Innovative configuration of a hybrid nuclear-parabolic trough solar power plant

This paper proposes a combination of a nuclear and a concentrated solar power (CSP) plant. Most of today’s operating nuclear reactor systems are producing saturated steam at relatively low pressure. This, in turn, limits their thermodynamic efficiency. Superheating of nuclear steam with solar thermal energy has the potential to overcome this drawback. An innovative configuration of a hybrid nuclear-CSP plant is assembled and simulated. It brings together a small pressurised water reactor and a parabolic trough solar field. The solar heat is transferred to nuclear steam to raise its temperature. Continuous superheating is provided through molten salts-based thermal energy storage (TES). The results from design point calculations show that solar superheating has the potential to increase nuclear plant electric efficiency significantly. Solar heat to electricity conversion efficiency defined as the ratio of extra generated power to collected solar energy reaches unprecedented rates of 52%. An off-design model was used to simulate 24-h operation for one year by simulating 8760 cases. Due to TES non-stop operation is manageable.     

Analysis of the problem of optimal placement and capacity of the hydrogen energy storage system in the power system

Nowadays the trend of increasing the generation units based on renewable energy sources in the electric power system can be observed. Obviously, this is due to the intensifying level of consumer load and demand for electricity. However, renewable generation is characterized by intermittent energy production, which can cause and potential imbalance between generation and demand, especially during off-peak periods. Therefore, in order to ensure a reliable power supply to consumers, it is necessary to use a maneuverable reserve of capacity, such as energy storage systems, in conjunction with the renewable energy source unit. Over the past 10 years, the energy storage market has grown by almost 50%: the installed capacity of energy storage system in the world is about 5 GW. Analysis of the literature on the subject determines the need to study the impact of these devices on the parameters of electric power systems and one of the primary tasks is to determine the optimal location and capacity of energy storage system in the power system. This paper presents the result of solving the task of determining the optimal parameters of a hydrogen energy storage system using the particle swarm optimization method for example a test scheme radial distribution system – 33 bus IEEE. The choice of the type of energy storage is based on such advantages of a hydrogen energy storage system as environmental friendliness, high energy capacity and the ability to store electricity for a long period of time. In addition, compared to lithium-ion batteries, hydrogen energy storage systems have a long life time of about 25 years, during this period of time there is no degradation and significant deterioration of its properties. All these advantages of hydrogen as an energy carrier allow to take into account not only the criterion of total value of active power losses and its maximum reduction respectively, but the possibility and economic efficiency of partial use of the stored hydrogen for other needs when determining the optimal scenario of their operation in the process of discharge.     

Operation principle and applications of multiterminalsuperconductive magnetic energy storage systems

The basic operation principle of a multiterminal superconductive magnetic energy storage (MSMES) system is introduced. The motivation for developing the MSMES systems is to combine and maximize the flexibility benefits provided by energy storage and the controllability benefits provided by power electronic systems. A MSMES system can be used simultaneously as an energy storage device and a power flow control device. This attribute enables MSMES systems to perform some unique functions in electric power systems. Potential applications of MSMES systems and their impact on solving the problems faced by power systems today are discussed     

Humankind’s detour toward sustainability: past,present, and future of renewable energies and electric power generation

Renewable energies have been the primary energy source in the history of the human race. During the last 200 years, industrialized countries have shifted their energy consumption toward fossil fuels. Contemporary electric power generation is based on non-renewable resources such as oil, coal, and nuclear power. New efficient and cost-effective small-scale renewable energy generation options are commercially available today. Market distortions are to be overcome in order to make renewable energies cost-competitive in today’s economic environment. Social, environmental and also economic reasons will reverse the worldwide primary energy use back to renewables and thus reapproach a sustainable economic system based on traditional and new high-tech technologies.     

Independent thermal storage power station with molten salt:Technology and evaluation

储能电站可解决可再生能源间歇性和不稳定性的问题,满足常规电力系统和区域能源系统效率,安全性和经济性的迫切需要.本文提出了一种新的蓄热电站技术----独立熔盐蓄热电站,进行了独立熔盐蓄热电站原理的介绍,概念设计和技术经济评价.结果表明:独立熔盐蓄热电站初期投资很低,仅为6152.88元/kW,投资回收期短,在3年以内.独立熔盐蓄热电站占地面积小,可建在城市中实现热电联供,总能效率可由单纯发电的30%提高到80%以上.     

Superconducting magnetic energy storage

Superconducting magnetic energy storage (SMES) is an energy storage technology that stores energy in the form of DC electricity that is the source of a DC magnetic field. The conductor for carrying the current operates at cryogenic temperatures where it is a superconductor and thus has virtually no resistive losses as it produces the magnetic field. The overall technology of cryogenics and superconductivity today is such that the components of a SMES device are defined and can be constructed. The integrated unit appears to be feasible for some utility applications at a cost that is competitive with other technologies. SMES is the only technology based on superconductivity that is applicable to the electric utilities and is commercially available today. In addition to today's power quality application, the historical development of SMES starting with the concept of very large plants that would store hundreds of megawatt hours of energy and were intended for diurnal load leveling are described.     

Safe and Secure

This paper focuses on the issues critical to the operation of commercial nuclear power electric generating plants. These issues include safe, secure long-term plant operations, plant physical security, radioactive waste management, and environmental impact. Few energy choices can compete with the environmental benefits of nuclear power. By capturing and sequestering waste products during the entire fuel cycle, nuclear power is one of the cleanest baseload energy sources available. Long-term storage of used fuel is technically feasible in both aboveground storage containers and in underground geologic formations. Continued research into new nuclear reactors is expected to allow for almost complete consumption of the available unused fuel in high level waste     

Energy analysis of a power generating system

The application of energy analysis to nuclear power has provoked considerable controversy about both methodology and conclusions. This paper looks at the results of a UKAEA developed computer programme applied to a variety of nuclear scenarios. It concludes that energy analysis can add to understanding of energy problems but that the results can be misleading if applied to a single resource like fossil fuel. Any meaningful investment in nuclear power is not likely to repay its investment energy for at least four years after the first station is commissioned.     

Study on integrated development and hybrid operation mode of nuclear power plant and pumped-storage power station

The nuclear power plant is suitable for base-load operation, while the pumped-storage unit mainly gives play to capacity benefit in the electric power system; hence, the integrated development and hybrid operation mode of the two can better meet the needs of the electric power system. This article first presents an analysis of the necessity and superiority of such mode, then explains its meaning and analyzes the working routes. Finally, it proposes the business modes as follows: low price pumping water electricity plus nuclear power in the near term; nuclear power shifted to pumped storage power participating in market competition in the middle term; and, in the long term, nuclear power shifted to pumped storage power as primary and serving as an electric power system when needed.     

Proposal of utilization of nuclear spent fuels for gamma cells

Large amounts of nuclear spent fuel are generated in nuclear power plants every year and stored in fuel storage facilities for 20–30 years until reprocessing. However, the spent fuel still has residual energies, such as high-temperature heat energy and high-intensity gamma radioactivity. We have examined the characteristics of solar cells exposed to gamma radiation for the development of gamma cells utilizing nuclear spent fuel. We used a highly intense ⁶⁰Co gamma source as a suitable substitute for spent fuel due to safety concerns and convenience. Two representative types of solar cells, amorphous and crystalline cells, were examined and the current and voltage generated by each type were measured. In general, solar cells are largely insensitive to gamma radiation because the radiation passes through solar cells without imparting all of its energy. In order to enhance the sensitivity to radiation, the solar cells were coupled to CsI(Tl), NaI(Tl) and plastic scintillators. We confirmed the following characteristics: (1) amorphous solar cells coupled to a CsI(Tl) scintillator are able to generate a large amount of electric power, compared to crystal-type solar cells, (2) amorphous cells exhibit a good linear response to high-intensity gamma radiation and generate electric power almost in proportion to the volume of the scintillator used, (3) the generated electric power is independent of the incident angle of the gamma rays and the amount of power is determined only by the volume of the scintillator used. The electric power generated by a single solar cell is very small, but a large amount of electric power can be obtained by arranging many solar cells in stacks and combining their induced current or voltage and by operating the cells all day, as they are not affected by weather conditions. We concluded that gamma cells utilizing the gamma radiation of nuclear spent fuel can be expected to be useful for electric power generation in the near future.     

Overview of current and future energy storage technologies for electric power applications

In today's world, there is a continuous global need for more energy which, at the same time, has to be cleaner than the energy produced from the traditional generation technologies. This need has facilitated the increasing penetration of distributed generation (DG) technologies and primarily of renewable energy sources (RES). The extensive use of such energy sources in today's electricity networks can indisputably minimize the threat of global warming and climate change. However, the power output of these energy sources is not as reliable and as easy to adjust to changing demand cycles as the output from the traditional power sources. This disadvantage can only be effectively overcome by the storing of the excess power produced by DG-RES. Therefore, in order for these new sources to become completely reliable as primary sources of energy, energy storage is a crucial factor. In this work, an overview of the current and future energy storage technologies used for electric power applications is carried out. Most of the technologies are in use today while others are still under intensive research and development. A comparison between the various technologies is presented in terms of the most important technological characteristics of each technology. The comparison shows that each storage technology is different in terms of its ideal network application environment and energy storage scale. This means that in order to achieve optimum results, the unique network environment and the specifications of the storage device have to be studied thoroughly, before a decision for the ideal storage technology to be selected is taken.     

加速发展核电——中国能源结构调整的必由之路

论述了中国能源的发展战略和核电的重要地位。虽然不是新命题,但本文采用了界限分析等新概念,得出了更有说服力的结论:2035年左右核电在中国电力结构中的容量比率最少应达18%,核电必须加速发展。分析了发达国家高速发展核电的成功经验和近几年来中国火电飞速发展,指出在中国加速发展核电的时机已经成熟。只要统一认识,科学规划,重视核电的自主化、国产化以及必要的体制改革,实现本文所预期的目标不仅非常必要,而且一定可能。     

The energy storage mathematical models for simulation and comprehensive analysis of power system dynamics: A review. Part i

Energy storage systems are increasingly used as part of electric power systems to solve various problems of power supply reliability. With increasing power of the energy storage systems and the share of their use in electric power systems, their influence on operation modes and transient processes becomes significant. In this case, there is a need to take into account their properties in mathematical models of real dimension power systems in the study of various operation modes, design, etc. In this article the main types of energy storage devices, as well as the fields and applications of their use in electric power systems are considered. The principles of realization of detailed mathematical models, principles of their control systems are described for the presented types of energy storage systems. The article is an overview and can help in choosing a mathematical model of energy storage system to solve the necessary tasks in the mathematical modeling of storage systems in electric power systems.Information is presented on large hydrogen energy storage units for use in the power system.     

The Transformation of the Nuclear Power Industry

During the 1980s and early 1990s, the nuclear power generation industry in the US was viewed by the public as a dying industry owing mainly to concerns about the safety of the nuclear units, the storage of spent nuclear fuel, transportation of nuclear materials to central locations, and the general security of the nuclear facilities. Since then, the industry has transformed itself from one perceived as a dangerous, expensive technology to that of a reliable electrical power source. It is now viewed as a positive source of power from a global warming perspective. Aggressive industry initiatives to improve plant operation and maintenance have alleviated the public fear of nuclear technology. With the public unrest quieted and the cost of non-nuclear generation on the rise, the promise of nuclear power as a safe and reliable energy source may now be realized     

Hydrogen electrical energy storage by high-temperature steam electrolysis for next-millennium energy security

It would be highly significant if energy, which is intimately related with the continued existence of human beings, were sustainable on the basis of the present resources for the next thousand years. The effectiveness of hydrogen for energy storage by high-temperature steam electrolysis is clarified by showing its features with reference to solar energy and nuclear energy for power storage as examples. It is also shown that use of hydrogen for energy storage would be effective for widespread utilization of current energy resources, such as renewables and nuclear energy, over the next millennium.     

Hidden biases in Australian energy policy

The challenges in developing technology for the capture and storage of CO₂ from coal, oil and gas power generation, as well as those associated with the storage of nuclear waste, are widely regarded as solvable. According to proponents of clean coal, oil and gas technologies, as well as the proponents of nuclear technology, it is only a matter of time and resources to find a solution to their waste problems. Similarly, the Australian Government argues that our main efforts need to be concentrated on clean coal technologies, as well as considering the nuclear option. However, when it comes to the challenges associated with renewable energy technologies, like intermittency of wind generated grid power, storage of electricity from renewable energy and so on, there seems to be an attitude amongst Australian energy planners that these challenges represent insurmountable technical and financial problems, and will, at least in the short to medium term, prevent them from becoming a viable alternative to coal, oil, gas and uranium based energy technologies.     

Life-cycle energy efficiency estimation of large-scale ammonia fuel energy storage system

本文讨论了氨作为燃料使用会具备与传统化石燃料显著不同的环境效益,并进一步探讨了氨作为储能介质的特点,包括储能密度和规模大、受地理条件约束小、便于运输存储等。本文还针对目前的合成氨路线从理论分析和工业实际两个方面对合成效率进行了估算和评价。针对目前国内核能、风能、太阳能等清洁能源电力的低谷或弃电问题,建议采用以制氨的方式存储或外运,以便于在电力不足时将其用于发电。建议并评估了几条基于制氨并发电的路线,并基于现有氨燃料的发电效率计算了各路线在全生命周期内的总储能效率（25%～40%）和以电换电的效率[2.5～4.0(度/10度）]。     

Empowering the electric grid: Can SMES coupled to wind turbines improve grid stability?

The transition to a low carbon energy portfolio necessitates a reduction in the demand of fossil-fuel and an increase in renewable energy generation and penetration. Wind energy in particular is ubiquitous, yet the stochastic nature of wind energy hinders its wide-spread adoption into the electric grid. Numerous techniques (improved wind forecasting, improved wind turbine design and improved power electronics) have been proposed to increase the penetration of wind energy, yet only a few have addressed the challenges of wind intermittency, grid stability and flexibility simultaneously. The problem of excess wind energy results in wind curtailment and has plagued large scale wind integration. NREL's HOMER software is used to show that a strong negative correlation exists between the cycles to failure of a storage device and the excess wind energy on the system. A 1 MJ magnesium-diboride superconducting magnetic energy storage (SMES) system is designed to alleviate momentary interruptions (lasting from a few milli-seconds to a few minutes) in wind turbines. The simulation results establish the efficacy of SMES coupled with wind turbines improve output power quality and show that a 1 MJ SMES alleviated momentary interruptions for ∼50 s in 3 MW wind turbines. These studies suggest that SMES when coupled to wind turbines could be ideal storage devices that improve wind power quality and electric grid stability.     

Asian international grid connection and potentiality of DC superconducting power transmission

In 2011, a large scale earthquake and tsunami hit the northeastern coast of Japan, and nuclear plants were damaged to a large extent. Before the Tsunami, 54 nuclear plants were operated, however presently, only three nuclear plants are in operation. Therefore, Japan is suffering from high price of electricity and low supply reliability. In generation mix, nuclear plants generate only one percent and 87 percent of electricity is generated by fossil energy. This is not preferable for Japan from the viewpoints of energy security and stable electricity supply. Therefore, it is mandatory to increase sustainable energy and to decrease consumption of fossil fuel. International grid connection and the Global Energy Interconnection will be one of countermeasures against these problems existing in Japan. In this paper, international grid connection initiatives proposed in Asia are described and features and issues of electric power grids in Japan are discussed to implement the international grid connection. As the key technology for implementing the international grid connection, the present status of DC superconducting power transmission lines and power converters for long-distance power transmission lines are presented. In conclusion, conditions and legal frameworks for realizing the international grid connection are described.