Electrical Storage Technologies Research Articles

The Storage Process of Electric Energy Produced from Renewable Sources from Hydrogen to Domestic Hot Water Heating

The expansion of renewable electricity storage technologies, including green hydrogen storage, is spurred by the need to address the high costs associated with hydrogen storage and the imperative to increase storage capacity. The initial section of the paper examines the intricacies of storing electricity generated from renewable sources, particularly during peak periods, through green hydrogen. Two primary challenges arise: firstly, the complexity inherent in the storage technology and its adaptation for electricity reproduction; and secondly, the cost implications throughout the technological chain, resulting in a significant increase in the price of the reproduced energy. Electric energy storage emerges as a pivotal solution to accommodate the growing proportion of renewable energy within contemporary energy systems, which were previously characterized by high stability. During the transition to renewable-based energy systems, optimizing energy storage technology to manage power fluctuations is crucial, considering both initial capital investment and ongoing operational expenses. The economic analysis primarily focuses on scenarios where electricity generated from renewable sources is integrated into existing power grids. The subsequent part of this paper explores the possibility of localizing excess electricity storage within a specific system, illustrated by domestic hot water.

Solar Based Wireless Power Transmission for Electric vehicle Charging Station

Wireless power transfer (WPT) using magnetic resonance is the technology which could set human free from the annoying wires. In fact, the WPT adopts the same basic theory which has already been developed for at least 30 years with the term inductive power transfer. WPT technology is developing rapidly in recent years. At kilowatts power level, the transfer distance increases from several millimetres to several hundred millimetres with a grid to load efficiency above 90%. The advances make the WPT very attractive to the electric vehicle (EV) charging applications in both stationary and dynamic charging scenarios. For energy, environment, and many other reasons, the electrification for transportation has been carrying out for many years. In railway systems, the electric locomotives have already been well developed for many years. A train runs on a fixed track. It is easy to get electric power from a conductor rail using pantograph sliders. However, for electric vehicles (EVs), the high flexibility makes it not easy to get power in a similar way. Instead, a high power and large capacity battery pack is usually equipped as an energy storage unit to make an EV to operate for a satisfactory distance. The problem for an electric vehicle is nothing else but the electricity storage technology, which requires a battery which is the bottleneck today due to its unsatisfactory energy density, limited lifetime and high cost. Keywords: Wireless Power transfer, Electric Vehicle, Battery

Renewable green oil as a low-cost option for large-scale, long duration energy storage to produce on-demand electricity

<p class="MsoNormal" style="text-align: justify;"><span style="font-size: 14pt; font-family: 'times new roman', times, serif;">The rapid growth of renewable solar and wind energy necessitates extensive, long-term energy storage solutions to stabilize the electric grid and address the intermittent nature of these sources. In the absence of cost-effective long-duration, large-scale (LDLS) energy storage, there is a risk of increased disruptive blackouts and brownouts as intermittent energy sources approach 50% of electricity generation. Our analysis underscores volumetric energy density as a pivotal determinant in LDLS energy storage solutions, which is particularly crucial during periods of diminished renewable resource availability, such as the rainy season. Despite emphasis on conventional electric batteries and mechanical storage technologies such as compressed air and pumped hydro for LDLS, their costs pose a significant obstacle to widespread adoption, especially in emerging economies. In this study, we present a groundbreaking approach to LDLS: on-demand electricity generation from carbon-neutral renewable oil, known as "green oil," leveraging Reliance’s innovative catalytic hydrothermal liquefaction (R-CAT-HTL) technology. Our investigation evaluated two distinct sources of green oil production: organic waste streams (e.g., municipal solid waste, agricultural-waste, etc.) and on purpose production of algal biomass. We demonstrate that burning renewable green oil to produce electricity offers a cost-effective solution for large-scale (GWh) long-duration (many days) energy storage, ensuring the stability, reliability, and resiliency of the electric grid. We also demonstrate that minimum 14 days, ideally 30 days energy storage is needed for continuous uninterrupted service, especially critical for manufacturing facilities. Through a meticulous levelized cost of storage (LCOS) analysis comparing green oil with other LDLS technologies reported in literature, we demonstrate the cost effectiveness of green oil. In this model, green oil serves as stored energy, functions akin to a battery and is efficiently converted into electricity through conventional reciprocating engines or next-generation more efficient turbines. Our findings suggest that green oil derived from diverse organic sources is the most economically viable option for GWh-scale storage, particularly when storage requirements extend beyond a single day. This research thus presents a transformative cost-effective solution to the pressing challenge of LDLS energy storage, accelerating a sustainable and resilient energy future.</span></p>

Toward a physical Dodge City high voltage direct current (HVDC) electricity hub

A physical Dodge City high voltage direct current (HVDC) electricity commodity hub would foster the kind of risk transfer that would invite the full participation of the financial industry in an interstate transmission system essential to the speedy development of renewable electricity and complementary storage technologies. Obstacles lie in the way of such a vision, however. Chief among them, paradoxically, is the administrative system that has evolved since the late 1990 s to promote regional electricity markets. That system abstracts from investment risk and the nation’s uneven geography of renewable resources. It lodges a kind of monopoly planning and scheduling power in a small group of bureaucratic centralized system operators that mimics a command economy in their own distinct regions, not the kind of market economy that has traditionally driven investment in US interstate energy infrastructure. And yet, in dealing with the vexing transmission constraints faced by the renewable generating sector (the “queue”), the Federal Energy Regulatory Commission (FERC) continues to pursue ever greater authority for those regional transmission organizations (RTOs). Such FERC action regarding its RTOs in 2022–23 represents a highly evident case of path dependency—a problem—that state or federal policy makers wishing to speed the entry of large-scale renewable generation, and complementary storage technologies, will have find a way either to confront directly or to work around.

Off-grid vs. grid-based: Techno-economic assessment of a power-to-liquid plant combining solid-oxide electrolysis and Fischer-Tropsch synthesis

The economic performance of Power-to-Liquid processes depends substantially on the power source’s features, i.e., electricity costs and full load hours. Off-grid solutions can ensure cheap, green electricity without being exposed to fluctuating electricity markets. A techno-economic assessment of a Power-to-Liquid plant combining solid-oxide electrolysis and Fischer-Tropsch synthesis has been conducted. Off-grid and grid-based scenarios of three process configurations at plant scales from 1 to 1000 MWel. rated electrolyzer power were evaluated. Net production costs of Fischer-Tropsch products ranging from 2.42 to 4.56 €2022/kg were obtained for the grid-based scenarios. In contrast, values of 1.28 to 2.40 €2022/kg were determined for the evaluated off-grid scenarios. Scaling up the plant showed a weakened decrease in net production costs after surpassing a threshold of 100 MWel. due to substantial relative electricity costs of up to 88 %. Thus, future Power-to-Liquid projects should be designed at a scale of 100MWel. rated electrolyzer power. In addition, an availability exceeding 4000 h/a is recommended for off-grid plants, e.g., by implementing hybrid renewable power plants as well as electricity and syngas storage technologies.

Broad Range of Technologies Could Firm Up Wind and Solar Generation in Net Zero Carbon Dioxide Emission Electricity Systems

‘Firming’ technologies can be coupled to variable wind and solar generation to meet electricity demand reliably. Options that could participate in this firming role include dispatchable electricity generators, electricity storage technologies, atmospheric carbon dioxide removal, and demand management. In this study, we allow various firming technologies to participate in a stylized net zero CO2 emission electricity system reliant on wind and solar generation. By examining a series of least-cost systems in which the most valuable firming technologies are sequentially removed, we demonstrate that reliable wind-and-solar-reliant electricity systems do not depend on the feasibility of any particular firming technology.

Graphene-based anode materials in Li-Ion batteries

Doubtlessly, one of the most used electric power storage technologies at the moment is the lithium-ion battery (LIB). Meanwhile, in order to meet increasing needs for the present LIB performance, the improvement on the anode materials of LIB is one of the major study approaches. Among a wide range of options like silicon, metal oxides, and other compounds and mixtures, this review will mainly focus on the graphene-related LIB anode materials. By discussing the preparation processes and the electrochemical performance of various types of graphene-based and graphene-coated materials that are used for the anode of LIBs, the improvements of the addition of graphene in other materials have been reviewed, and the patterns of that have been analysed. This review helps summarize the current typical research results of the electrochemical properties of LIB anode materials based on graphene and gives suggestions about the future research focus on this specific category of materials by referring to the comparison of the data reviewed.

Attention-Focused Machine Learning Method to Provide the Stochastic Load Forecasts Needed by Electric Utilities for the Evolving Electrical Distribution System

Greater variation in electrical load should be expected in the future due to the increasing penetration of electric vehicles, photovoltaics, storage, and other technologies. The adoption of these technologies will vary by area and time, and if not identified early and managed by electric utilities, these new customer needs could result in power quality, reliability, and protection issues. Furthermore, comprehensively studying the uncertainty and variation in the load on circuit elements over periods of several months has the potential to increase the efficient use of traditional resources, non-wires alternatives, and microgrids to better serve customers. To increase the understanding of electrical load, the authors propose a multistep, attention-focused, and efficient machine learning process to provide probabilistic forecasts of distribution transformer load for several months into the future. The method uses the solar irradiance, temperature, dew point, time of day, and other features to achieve up to an 86% coefficient of determination (R2).

Inclusion of key social indices for a comparative assessment of the sustainability of the life cycle of current and future electricity generation in Spain: A proposed methodology

The purpose of this work is to offer a methodology for the introduction and consolidation of social indexes within a Life Cycle Sustainability Assessment for the evaluation of large-scale electricity production. This methodology is based on an interrelation of the UNEP subcategories with the global indicator framework for the Sustainable Development Goals, resulting in 9 categories of social impact quantified by 10 indexes. To evaluate the introduction of this methodology in an LCSA a study case is used. It is applied to obtain social indexes for the 2019, 2030 and 2050 Spanish electricity scenarios, which involve different electricity generation and storage technologies: involve coal, natural gas, nuclear, hydropower, wind, solar photovoltaic, concentrated solar, biomass and storage technologies. Within the study case, an environmental life cycle assessment is also conducted, while the impacts of the economic dimension are estimated by the levelized cost of energy. This study reveals that even before important qualitative information is brought to light, as should be done in any decision-making process, there are important gaps that can be filled in terms of quantitative information in an LCSA. To do so, it provides with a methodology to expand the number of social indexes normally used in this type of assessments with the purpose of contributing to decision processes with clarity and transparency. Labour rights, salary differences for the same position, diversity in executive positions, child labour, and R&D expenditure complement the previously used occupational injuries, fatalities due to large accidents, and direct employment. The proposed methodology is applied to a Spanish case study, demonstrating the benefits and disadvantages associated with the modification of the electricity mix. However, it also highlights significant information gaps in availability and transparency that need to be addressed in future research, as part of the path towards standardizing LCSA.

Comparative life cycle assessment of industrial demand-side management via operational optimization

Demand-side management (DSM) is a promising option to synchronize electricity demand with volatile electricity generation by renewable energy sources. For a comprehensive assessment of the environmental impacts of DSM, the holistic method of life cycle assessment (LCA) can be applied. However, not all purposes of industrial DSM are consistently defined in the functional unit, focusing either on the products or the flexible electricity consumption. We develop a method to jointly consider the products and the flexible electricity consumption in the functional unit of industrial DSM. To ensure a consistent LCA, we compare the DSM system with a reference system that provides the same functionality by operating the industrial process at steady state and utilizing electricity storage technologies to provide flexibility. We apply the proposed method on the switchable chlor-alkali electrolysis. The results show that the environmental impacts of applying DSM on the switchable electrolysis are comparable to integrating electricity storage.

Techno-economic evaluation of a Brayton battery configuration with power-to-heat extension

The development of cost-efficient, environmentally friendly, and reliable technologies for utility-scale electricity storage is a key element for future flexible power systems. Brayton cycle-based Pumped Thermal Energy Storage (PTES) offers the potential of making a substantial progress to reach this goal. For further improvements in cost efficiency and flexibility we investigate the additional integration of Power-to-Heat (PtH) into the heat pump cycle. This integration allows a reduction in component size due to higher energy density; however, it also leads to efficiency losses. The objective of this paper is to quantify this tradeoff between round-trip efficiency and cost efficiency for closed-cycle Joule-Brayton PTES configurations and to provide design solutions for the novel PtH component. To this end, a wide-range design study with variable electric heating power and component efficiencies is conducted. In addition to the thermodynamic analysis, an economic assessment is presented, which clarifies the benefits of PtH extension. The results demonstrate a significant reduction of capital expenditures by up to 23 % along with higher system flexibility and a loss in round-trip efficiency of up to 5 %.

Solar Photovoltaics in District Heating and Cooling Sector: An Overview

With the prevalent energy scenario and climate changes, decarbonising energy sector has become the need of the hour. An environmentally friendly way is the utilisation of solar energy, which mainly involves the deployment of photovoltaic (PV) panels and/or solar thermal collectors. Unlike electricity generation, the application of photovoltaics in the district heating & cooling (DHC) sector is relatively new. Also, this energy route is not fully explored by scientific community. This paper aims to provide an overview of the photovoltaic application in district heating & cooling sector. At first, the utilisation of solar energy in the DHC sector is briefly described. Then relevant literature in PVDHC is reviewed. It was understood that different topologies are in place for solar energy integration in the DHC system. These topologies vary in terms of the chosen technology, energy storage, system configuration (centralized/distributed) and components. It was found that the research database on the studied topic needs enhancement, with a special focus on PV cooling. From the literature survey, it is deduced that solar PV could play a significant role in future DHC systems due to the possible combination with other energy sources or electric grid or storage technology. Based on the SWOT analysis, it is concluded that there is an enormous opportunity for PV integration in the DHC sector. However, adequate techno-economic support is required to overcome threats and weaknesses. This study is expected to be beneficial to policymakers, researchers and other stakeholders in district energy market.

Carbon neutrality and renewable energy development in China

ABSTRACT Building a new type of power system with wind and solar as the dominant body of sources is expected to play the key role for China to achieve carbon neutrality. Transiting from the fossil fuel dominating power system to a renewable dominating system requires both the technology progress and the institutional changes. The total direct investment cost of China’s power system decarbonization is estimated to be about 67.6 trillion yuan, which consists of new wind and solar power capacity, energy storage facilities, and transmission lines. The electricity storage technology is the key factor to affect the transitional costs. Meanwhile, institutional changes are needed to adapt to the high penetration of wind and solar to cope with the new challenges the renewable brings, namely the flexibility, adequacy and affordability. China’s market-oriented reform should move to the direction of establishing a real unified national market system to achieve the integration of high percentage of renewables.

RELATIVE ASSESSMENT OF THE COST OF RESERVATION OF RENEWABLE ENERGY SOURCES

The generation of electricity by solar and wind power plants depends on natural conditions, and therefore there are problems with their participation in the process of balancing the modes of electric power systems (EPS). It is difficult for them to carry out the forecasted and approved hourly generation schedule for the next day with the specified accuracy. The UES is forced to keep a capacity reserve to compensate for deviations of renewable energy sources (EPS) from the projected generation schedule. Since these deviations can be both larger and smaller than the permissible ones, it is by this criterion that we can choose and form a means to balance the EPS regimes. The paper proposes a method for researching backup measures of renewable energy sources with unstable generation in EPS. The criterion of optimality for comparing RES reservation methods is their relative costs 
 Among the ways of reserving RES, system reserve is generally used (mainly the maneuverable capacities of thermal and hydroelectric power plants), but since it is not enough, it is suggested to use other means of reserving power available today: electrochemical electricity storage, hydrogen and biogas technologies.
 Mathematical models based on the theory of similarity and the criterion method have been developed to analyze the technical and economic efficiency of certain means of reservation. The criterion method is preferred due to the fact that, with minimal available initial information, it provides an opportunity to compare different methods of reserving RES generation and determine the optimal ones. The method makes it possible to assess their proportionality, as well as to determine the sensitivity of costs to the power of reservation methods.
 Criterion models have been formed that make it possible to build the dependence of the costs and reserve means of variable RES generation on the capacity of the reserve means.. Such dependencies make it possible to more reasonably choose certain reservation methods at the first stage in accordance with the characteristics and requirements of the UES. They can be clarified if the price indicators that are valid at the moment and for the near future are known.

SWHORD simulator: A platform to evaluate energy transition targets in future energy systems with increasing renewable generation, electric vehicles, storage technologies, and hydrogen systems

This paper presents the simulation platform SWHORD, specially designed for the analysis of future energy systems under energy transition targets. The model is implemented in GAMS as a cost minimization mixed integer programming problem of a hydro-thermal power system, which includes high penetration of non-dispatchable renewable generation, storage technologies, electric vehicles, and hydrogen systems. Simulations are performed on an hourly basis for one year of operation, enabling the evaluation of both short-term dynamics and the seasonal behaviour of the system and including the hourly power generation profile by technology, fuel and emission costs, CO2 emissions and storage levels, as well as the renewable curtailment needed to balance the system. The model was validated by backtesting with historical data of the Portuguese power system and, from a comprehensive statistical analysis of the dispatchable generation, it is concluded that the simulation results present a good fit with the real data. An illustrative use case is presented to evaluate the consistency of the Portuguese targets for 2030. Simulation results put in evidence the advantages of the SWHORD simulator to study the complex interactions among the new drivers of future energy systems, such as electric vehicles, storage technologies, and hydrogen systems.

Simulation and economic analysis of the high-temperature heat storage system of thermal power plants oriented to the smart grid

With the continuous increase of the grid-connected proportion of intermittent renewable energy, in order to ensure the reliability of smart grid operation, it is urgent to improve the operational flexibility of thermal power plants. Electric heat storage technology has broad prospects in terms of in-depth peak shaving of power grids, improving new energy utilization rates and improving the environment. It is an important means to promote electric energy substitution. In this study, the economics of technical application scenarios are compared and analyzed, the principle of solid heat storage technology is discussed, and its application in heating fields such as industrial steam, district heating, and deep peak regulation of congeneration units is expounded. The results indicate that in the scenario where the peak shaving subsidy and the heat storage duration are the same, as the unit output increases, the investment recovery period increases. Moreover, the results also indicate that in the 0.3 yuan/kW power market peaking subsidy scenario, only when the unit output is 0 and the heat storage time is greater than 8 h, the investment can be recovered in 5 years, while in the 0.7 yuan/kW power market peaking subsidy scenario, except for the scenario where the unit output is 40% and the heat storage time is 7 h, the investment cannot be recovered; in other scenarios, the investment can be recovered within 5 years.

Thermo-economic performance of a compressed CO2 energy storage system with a flexible gas holder

In recent years, engineers' eyes have been increasingly captured by the compressed CO2 energy storage since it is a competitive electricity storage technology equipped with massive renewable power plants. Nevertheless, how to design an effective system configuration, for instance the scenarios of storing CO2 in high and low pressures, vacillates to the left and right in the researchers. A CO2 energy storage cycle, configured by three section compression/expansion, two-tank heat storage, artificial tank for storing high pressure CO2 liquid and gas holder for storing ambient pressure CO2, is comprehensively examined in this paper. Both the thermodynamic and economic performances are considered. Results demonstrate that the round trip efficiency is capable of arriving at 71 % along with the levelized cost of electricity being 0.1252 $/kWh. Inspiringly, the system is operated with low pressures, charge pressure being 8 MPa and discharge pressure being 6 MPa. The turbomachineries are provided with the 68.18 % share of overall exergy destruction. The high pressure heater carries the largest exergy destruction among heat exchangers. By integrating with low grade waste heat of 39 °C, the efficiency can be further improved to 72.66 % with the levelized cost of electricity being 0.1242 $/kWh. Meanwhile, the discharge pressure should be raised to 6.58 MPa.

Batteries and beyond: Multi-vector energy storage as a tool to decarbonise energy services

With the 2015 Paris Agreement pursuing efforts to limit global temperature increase to below 2°C above pre-industrial levels and the “energy trilemma” goals of energy security, energy equity and environmental sustainability, decarbonisation remains a priority across all of the United Kingdom (United Kingdom) energy system, not just electricity. Electricity and thermal energy storage technologies can offer a host of benefits across the energy value chain through the abilityS to capture, store and then release electricity or thermal energy over a period of time. These benefits include helping capture the full potential of renewable generation and providing services such as frequency response and reserve to Great Britain’s (GB) electricity system. In addition, with the aforementioned climate targets in mind, energy storage can also play a role in facilitating the decarbonisation of other activities and sectors. Here we delve deeper into how energy storage technologies can contribute to both energy sector transformation and more broadly, decarbonisation. Furthermore, we discuss the importance of ensuring a technology-agnostic approach to the development of policy and regulation with relevance to energy storage. This ensures that storage technologies with significant potential to contribute to the ‘energy trilemma’ goals are not precluded from entering the market due to unfavourable policy and regulatory frameworks.

Prospects of electricity storage

With the expansion of renewables in the electricity markets, research on electricity storage economics is needed for a better understanding of the utilization of these systems and for improving the performance of intermittent variable generation. Collected up-to-date research of electricity storage systems published in a wide range of articles with high impact factors gives a comprehensive review of the current studies regarding all relevant parameters for storage utilization in the electricity markets. Valuable research of technical characteristics from the literature is broadened with the electricity storage analyses from an economic point-of-view. Analysis of selected technologies, considering different perspectives such as their profitability, technical maturity, and environmental aspect, is a valuable addition to the previous research on electricity storage systems. Comparing conducted analysis with the selected literature, electricity storage technologies are analyzed concerning their viability in the electricity markets. Given the current outlook of the electricity market, the main problems for storage's wider integration are still energy storage costs. These can be overcome with different applications of energy storage systems, integration of new market players, or a combination of storage technologies along with the implementation of new energy policies for storage.

Building-integrated photovoltaics (BIPV) combined with hydrogen-based electricity storage system at building-scale towards carbon neutrality

Electricity storage technologies in buildings are evolving, mainly to reduce their environmental impact and to improve self-sufficiency of buildings that produce their own energy through Building-Integrated Photovoltaics (BIPV) installations. To maximize self-consumption - minimizing the import of grid electricity - photovoltaic (PV) systems can be coupled with a hydrogen storage system converting the electricity to hydrogen by electrolysis during the summer season - when the on-site production is higher - and employing it during the winter season with fuel cells. This study focuses on the sizing constraints of solar hydrogen systems at building-scale using an innovative research-centre that will be built in Fribourg (Switzerland). It presents four stories and a mix-usage (office spaces and research facilities areas) and multi-oriented PV installation in order to produce enough electricity to achieve at least 50 % of electricity self-sufficiency ratio. Using the PV production, this study aims to optimise the sizing of a hydrogen storage system allowing to reach the required self-sufficiency ratio with the lowest environmental impact possible. Ultimately, the global energy and financial efficiency of the system will be analysed.