19,659 research outputs found

    Electricity network scenarios for 2020

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    This report presents a set of scenarios for the development of the electricity supply industry in Great Britain in the years to 2020. These scenarios illustrate the varied sets of background circumstances which may influence the industry over the coming years – including political and regulatory factors, the strength of the economy and the level to which environmentally-driven restrictions and opportunities influence policy and investment decisions. Previous work by the authors (Elders et al, 2006) has resulted in a set of six scenarios illustrating possible developments in the electricity industry in the period up to 2050. While such scenarios are valuable in gauging the long-term direction of the electricity industry and its economic and environmental consequences, shorter-range scenarios are useful in assessing the steps necessary to achieve these long-range destinations, and to determine their relationship to current trends, policies and targets. In this chapter, a set of medium-range scenarios focused on the year 2020 is developed and described. These scenarios are designed to be consistent both with the current state of the electricity supply industry in Great Britain, and with the achievement of the ultimate electricity generation, supply and utilisation infrastructure and patterns described in each of the 2050 scenarios. The consequences of these scenarios in terms of the emissions of carbon dioxide are evaluated and compared with other predictions. The SuperGen 2020 scenarios described in this report were developed as a collaborative effort between the SuperGen project team and the ITI-Energy Networks Project team both based at the University of Strathclyde

    Low-carbon energy: a roadmap

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    Technologies available today, and those expected to become competitive over the next decade, will permit a rapid decarbonization of the global energy economy. New renewable energy technologies, combined with a broad suite of energy-efficiency advances, will allow global energy needs to be met without fossil fuels and by adding only minimally to the cost of energy services The world is now in the early stages of an energy revolution that over the next few decades could be as momentous as the emergence of oiland electricity-based economies a century ago. Double-digit market growth, annual capital flows of more than $100 billion, sharp declines in technology costs, and rapid progress in the sophistication and effectiveness of government policies all herald a promising new energy era. Advanced automotive, electronics, and buildings systems will allow a substantial reduction in carbon dioxide (CO2) emissions, at negative costs once the savings in energy bills is accounted for. The savings from these measures can effectively pay for a significant portion of the additional cost of advanced renewable energy technologies to replace fossil fuels, including wind, solar, geothermal, and bioenergy. Resource estimates indicate that renewable energy is more abundant than all of the fossil fuels combined, and that well before mid-century it will be possible to run most national electricity systems with minimal fossil fuels and only 10 percent of the carbon emissions they produce today. The development of smart electricity grids, the integration of plug-in electric vehicles, and the addition of limited storage capacity will allow power to be provided without the baseload plants that are the foundation of today's electricity systems. Recent climate simulations conclude that CO2 emissions will need to peak within the next decade and decline by at least 50 to 80 percent by 2050. This challenge will be greatly complicated by the fact that China, India, and other developing countries are now rapidly developing modern energy systems. The only chance of slowing the buildup of CO2 concentrations soon enough to avoid catastrophic climate change that could take centuries to reverse is to transform the energy economies of industrial and developing countries almost simultaneously. This would have seemed nearly impossible a few years ago, but since then, the energy policies and markets of China and India have begun to change rapidly -- more rapidly than those in many industrial countries. Renewable and efficiency technologies will allow developing countries to increase their reliance on indigenous resources and reduce their dependence on expensive and unstable imported fuelsAround the world, new energy systems could become a huge engine of industrial development and job creation, opening vast new economic opportunities. Developing countries have the potential to "leapfrog" the carbon-intensive development path of the 20th century and go straight to the advanced energy systems that are possible today. Improved technology and high energy prices have created an extraordinarily favorable market for new energy systems over the past few years. But reaching a true economic tipping point will require innovative public policies and strong political leadership

    Inertia emulation control of VSC-HVDC transmission system

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    The increasing penetration of power electronics interfaced renewable generation (e.g. offshore wind) has been leading to a reduction in conventional synchronous-machine based generation. Most converter-interfaced energy sources do not contribute to the overall power system inertia; and therefore cannot support the system during system transients and disturbances. It is therefore desirable that voltage-source-converter (VSC) based high voltage direct current (HVDC) interfaces, which play an important role in delivery of renewable power to AC systems, could contribute a virtual inertia and provide AC grid frequency support. In this paper, an inertia emulation control (IEC) system is proposed that allows VSC-HVDC system to perform an inertial response in a similar fashion to synchronous machines (SM), by exercising the electro-static energy stored in DC shunt capacitors of the HVDC system. The proposed IEC scheme has been implemented in simulations and its performance is evaluated using Matlab/Simulink

    A voltage-source inverter for microgrid applications with an inner current control loop and an outer voltage control loop

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    Distributed generation (DG) units are commonly inter-faced to the grid by using voltage-source inverters (VSI’s). Extension of the control of these inverters allows to improve the power quality if the main power grid is disturbed or disconnected. In this paper, a control technique is developed for a VSI working in island mode. The control technique is designed in the time domain, combining an inner current control loop with an outer voltage control loop. Voltage regulation under various linear and non-linear load disturbances is studied

    Overview of three-phase inverter topologies for distributed generation purposes

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    The increasing presence of single-phase distributed generators and unbalanced loads in the electric power system may lead to unbalance of the three phase voltages, resulting in increased losses and heating. Distribution network operators are seeking to install larger DG units (viz. >5>5kVA in Belgium) by means of three-phase connections instead of single-phase to reduce voltage unbalance. There are several possible topologies to connect the DG units to the three-phase distribution network. These topologies can be divided into three groups: the three-phase three-wire inverters, the three-phase four-wire inverters and the multilevel inverters. In this paper, an overview of the aforementioned topologies is given

    European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0

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    The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with specifi c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of specifi cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and specifi c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag

    A Review of Hybrid Renewable Energy Systems Based on Wind and Solar Energy: Modeling, Design and Optimization

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    In this chapter, an attempt is made to thoroughly review previous research work conducted on wind energy systems that are hybridized with a PV system. The chapter explores the most technical issues on wind drive hybrid systems and proposes possible solutions that can arise as a result of process integration in off-grid and grid-connected modes. A general introduction to wind energy, including how wind energy can be harvested, as well as recent progress and development of wind energy are discussed. With the special attention given to the issues related to the wind and photovoltaic (Wind-PV) systems. Throughout the chapter emphasis was made on modeling, design, and optimization and sensitivity analysis issues, and control strategies used to minimize risk as well as energy wastage. The reported reviewed results in this chapter will be a valuable researchers and practicing engineers involved in the design and development of wind energy systems

    Optimal integration of wind energy with a renewable based microgrid for industrial applications.

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    Wind energy in urban environments is a rapidly developing technology influenced by the terrain specifications, local wind characteristics and urban environments such as buildings architecture. The urban terrain is more complex than for open spaces and has a critical influence on wind flow at the studied site. This approach proposes an integration of the surrounding buildings in the studied site and then simulating the wind flow, considering both simple and advanced turbulence models to quantify and simulate the wind flow fields in an urban environment and evaluate the potential wind energy. These simulations are conducted with an accessible computational fluid dynamic tool (Windsim) implementing available commercial wind turbines and performed on a case study at Agder county in the southern part of Norway for an industrial facility specialized in food production. Several simulations were considered and repeated to achieve a convergence after adding the buildings to the domain, which mainly simulates the wind flow patterns, power density, and annual energy production. These simulations will be compared with previous results, which adapted different manipulation techniques applied on the same site where the elevation and roughness data were manipulated to mimic the actual conditions in the studied urban site. The current approach (adding the buildings) showed a reduction in the average wind speed and annual energy production for certain levels with increased turbulence intensity surrounding the buildings. Moreover, a feasibility study is conducted to analyze the techno-economic of the facility's hybrid system, including the planned installation of a wind energy system using commercial software (HOMER). The simulation results indicated that HOMER is conservative in estimating the annual energy production of both wind and solar power systems. Nevertheless, the analysis showed that integrating a wind turbine of 600 kW would significantly reduce the dependence on the grid and transform the facility into a prosumer with more than 1.6 GWh traded with the grid annually. However, the proposed system's net present cost would be 1.43 M USD based on installation, maintenance, and trading with the grid, without including self-consumption, which counts for approximately 1.5 GWh annually. Moreover, the proposed system has a low levelized cost of energy of 0.039$ per kWh, which is slightly above the levelized cost of wind energy but 2 to 4 times less than the installed solar panels
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