with low greenhouse gas emissions. Chemical energy storage technologies provide a viable basis for long-term energy storage. Ammonia is a promising approach in this regard. This study takes a closer look on the energetic potential of ammonia as energy carrier compared to hydrogen. The efficiencies of five green ammonia and four green hydrogen pathways are evaluated for production, storage and utilisation on a power-to-X-to-power basis. The round-trip efficiency for each pathway is calculated by comparing the energy demand that each individual technology requires along the pathways and the usable electric energy that is provided at the end of the pathways. The most efficient pathway for ammonia turns out to be a combination of a decomposition-unit and a solid-oxide fuel cell with a round-trip efficiency of 28 ± 5 % for 30-day storage duration. This is similar to the value for the most efficient pathway using hydrogen. Pathways utilising ammonia are energetically particularly beneficial compared to the hydrogen pathways in case of long storage duration.

Energy storage systems review and case study in the residential sector

Energy storage is recognized as an increasingly important parameter in the electricity and energy systems, allowing the generation flexibility and therefore the demand side management. It can contribute to optimal use of generation and grid assets, and support emissions reductions in various economic sectors. Energy storage can support the European Union (EU) targets for efficient use of energy by helping to ensure energy security, a well-functioning internal energy market, and successful implementation of more carbon-cutting renewables online. By strengthen the use of energy storage, the EU can decrease its energy imports, improve the efficiency of the energy system, and keep prices low by better integrating variable renewable energy sources. Moreover energy storage can contribute to better use of renewable energy sources in the energy system since it can store energy produced when the conditions for renewable energy are appropriate but demand may be low. In this framework, primary objective of this study is the investigation, the comparative analysis and the evaluation according to specific criteria of the current thermal energy storage systems. Electrical, electrochemical, thermal, mechanical and chemical energy storage technology and systems are extensively presented and categorized in terms of their advantages and disadvantages as well as in terms of their technical and financial characteristics. This paper also presents the implementation of thermal energy storage in the residential sector. More specifically is examining the application of a phase change material storage system into the building’s walls cavity. The study focuses on the contribution of the applied energy storage system to the overall increase of the energy efficiency of the building.

Economic viability of SNG production from power and CO2

Power-to-Gas is a chemical energy storage technology based on converting electrical energy into chemical energy in the form of a certain gas, typically hydrogen or methane. The main advantage of methane, namely synthetic natural gas (SNG), is that in this way the already existing gas infrastructure can be used as transport and storage medium. This article evaluates the economic viability of SNG production from CO2 capture and utilization. As representative examples, California, Ontario, Spain, Sweden, Paraguay, Germany and India electricity markets were considered. At present, the estimated cost of SNG is 70–125 EUR/MWh, from 2 to 7 times higher than fossil natural gas. In a feasible future scenario, the costs can be reduced to 40 EUR/MWh, competing directly with the fossil fuel, especially in countries where it is mainly imported as Germany or Spain. To achieve this goal, further R&D is needed, especially on two key parameters: electrolysis efficiency and methanation capex costs. In any case, the economic viability of SNG is subject to high annual operating hours in order to return the initial investment. Therefore, the SNG process, rather than an intermittent grid storage technology, seems a promising in continuously or seasonal production, having a unique niche market among energy storage technologies.

Energy Storage as Part of a Secure Energy Supply

AbstractThe current energy system is subject to a fundamental transformation: A system that is oriented towards a constant energy supply by means of fossil fuels is now expected to integrate increasing amounts of renewable energy to achieve overall a more sustainable energy supply. The challenges arising from this paradigm shift are currently most obvious in the area of electric power supply. However, it affects all areas of the energy system, albeit with different results. Within the energy system, various independent grids fulfill the function of transporting and spatially distributing energy or energy carriers, and the demand‐oriented supply ensures that energy demands are met at all times. However, renewable energy sources generally supply their energy independently from any specific energy demand. Their contribution to the overall energy system is expected to increase significantly. Energy storage technologies are one option for temporal matching of energy supply and demand. Energy storage systems have the ability to take up a certain amount of energy, store it in a storage medium for a suitable period of time, and release it in a controlled manner after a certain time delay. Energy storage systems can also be constructed as process chains by combining unit operations, each of which cover different aspects of these functions. Large‐scale mechanical storage of electric power is currently almost exclusively achieved by pumped‐storage hydroelectric power stations. These systems may be supplemented in the future by compressed‐air energy storage and possibly air separation plants. In the area of electrochemical storage, various technologies are currently in various stages of research, development, and demonstration of their suitability for large‐scale electrical energy storage. Thermal energy storage technologies are based on the storage of sensible heat, exploitation of phase transitions, adsorption/desorption processes, and chemical reactions. The latter offer the possibility of permanent and loss‐free storage of heat. The storage of energy in chemical bonds involves compounds that can act as energy carriers or as chemical feedstocks. Thus, they are in direct economic competition with established (fossil fuel) supply routes. The key technology here – now and for the foreseeable future – is the electrolysis of water to produce hydrogen and oxygen. Hydrogen can be transformed by various processes into other energy carriers, which can be exploited in different sectors of the energy system and/or as raw materials for energy‐intensive industrial processes. Some functions of energy storage systems can be taken over by industrial processes. Within the overall energy system, chemical energy storage technologies open up opportunities to link and interweave the various energy streams and sectors. Chemical energy storage not only offers means for greater integration of renewable energy outside the electric power sector, it also creates new opportunities for increased flexibility, novel synergies, and additional optimization. Several examples of specific energy utilization are discussed and evaluated with respect to energy storage applications.The article describes various technologies for energy storage and their potential applications in the context of Germany's Energiewende, i.e. the transition towards a more sustainable energy system. Therefore, the existing legal framework defines some of the discussions and findings within the article, specifically the compensation for renewable electricity providers defined by the German Renewable Energy Sources Act, which is under constant reformation. While the article is written from a German perspective, the authors hope this article will be of general interest for anyone working in the areas of energy systems or energy technology.

Vanadium Redox Battery System and Its Energy Storage Application in Wind Farm

The energe storage system with combination of large-scale grid-connected wind farms will be the developing trend of renewable energy in future. The flow battery has becoming the most potential advanced chemical energy storage technology among the storage method. This paper is mainly introducing about the work principle, characteristics and structure of the VRB system. Futhermore, the control mechanism of the power quality and stability used in wind farm connected to power grid by battery energy storage is illustrated in the end of paper.

Application of Chemical Storage in Smart Grid and Analysis on Loss Reduction

Because of the characteristic of highly controllability and modularization, battery energy storage could be widely applied in the distributed renewable energy generation for improving the reliability of power supply and smoothing the load. The paper introduces the chemical energy storage technology especially the flow battery and designs the model of smart grid with the chemical energy storage devices. Then the paper gives the interface circuit between smart grid and energy storage, and simulates an actual distribution network with chemical energy storage device, the result shows that if the energy storage battery with proper capacity was connected to the distribution network at a proper position, it was effective in reducing the line loss.