Energy Storage Projects Research Articles

An Internal Type-2 Trapezoidal Fuzzy Sets-PROMETHEE-II based Investment Decision Framework of Compressed Air Energy Storage Project in China under the Perspective of Different Investors

• Establish a novel investment decision-making framework of the promising compressed air energy storage in China • Construct a comprehensive investment decision-making criteria system of CAES project • Build a scenario analysis model based on different investor preferences • A serious of sensitive investment criteria are identified for improving the investment decision making of CAES project. Along with the huge demand for volatility remedies of renewable energy, the construction of compressed air energy storage plant has been paid great attention around the world since it is economical to help flatten the intermittency, less geography restriction and little environment impact. To select the optimal compressed air energy storage project with massive difficulties in different preference of investors to energy development directions, uncertainties of decision-making environment and complex and various attributes of the evaluation object, an investment decision making framework is proposed in this paper from the perspective of four different types of investors based on internal type-2 trapezoidal fuzzy sets and PROMETHEE-II model. To validate the effectiveness of the established investment decision making framework, a case study in China is conducted. Result shows that different types of investors will have different optimal investment decision making results, and the investment selection results between the central government and local government, enterprises and individuals have a certain degree of consistency. Meanwhile, the stability and robustness as well as the superiority of the result and the proposed framework are confirmed by the sensitive and comparative analysis. This research possesses practical application value for investors or project managers in project investment choices.

Technoeconomic model of second-life batteries for utility-scale solar considering calendar and cycle aging

The rapid proliferation of electric vehicles is creating a fleet of millions of lithium-ion batteries that will be deemed unsuitable for the transportation industry once they reach 80% of their original capacity. The repurposing and deployment of these batteries as stationary energy storage provides an opportunity to reduce the cost of solar-plus-storage systems, if the economics can be proven. We present a techno-economic model of a solar-plus-second-life energy storage project in California, including a data-based model of lithium nickel manganese cobalt oxide battery degradation, to predict its capacity fade over time, and compare it to a project that uses a new lithium-ion battery. By setting certain control policy limits, to minimize cycle aging, we show that a system with state-of-charge limits in a 65–15% range, extends the project life to over 16 years, assuming a battery reaches its end-of-life at 60% of its original capacity. Under these conditions, a second-life project is more economically favorable than a project that uses a new battery and 85–20% state-of-charge limits, for second-life battery costs that are <80% of the new battery. The same system reaches break-even and profitability for second-life battery costs that are <60% of the new battery. Our model shows that using current benchmarked data for the capital and operations and maintenance costs of solar-plus-storage systems, and a semi-empirical data-based degradation model, it is possible for electric vehicle manufacturers to sell second-life batteries for <60% of their original price to developers of profitable solar-plus-storage projects.

Technologies of Engagement: How Battery Storage Technologies Shape Householder Participation in Energy Transitions

The transition to a low-carbon energy system goes along with changing roles for citizens in energy production and consumption. In this paper we focus on how residential energy storage technologies can enable householders to contribute to the energy transition. Drawing on literature that understands energy systems as sociotechnical configurations and the theory of ‘material participation’, we examine how the introduction of home batteries affords new roles and energy practices for householders. We present qualitative findings from interviews with householders and other key stakeholders engaged in using or implementing battery storage at household and community level. Our results point to five emerging storage modes in which householders can play a role: individual energy autonomy; local energy community; smart grid integration; virtual energy community; and electricity market integration. We argue that for householders, these storage modes facilitate new energy practices such as providing grid services, trading, self-consumption, and sharing of energy. Several of the storage modes enable the formation of prosumer collectives and change relationships with other actors in the energy system. We conclude by discussing how householders also face new dependencies on information technologies and intermediary actors to organize the multi-directional energy flows which battery systems unleash. With energy storage projects currently being provider-driven, we argue that more space should be given to experimentation with (mixed modes of) energy storage that both empower householders and communities in the pursuit of their own sustainability aspirations and serve the needs of emerging renewable energy-based energy systems.

Storage Gravitational Energy for Small Scale Industrial and Residential Applications

Photovoltaic cells produce electric energy in a short interval during a period of low demand and show high levels of intermittency. One of the well-known solutions is to store the energy and convert it into a more stable form, to transform again into electricity during periods of high demand, in which the energy has a higher value. This process provides economic viability for most energy-storage projects, even for the least efficient and most common, such as batteries. Therefore, this paper aims to propose a storage system that operates with gravitational potential energy, considering a small-scale use. The development of this methodology presents the mathematical modeling of the system and compares the main characteristics with other systems. The dimensions of the considered system are 12-m shaft, 5-m piston height, and 4 m of diameter; it presented an energy storage of 11 kWh. Also, it has an efficiency of about 90%, a lifetime of 50 years, and higher storage densities compared to other systems.

Assessment of economic benefits of battery energy storage application for the PV‐equipped households in Finland

Significant growth in residential solar photovoltaic (PV) installations and the ongoing decline in battery costs have increased interest in household solar battery energy storage projects in Finland in recent years. Among various potential applications, considerable attention is drawn to the use of the battery energy storage system (BESS) for the purpose of the households’ self-consumption enhancement. This study presents the results of a techno-economic study of the LiFePO4-based battery storage added to residential roof-top PV installations in Finland to maximise self-utilisation of on-site solar energy generation. Using a comprehensive DC model of BESS, the battery charge and discharge levels under the typical household load and PV production conditions are simulated. The estimates of the average retail electricity prices are used to assess the value that the customer-sited solar battery storage can provide to the household end-users in Finland. The economic attractiveness of the battery storage projects is evaluated considering the present and forecasted BESS costs and the electricity tariff levels in Finland and the conditions for profitable operation of the solar energy storage systems are determined.

The economy of wind-integrated-energy-storage projects in China's upcoming power market: A real options approach

Renewable energy is growing quickly in China, but curtailment is serious due to insufficient system flexibility. Integrated energy storage system is one of effective approaches to improve production profile and alleviate curtailment. In this study, we evaluate the value of wind-integrated energy storage (WIES) projects by combining methods of real options and net present value. We draw appropriate investment timing based on the dynamics of storage cost and degree of marketization. The medium-marketization or even high-marketization scenarios examined in this study will appear in five years. The results indicate that with a 10% learning rate of energy storage cost, the WIES project will be commercially justified in one year under high-level marketization scenario and in 3 years under medium-level marketization. Finally, we conclude with policy implications on market integration of renewable energy in China.

Performance evaluation of an industrial borehole thermal energy storage (BTES) project – Experiences from the first seven years of operation

Borehole thermal energy storage (BTES) is a technology which allows for both seasonal and short-to-medium-term storage of thermal energy and which can be used for both heating and cooling. This makes BTES of special interest to many industries. However, post-implementation evaluations of large-scale industrial BTES are scarce. The BTES at Xylem's production plant in Emmaboda, Sweden is one of the world's largest BTES systems for storage of industrial excess heat. In this paper, the BTES at Emmaboda was evaluated with respect to how it was integrated and how it has performed during its first seven years of operation. The BTES consists of 140 boreholes, 150 m deep, and heat for storage is mainly recovered from two high-temperature ovens and the foundry ventilation air. So far, the highest heat extraction and BTES efficiency (19%) took place in the storage system's sixth full year of operation, when roughly 2200 MWh and 400 MWh were injected into and extracted from the storage respectively. One main reason extraction is not higher is that the quantities and/or the quality of the excess heat for storage are lower than estimated, thus hindering the storage from reaching the necessary temperatures for heat extraction.

(Invited) 100MW-class vanadium flow battery projects in different applications in China

Vanadium flow battery (hereafter referred as VFB) is one of the most suitable energy storage systems (hereafter referred as ESS) for grid-connected renewable power. And the inherent capitalization potential will improve its commercialization further in the coming future as well. However, comparing to other popular energy storage technology, VRB technology is still lack of experience on large-scale application in different situation. As the Guideline to Promote Energy Storage System Technology and Industrial Development (the Guideline) issued by five ministries of China (Reform Commission, Ministry of Finance, Ministry of Science and Technology, Ministry of Industry and Information Technology, National Energy Administration) in October 2017 mentioned clearly one of the key commercialized technology should be 100MW VRB-ESS power station, there is several important large-scale flow battery projects promoted in China in 2018, such as 100MW/500MWh peak plant in Hubei, 200MW / 800MWh renewables integration in Liaoning, 200MW / 1,000MWh offshore wind integration in Jiangsu and renewable power integration in Qinghai. Some of the confirmed projects is listed in the following figure. Figure 1. China’s vanadium flow battery energy storage projects development plan Several provinces in south coastal area of China, such as Jiangsu, ESS is for peak shifting and arbitrage application as the urgent need of flexible/ Independent peak plants to support the summit power demand in summer. The 100MW/500MWh peak plant in Hubei is mostly to support power requirement of industrial parks. While Qinghai province is the most active place for renewable energy developing and requires large-scale ESS to support grid connection. VRB Energy has got involved closely in most of these projects, and looking forward to share experience and future prospects accordingly. VRB Energy Operations (Beijing) Co. Ltd., used to known as Pu Neng, the supplier of the 2MW/8MWh VRB-ESS State Grid demonstration site in Zhangbei, Zhangjiakou, China, and 3MW/12MWh VRB-ESS in Zaoyang, Hubei, China. The 3MW/12MWh VRB-ESS in Zaoyang has commissioned in Oct 2018, and provided a technical foundation for the coming 100MW/500MWh project in Hubei. VRB Energy has followed up the 200MW / 1,000MWh offshore wind integration in Jiangsu and wind integration projects in Qinghai closely. Some of the projects are most likely to start construction in 2019. Additionally, National Development and Reform Commission, state grid, and National Energy Committee issued the ESS price policy to support the ESS development in China. The policy includes increase the power price gap between peak time and off peak time, tax refund, and reward to the ESS project which can provide the good service to state grid, etc. With economic support and practical large-scale projects, the Chinese power market is expected to form a completed market mechanism in the near future.

(Invited) 100MW Class Vanadium Flow Battery Project Plan in China

With the rapid development of modern society and industries, the resource depletion and environmental problems caused by the large amount of energy consumption are imminent.Although new energy is a solution to power shortage, the discontinuity and instability causes serious energy waste. Large-scale energy storage technology has received remarkable achievements in solve energy waste problems, which has attracted the attention of various countries. Vanadium redox flow battery is considered as an ideal large-scale energy storage technology because of its long cycle life, fast reaction, high conversion efficiency and reliable safety. This paper takes China, one of the major new energy markets, as an example. It introduces the plan of China on large-scale 100MW-class vanadium redox flow battery energy storage projects in the coming future, and specifies on Zaoyang 3MW/12WMh energy storage project, which is the pioneer project of 100MW-class energy storage project in Wuhan, Hubei Province, China..

A Review on Public Understanding of Carbon Dioxide Capture and Storage (CCS) in South Korea

Since the Paris Agreement, member countries have set national goals clearly stated in the “Intended Nationally Determined Contributions” (INDC) to reduce the intended amount of carbon dioxide. In many other countries, the government has invested in national R&D to promote cleaner energy and Carbon Capture and Storage (CCS) projects that is considered as one of the most pragmatic means to achieve the set mitigation target in a national scale. In some country, the control and management of CO2 has been implemented in new technical systems called CO2 smart grids. However, along with continual CCS R&D, laws and regulatory interventions supporting its technical pillars should mutually encompass its development. Without public understanding, technological development cannot be fully implemented by the involved public and private entities permitting to attain the set mitigation targets. In previous research, only few studies on public understanding have linked its policies to the actual valid legislation. This article therefore aims to review the overall public understanding conditions on CCS in Korea and to systematically outline public understanding in actual Acts as well as in the Draft of Korean integrated CCS Act. Finally, this research tried to imply regulatory intervention guidelines on public understanding of CCS along with possible improvement for the next revision of the Korean CCS Act.

The case for energy storage installations at high rate EV chargers to enable solar energy integration in the UK – An optimised approach

Abstract Solar energy installations face ever more constrained networks, hindering easy and effective installation of low carbon technologies onto the grid in the UK. However, they are critical for the advancement to a low carbon society. There is a need, therefore, to provide means which enable easier installation of solar energy. By co-locating solar energy with high rate electric vehicle chargers (HREVCs) it is proposed that the grid can be by-passed, thus providing low carbon energy directly to EVs. For an effective system an off-vehicle energy store (OVES), which enables matching of supply with demand, must be included. This paper introduces a model of an HREVC with integrated OVES and optimises the design variables for maximum profit and minimum energy exchanged with the grid. By addressing these issues, the author's model will help inform EV infrastructure designers and policy makers. It is found that the addition of an OVES increases the profit for systems installed where the grid connection cost is high. Indeed, the value of this improvement provides a more profitable business model for energy storage than other energy storage project revenue streams currently successful in the UK (0.5–3 £ m/MWh/year compared to 50,000–200,000 £ k/MWh/year).

Assessing energy storage technology options using a multi-criteria decision analysis-based framework

With the growing adoption of intermittent renewable energy generation the role for energy storage to provide a number of service needs is being increasingly recognised. However, ‘energy storage’ encompasses a family of technologies, each with its own set of performance, cost and physical characteristics, at different stages of development. At the same time, each energy system – however defined – has specific needs; and energy systems are themselves part of a wider socio-technical system which has aims beyond the confines of the energy ‘trilemma’. As energy storage technologies develop, funding is becoming available to demonstrate their application in realistic environments. However, with multiple technical and non-technical factors to consider, it is challenging for many decision makers who often have limited expertise and resources to select which projects to support.In this paper we first describe a novel framework for assessing the wider benefits that could come from deploying energy storage using Multi-Attribute Value Theory (MAVT), a form of Multi-Criteria Decision Analysis. We then use the framework to assess six potential energy storage projects through a combination of technical analysis and stakeholder input in the county of Cornwall in the UK: a region that has good solar and wind resource with relatively low demand and constrained network infrastructure. The projects assessed were: power to gas, a distributed battery system, battery storage integrated with solar PV and demand from Cornwall Airport Newquay, liquid air energy storage, battery storage integrated with wave energy, and thermal energy storage at a new residential development.We conclude that MAVT can provide a straightforward and user-friendly approach, which can be easily used by decision makers for assessing energy storage projects across a range of criteria and promoting engagement with stakeholders. This approach also allows the subjectivity of decision-making, a potential limitation, to be explored through a sensitivity analysis. The use of MAVT can lead to important insights for the development of energy systems, which in this study included the importance of local priorities to decision-making.In this case, battery storage with PV and demand from Cornwall Airport Newquay was the top-ranking project, performing well across a range of attributes including the maturity of the technology, its ability to defer grid upgrades and economic viability.

A social cost benefit analysis of grid-scale electrical energy storage projects: A case study

This study explores and quantifies the social costs and benefits of grid-scale electrical energy storage (EES) projects in Great Britain. The case study for this paper is the Smarter Network Storage project, a 6 MW/10 MWh lithium battery placed at the Leighton Buzzard Primary substation to meet growing local peak demand requirements. This study analyses both the locational and system-wide benefits to grid-scale EES, determines the realistic combination of those social benefits, and juxtaposes them against the social costs across the useful lifecycle of the battery to determine the techno-economic performance. Risk and uncertainty from the benefit streams, cost elements, battery lifespan, and discount rate are incorporated into a Monte Carlo simulation. Using this framework, society can be guided to cost-effectively invest in EES as a grid modernization asset to facilitate the transition to a reliable, affordable, and clean power system.

Thermal Performance and Operation of a Solar Tubular Receiver With CO2 as the Heat Transfer Fluid

A high-temperature, high-pressure solar receiver was designed as part of the advanced thermal energy storage project carried out in collaboration with Abengoa Solar NT at CSIRO Energy Centre in Newcastle, Australia, with support through the Australian Renewable Energy Agency (ARENA). The cavity-type receiver with tubular absorbers was successfully installed and commissioned, using concentrated solar energy to raise the temperature of CO2 gas to 750 °C at 700 kPa in a pressurized, closed loop system. Stand-alone solar receiver tests were carried out to investigate the thermal characteristics of the 250 kWt solar receiver. The on-sun full-load test successfully achieved an outlet gas temperature of 750 °C while operating below the maximum allowable tube temperature limit (1050 °C) and with a maximum pressure drop of 22 kPa. The corresponding estimated receiver thermal efficiency values at full flow rate were 75% estimated based on measured receiver temperatures and heat losses calculations for both single aim-point and multiple aim-point heliostat control strategies. The use of a quartz glass window affixed to the receiver cavity aperture was tried as a means for improving the receiver efficiency by reducing convective heat losses from the receiver aperture. However, while it did appear to significantly reduce convective losses, a more effective metal support frame design is necessary to avoid damage to the window caused by stresses introduced as a result of distortion of the supports due to heating by the spillage of rays from the heliostat field.

Stochastic valuation of energy storage in wholesale power markets

Energy storage systems are well poised to mitigate uncertainties of renewable generation outputs. Grid-scale energy storage projects are major investments which call for rigorous valuation and risk analysis. This paper provides a stochastic energy storage valuation framework in wholesale power markets which considers all key revenue streams simultaneously. As part of this framework, an operational optimization model is developed to determine the energy storage system's optimal dispatch sequences. A future curve model is built to capture the volatilities of electricity prices. In addition, a frequency regulation service price forecasting model is developed. Simulation results with a realistic battery storage system reveal that the majority of the market revenues comes from frequency regulation services. Simulation results also show that both round-trip efficiency and power-to-energy ratio are crucial to the cost effectiveness of energy storage systems.

Profitability, risk, and financial modeling of energy storage in residential and large scale applications

The increasing share of renewable energy plants in the power industry portfolio is causing grid instability issues. Energy storage technologies have the ability to revolutionize the way in which the electrical grid is operated. The incorporation of energy storage systems in the grid help reduce this instability by shifting power produced during low energy consumption to peak demand hours and hence balancing energy generation with demand. However, the deployment of some energy storage systems will remain limited until their economic profitability is proven. In this paper, a cost-benefit analysis is performed to determine the economic viability of energy storage used in residential and large scale applications. Revenues from energy arbitrage were identified using the proposed models to get a better view on the profitability of the storage system. Moreover, the feasibility of energy storage projects relies on the readiness of investors to invest in the project. This willingness is significantly affected by several factors such as the risk of the innovative storage concept. To analyse the profitability risk associated with such energy project, a sensitivity analysis is performed in this study.

Hydrogenics for first renewable hydrogen-based energy storage, power plant in SE Asia

Canadian-based Hydrogenics, along with Phraram 2 Civil Engineering Co Ltd (PCE) in Bangkok, has been awarded the Lam Ta Khong Wind Hydrogen Hybrid Project by the Electricity Generation Authority of Thailand (EGAT). This will be the first MW-scale energy storage project in southeast Asia.

Heat tracer test in an alluvial aquifer: Field experiment and inverse modelling

Using heat as an active tracer for aquifer characterization is a topic of increasing interest. In this study, we investigate the potential of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in an injection well and monitoring the evolution of groundwater temperature and tracer concentration in the pumping well and in measurement intervals. To get insights in the 3D characteristics of the heat transport mechanisms, temperature data from a large number of observation wells closely spaced along three transects were used.Temperature breakthrough curves in observation wells are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume is explained by the groundwater flow gradient on the site and heterogeneities in the hydraulic conductivity field. Moreover, due to high injection temperatures during the field experiment a temperature-induced fluid density effect on heat transport occurred. By using a flow and heat transport numerical model with variable density coupled with a pilot point approach for inversion of the hydraulic conductivity field, the main preferential flow paths were delineated. The successful application of a field heat tracer test at this site suggests that heat tracer tests is a promising approach to image hydraulic conductivity field. This methodology could be applied in aquifer thermal energy storage (ATES) projects for assessing future efficiency that is strongly linked to the hydraulic conductivity variability in the considered aquifer.

Semi-Empirical Modeling of Capacity Fade: A Practical Approach for Battery Pack Manufacturers

Lithium ion batteries are rapidly increasing in usage for stationary energy storage projects, and market forecasts predict continued accelerating growth in these fields. For industrial and grid applications, customer requirements and return-on-investment goals necessitate long system lifetime (10-15 years) and a guaranteed number of cycles or total energy throughput. Battery pack manufacturers must design their systems to reliably meet these life requirements while minimizing cost. However, for most pack assemblers the prerequisite information on cell ageing is neither available from the cell supplier nor easily obtainable via testing. Given the rapid development of new materials and cell model lines, it becomes an enormous task for pack manufacturers to conduct comprehensive in-house testing of all candidate cells. In order to make industrial lithium ion batteries feasible and competitive, system manufacturers must reduce costs by leveraging the newest state-of-the-art cell technology and independently ensuring it fulfills the lifetime requirements. This latter task must be accomplished using a manageable scope of cell lifetime testing that keeps up with the rapid pace of new cell development (12 months). Appropriate modeling can be used to extrapolate testing results to the projected lifetime target, but such models must be reliably accurate so as to reduce the high level of uncertainty and risk associated with constructing systems using newly released cells. Toward these ends, we have developed and implemented a semi-empirical modeling approach [1, 2] that is practical and effective for a small pack manufacturing company. The model incorporates a limited set of cell degradation mechanisms to predict capacity fade. Based on a specific product application, grid-tied frequency regulation, an experimental matrix was designed to elucidate the effects of temperature, depth-of-discharge (DOD), time, and energy throughput on calendar and cycle ageing. The focus on one usage profile helped to reduce the number of pertinent independent variables and required tests. Cell storage testing was performed at 25, 35, 45, and 55°C, and cycle tests were conducted with DOD of 10, 20, 40, 60, and 80%. The semi-empirical model was constructed using a mathematical framework reflective of the physics-based ageing mechanisms for SEI growth [3] and particle fracture [4, 5], fitted to the experimental dataset. Good agreement between the model predictions and test results for capacity fade are shown for two different state-of-the-art 18650 cell models. This semi-empirical model demonstrates how a pack manufacturer can successfully assess the lifetime performance of new cell technologies for applications with strict lifetime requirements, while addressing risk and supporting product warranty. The physical basis of the modeling approach yields reliable predictions, and its simple formulation reduces the required testing and timeline for completion. When used on a number of newly released cells, this model approach becomes a useful tool to guide cell selection, battery system oversizing, and thermal management requirements [6], which can all lead to reductions in battery cost.

Legal implications for renewable energy storage projects

Lee Gordon and Michael Bennett highlight some of the key legal issues relating to planning and construction work for renewable energy storage developments.