Showing papers on "Power station published in 2018"

Using peer-to-peer energy-trading platforms to incentivize prosumers to form federated power plants

Abstract: Power networks are undergoing a fundamental transition, with traditionally passive consumers becoming ‘prosumers’ — proactive consumers with distributed energy resources, actively managing their consumption, production and storage of energy. A key question that remains unresolved is: how can we incentivize coordination between vast numbers of distributed energy resources, each with different owners and characteristics? Virtual power plants and peer-to-peer (P2P) energy trading offer different sources of value to prosumers and the power network, and have been proposed as different potential structures for future prosumer electricity markets. In this Perspective, we argue they can be combined to capture the benefits of both. We thus propose the concept of the federated power plant, a virtual power plant formed through P2P transactions between self-organizing prosumers. This addresses social, institutional and economic issues faced by top-down strategies for coordinating virtual power plants, while unlocking additional value for P2P energy trading. The rise of prosumers has led to creation of virtual power plants and peer-to-peer trading to help manage a diverse and distributed array of energy sources. This Perspective proposes the federated power plant, which combines these concepts to meet some of their individual challenges and offer new value.

Review of the operational flexibility and emissions of gas- and coal-fired power plants in a future with growing renewables

Abstract: This paper reviews operational flexibility and emissions of gas- and coal-fired power plants today and in the future with higher renewables. Six study cases were considered: heavy duty gas turbines in simple and combined cycle, aero-derivative gas turbines, large-scale supercritical coal power plants and small- and mid-scale sub-critical coal power plants. The most critical operational processes and pollutants associated with these plants were identified. Then, data was collected mainly from manufacturers, but also from academic research and grey literature. The data was compared and analyzed. Detailed comparisons of the power plant characteristics as well as the current and future flexibility and emissions are provided. Furthermore, a method to quantify the ability of conventional power plants to back-up renewables and the expected benefits from improved flexibility is proposed and evaluated. Results show that gas-fired power plants are not only more efficient, but also faster and generally less polluting than coal-fired power plants. However, at their respective minimum complaint load, gas plants are less flexible and produced more NOx and CO emissions than coal-fired power plants. Results also show that on average, an improvement of approximately 50% to 100% on power ramp rates, minimum power load, number of major power cycles and emissions for these plants is sought in the future to complement renewables.

Targeted emission reductions from global super-polluting power plant units

Abstract: There are more than 30,000 biomass- and fossil-fuel-burning power plants now operating worldwide, reflecting a tremendously diverse infrastructure, which ranges in capacity from less than a megawatt to more than a gigawatt. In 2010, 68.7% of electricity generated globally came from these power plants, compared with 64.2% in 1990. Although the electricity generated by this infrastructure is vital to economic activity worldwide, it also produces more CO2 and air pollutant emissions than infrastructure from any other industrial sector. Here, we assess fuel- and region-specific opportunities for reducing undesirable air pollutant emissions using a newly developed emission dataset at the level of individual generating units. For example, we find that retiring or installing emission control technologies on units representing 0.8% of the global coal-fired power plant capacity could reduce levels of PM2.5 emissions by 7.7–14.2%. In India and China, retiring coal-fired plants representing 1.8% and 0.8% of total capacity can reduce total PM2.5 emissions from coal-fired plants by 13.2% and 16.0%, respectively. Our results therefore suggest that policies targeting a relatively small number of ‘super-polluting’ units could substantially reduce pollutant emissions and thus the related impacts on both human health and global climate. After developing a unit-based air pollutants emission inventory of more than 30,000 fossil fuel power plants operating worldwide in 2010, the authors find that retiring or implementing controlling measures on coal-fired power plants, representing 0.8% of global capacity, could reduce PM2.5 emissions from coal-fired plants by up to 14.2%.

Geothermal energy: Power plant technology and direct heat applications

Abstract: The transition from current fossil-fuel energy system towards a sustainable one-based requires renewable energy technology. Although geothermal energy presents its own particular challenges in comparison with other renewable energy technologies, geothermal energy has showed significant potential to reduce environmental impact and greenhouse gas emissions from electricity production. Advantages of geothermal energy are not only the generation of electricity in different plant configurations but also the direct application of heat in industry and household uses regardless of meteorological conditions. In this study, a research review is carried out on the aspect of geothermal energy development, assessing power plant technology and direct heat applications. Five power plant configurations are studied: single-flash, double-flash, dry-steam, binary and advanced. The thermodynamic aspects are addressed in order to consider them for future geothermal power plant analysis. Furthermore, the most common direct uses of geothermal heat are discussed. Results illustrate that Binary – Organic Ranking Cycle Power Plants might play a vital role in the exploitation of low temperature geothermal resources. Furthermore, it is identified a need for research in hybrid geothermal-solar-biomass configurations for poly-generation purposes. These configurations increase the energy output, increasing the thermal efficiency and increasing the life of the geothermal reservoir. Similarly, direct applications of geothermal heat present good opportunities for increasing the revenue of a geothermal project. Depending of the geographic zone, cascade configurations contributes to maximise the use of geothermal resources. Future research reviews should consider the financial, economic and policy aspects of geothermal developments along with the geology, geophysics, geochemistry, drilling, reservoir engineering and environmental aspects. The main goal of addressing these topics is to provide the state-of-the-art of geothermal development for developers, policy makers, researchers and communities interested in geothermal energy.

Current Emissions and Future Mitigation Pathways of Coal-Fired Power Plants in China from 2010 to 2030.

Abstract: As the largest energy infrastructure in China, the power sector consumed approximately half of China’s coal over the past decade and threatened air quality and greenhouse gas (GHG) abatement targets. In this work, we assessed the evolution of coal-fired power plants and associated emissions in China during 2010–2030 by using a unit-based emission projection model, which integrated the historical power plant information, turnover of the future power plant fleet, and evolution of end-of-pipe control technologies. We found that, driven by stringent environmental legislation, SO2, NOx, and PM2.5 (particulate matter less than 2.5 μm in diameter) emissions from coal-fired power plants decreased by 49%, 45%, and 24%, respectively, during 2010–2015, compared to 15% increase in CO2 emissions. In contrast to ever-increasing CO2 emissions until 2030 under current energy development planning, we found that aggressive energy development planning could curb CO2 emissions from the peak before 2030. Owing to the implemen...

Integrated Energy Systems for Higher Wind Penetration in China: Formulation, Implementation, and Impacts

Abstract: With the largest installed capacity in the world, wind power in China is experiencing a ∼20% curtailment. The inflexible combined heat and power (CHP) has been recognized as the major barrier for integrating the wind source. The approach to reconcile the conflict between inflexible CHP units and variable wind power in Chinese energy system is yet unclear. This paper explores the technical and economic feasibility of deploying the heat storage tanks and electric boilers under typical power grids and practical operational regulations. A mixed integer linear optimization model is proposed to simulate an integrated power and heating energy systems, including a CHP model capable of accounting for the commitment decisions and nonconvex energy generation constraints. The model is applied to simulate a regional energy system (Jing–Jin–Tang) covering 100-million population, with hourly resolution over a year, incorporating actual data, and operational regulations. The results project an accelerating increase in wind curtailment rate at elevated wind penetration. Investment for wind breaks even at 14% wind penetration. At such penetration, the electric boiler (with heat storage) is effective in reducing wind curtailment. The investment in electric boilers is justified on a social economic basis, but the revenues for different stakeholders are not distributed evenly.

A Review of Power Electronic Converters for Variable Speed Pumped Storage Plants: Configurations, Operational Challenges, and Future Scopes

Abstract: Pumped storage power plant has gained a high level of attention in recent years, mainly because of its ability to act as a large-scale energy storage option and to improve power system flexibility Doubly fed asynchronous machine with the partially rated power electronic converter is adopted in pumped storage plants to provide variable speed operation and improve energy efficiency This paper summarizes the power converter topologies in large rated variable speed pumped storage plant (VSPSP), also covers the suitability of each converter topology, modulation techniques, and parallel converter schemes Also, it presents operational issues of the parallel converter system in VSPSP such as the shutdown of the plant due to insufficient converter redundancy and lack of fault-tolerant control schemes, a power outage due to the inadequacy of converter protection system, and unbalanced power sharing due to circulating current Furthermore, the reliable mitigating/additional techniques are discussed for future research It concludes that the refinement of these aforementioned issues will provide continuous operation of the plant

Coordinated Control Strategies for Fuel Cell Power Plant in a Microgrid

Abstract: Solid-oxide fuel cell (SOFC) power plant plays a vital role in a hybrid alternative energy based microgrid due to its reliability and flexibility in power supply However, the control of SOFC is challenging in terms of providing a fast load tracking while maintaining the fuel utilization rate within a safe range To this end, this paper builds two basic coordinated control strategies (CCS) for power management of SOFC-based microgrid The first is “Fuel Cell follows Inverter” scheme, where fast tracking is preferred while SOFC may operate on the edge of the safety range The second is “Inverter follows Fuel Cell” scheme, where high security is guaranteed by sacrificing performance in load tracking To obtain a robust and simple scheme, energy balance principle is used in CCS such that PI controller is sufficient to fulfill the basic duties Moreover, a simple supervisory control strategy is proposed for microgrid to provide a reasonable power reference for SOFC The control system is designed and tuned based on an SOFC plant with inverter's average model The efficiency of the proposed strategies is validated via a grid-connected SOFC/photovoltaic microgrid

Influence of solar technology in the economic performance of PV power plants in Europe. A comprehensive analysis

Abstract: Solar technology development in recent years has facilitated access to solar PV systems at increasingly competitive costs. This paper analyses the influence of solar technology on the economic performance of different topologies of PV power plants. An economic model is proposed and used to identify the most suitable type of installation for a wide range of input parameters. One of the main input parameters of the model developed is the location of the power plant in one of the seven EU countries with the largest PV growth. Location affects not only the solar irradiation received by the solar modules but also the costs associated with both the installation and the operation of the power plants. A detailed review of the costs related to PV power plants is presented. The size of the power plant as well as the PV technology and tracking system implemented are additional inputs of the economic model. This paper reviews the technological evolution of the PV sector, focusing not only on improvements in solar cell efficiency but also on the types of installed technology around the world. The three most widespread specific PV technologies are further analysed to find the type of installation most suited to a given country. In addition to the traditional financial indices commonly used to evaluate the economic performance of a project, the minimum feed-in tariff remuneration indicator is proposed and estimated in this work. Results are thus of great interest to investors, policy makers, and other stakeholders interested in the development of PV power plants.

Resonance Attacks on Load Frequency Control of Smart Grids

Abstract: Load frequency control (LFC) is widely employed to regulate power plants in modern power generation systems of smart grids. This paper presents a simple and yet powerful type of attacks, referred to as resonance attacks, on LFC power generation systems. Specifically, in a resonance attack, an adversary craftily modifies the input of a power plant according to a resonance source (e.g., rate of change of frequency) to produce a feedback on LFC power generation system, such that the state of the power plant quickly becomes instable. Extensive computer simulations on popular LFC power generation system models which consist of linear, non-linear, and/or high-order items clearly demonstrate the effectiveness of the proposed attacks. As the attack has very low computational cost and communication overhead, it is easy to launch in resource-limited devices such as intelligent electronic devices. In our simulations, the attacker keeps modified input within the normal operating range so as to invade plausibility and consistency based attack detection methods and yet the modifications can quickly drive the system beyond the admissible boundary. Another interesting finding is that by maliciously modifying the input such as power load and tie-line signal over multi-area interconnection channels, a multi-area LFC power generation system could become unreliable more quickly than a single-area system. Finally, we propose countermeasures on the proposed attacks.

The potential of concentrating solar power (CSP) for electricity generation in Libya

Abstract: The rapid increase in energy demand and the limited resources of fossil fuel as well as the environmentally damaging effects, drive the world to find new options for sustainable electricity generation, which is represented by renewable energies. Concentrating solar power (CSP) is one of the most promising technologies in the field of electricity generation to tackle this issue with a competitive cost in the future. This paper presents an investigation of the potential of implementation of CSP plants in Libya. The socio-economic context, current energy situation of the country and different types of CSP plants are discussed. Moreover, an assessment of site parameters required for CSP plants including solar resources, land use and topography, water resources and grid connections are investigated in detail. In addition, thermo-economic simulation of a 50 MW parabolic trough power plant is performed. The simulation is conducted based on meteorological data measured by the weather station installed at the Centre for Solar Energy Research and Studies (CSERS) in Tajoura city. The performance results are compared with the reference plant Andasol-1 in Spain. Even though the proposed plant is located on the North coast where solar resources are at their minimum compared with other regions of the country, the outcome of the study proves that Libya is not only suitable but it can be economically competitive in the implementation of CSP technology.

A comprehensive review of cogeneration system in a microgrid: A perspective from architecture and operating system

Abstract: Several factors such as climate change, increment in fuel cost and digital technology era have lead to transformation of conventional grid into smart grid. Existing microgrid can be integrated with smart grid characteristics by various topologies, including cogeneration system where both electricity and thermal energy from single source of fuel can be produced. Cogeneration system has better efficiency, lower costs and able to reduce greenhouse gas emissions compared to singular conventional methods. This paper presents a comprehensive review of cogeneration system, covering the principle operation and types of prime movers available for use in power plant, building and industrial plant. Prime movers such as gas turbine, steam turbine, micro turbine, reciprocate engine and fuel cell are compared in terms of size (kW), efficiency and principal operation. This review also describes the hierarchical control system for cogeneration system; classified into three types, which are local, centralized and decentralized. This study tries to find the most suitable control strategy for certain cogeneration system by referring to the related standards available. A number of cogeneration applications in commercial buildings, including hospital, airport, shopping complex and hotel, are presented to show the effectiveness of the cogeneration system. Overall, this paper presents comparison between each prime mover technology, factors that influence the selection of prime movers, challenges and prospects of cogeneration system.