Foreword
Chapter 1. SmartGrids: Motivation, Stakes and Perspectives
1.1. Introduction
1.2. Information and communication technologies serving the electrical system
1.3. Integration of advanced technologies
1.4. The European energy perspective
1.5. Shift to electricity as an energy carrier (vector)
1.6. Main triggers of the development of SmartGrids
1.7. Definitions of SmartGrids
1.8. Objectives addressed by the SmartGrid concept
1.9. Socio-economic and environmental objectives
1.10. Stakeholders involved the implementation of the SmartGrid concept
1.11. Research and scientific aspects of the SmartGrid
1.12. Preparing the competences needed for the development of SmartGrids
1.13. Conclusion
1.14. Bibliography
Chapter 2. From the SmartGrid to the Smart Customer: the Paradigm Shift
2.1. Key trends
2.2. The evolution of the individual’s relationship to energy
2.3. The historical model of energy companies
2.4. SmartGrids from the customer’s point of view
2.5. What about possible business models?
2.6. Bibliography
Chapter 3. Transmission Grids: Stakeholders in SmartGrids
3.1. A changing energy context: the development of renewable energies
3.2. A changing energy context: new modes of consumption
3.3. New challenges
3.4. An evolving transmission grid
3.5. Conclusion
3.6. Bibliography
Chapter 4. SmartGrids and Energy Management Systems
4.1. Introduction
4.2. Managing distributed production resources: renewable energies
4.3. Demand response
4.4. Development of storage, microgrids and electric vehicles
4.5. Managing high voltage direct current connections
4.6. Grid reliability analysis
4.7. Smart asset management
4.8. Smart grid rollout: regulatory needs
4.9. Standards
4.10. System architecture items
4.11. Acknowledgements
4.12. Bibliography
Chapter 5. The Distribution System Operator at the Heart of the SmartGrid Revolution
5.1. Brief overview of some of the general elements of electrical distribution grids
5.2. The current changes: toward greater complexity
5.3. Smart grids enable the transition to carbon-free energy
5.4. The different constituents of SmartGrids
5.5. Smart Life
5.6. Smart Operation
5.7. Smart Metering
5.8. Smart Services
5.9. Smart local optimization
5.10. The distributor ERDF is at the heart of future SmartGrids
5.11. Bibliography
Chapter 6. Architecture, Planning and Reconfiguration of Distribution Grids
6.1. Introduction
6.2. The structure of distribution grids
6.3. Planning of the distribution grids
6.4. Reconfiguration for the reduction of power losses
6.5. Bibliography
Chapter 7. Energy Management and Decision-aiding Tools
7.1. Introduction
7.2. Voltage control
7.3. Protection schemes
7.4. Reconfiguration after a fault: results of the INTEGRAL project
7.5. Reliability
7.6. Bibliography
Chapter 8. Integration of Vehicles with Rechargeable Batteries into Distribution Networks
8.1. The revolution of individual electrical transport
8.2. Vehicles as “active loads”
8.3. Economic impacts
8.4. Environmental impacts
8.5. Technological challenges
8.6. Uncertainty factors
8.7. Conclusion
8.8. Bibliography
Chapter 9. How Information and Communication Technologies Will Shape SmartGrids
9.1. Introduction
9.2. Control decentralization
9.3. Interoperability and connectivity
9.4. From synchronism to asynchronism
9.5. Future Internet for SmartGrids
9.6. Conclusion
9.7. Bibliography
Chapter 10. Information Systems in the Metering and Management of the Grid
10.1. Introduction
10.2. The metering information system
10.3. Information system metering in the management of the grid
10.4. Conclusion: urbanization of the metering system
10.5. Bibliography
Chapter 11. Smart Meters and SmartGrids: an Economic Approach
11.1. “Demand response”: a consequence of opening the electricity industry and the rise in environmental concerns
11.2. Traditional regulation via pricing is no longer sufficient to avoid the risk of “failure” during peaks
11.3. Smart meters: a tool for withdrawal and market capacity
11.4. From smart meters to SmartGrids — the results
11.5. Bibliography
Chapter 12. The Regulation of SmartGrids
12.1. The regulation and funding of SmartGrids
12.2. Regulation and economic models
12.3. Evolution of the value chain
12.4. The emergence of a business model for smart grids
12.5. Regulation can assist in the emergence of SmartGrids
12.6. The business models are yet to be created
12.7. The standardization of SmartGrids
12.8. Conclusion
12.9. Bibliography
List of Authors
Index
First published 2012 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:
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© ISTE Ltd 2012
The rights of Nouredine Hadjsaïd and Jean-Claude Sabonnadière to be identified as the author of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988.
Library of Congress Cataloging-in-Publication Data
Smart grids / edited by Nouredine Hadjsaïd, Jean-Claude Sabonnadière.
p. cm.
Includes bibliographical references and index.
ISBN 978-1-84821-261-9
1. Smart power grids. I. Hadjsaïd, Nouredine. II. Sabonnadière, Jean-Claude.
TK3105.S545 2012
333.793’2--dc23
2012006916
British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN: 978-1-84821-261-9
During the past century the energy supply to cities has changed dramatically. During the 19th Century, the major energy resource in cities was coal. Gas was used as a secondary energy source, produced from coal and distributed via a gas network, with one of the major applications being lighting which was a competitor for oil.
At the turn of the 20th Century, electricity was deployed as a secondary energy source. Again, lighting was a major field of competition, where automation and user friendliness were seen as the major advantages of electricity. In order to smooth out demand, other applications were promoted (drives, household equipment, etc.). Small, local grids were interconnected in order to further smooth demand and improve reliability while limiting reserves. This has led to the system as it is known today. Within the cities, radially operated electricity grids are installed at a low voltage, typically three-phase 230/400 V in continental Europe. At nodes, this grid is linked by a transformer to a medium voltage supply (in the order of 10 kV). The medium voltage grid is often designed as a meshed grid, but operated in a non-meshed situation. The electric energy is brought to the city by high voltage substations that are supplied by the meshed — thus redundant — transmission grid, offering international links.
In many cities, the gas network is transformed into a distribution grid for natural gas for heating purposes. Some countries have opted for heat networks instead.
Both the liberalization of the electricity and gas market and the drive towards an environmentally sustainable energy supply, incorporating the reduction of greenhouse gas emissions and the increased use of renewable energy resources and flow, are stimulating the interest of different stakeholders in the energy field. In the coming years, energy demand will become increasingly tailored to customer needs. Users are not really interested in energy as such, but in so-called energy services: lighting, transport, heating/cooling, information and communication technologies (ICTs), home appliances, etc. In addition to quality of service and cost reduction, total connectivity, energy “on demand”, service-oriented portfolio and flexible contract management will also play a leading role in fulfilling customer expectations.
The aim of this book is to describe the future electricity networks that will enable all energy services to become sustainable. Several chapters deal with the elements of the electricity system. Attention is not only given to the power elements of the transmission and distribution grid, but also to new types of demand, and especially to all aspects of control and system interactions.
The grid is defined as the system covering all wires and equipment that play a role in supplying consumers and providing access to generation technologies. Distributed generation will receive increasing attention over time and will become an integral part of cities’ energy systems, providing consumers and energy providers with safe, affordable, clean, reliable, flexible and readily-accessible energy services. Promoting and deploying distributed generation technologies should benefit energy consumers, the European energy system and the environment through the optimization of the value chain from energy suppliers to smart and large numbers of end users using SmartGrid infrastructure.
The SmartGrid developments aim to produce a set of “plug and play” interfacing modules using standardization and modularization, resulting in lower generation costs, material use, etc. This will lead to lower costs throughout the power delivery chain, given the stringent environmental framework and the market approach of the energy system. These plug and play interfacing modules are environmentally friendly (e.g. easy to recycle/reuse) and have very few to no unwanted effects on members of the public (they are not toxic, there is no interference, and they produce acceptable levels of EMF, etc.). The modules can, to a high degree, be customized to individual needs. Through standardization, modularization and programmable functionality, an economy of scales is possible leading to cheaper production, lower inventory costs and easily expandable and maintainable systems for the user. This can give Europe a competitive edge in the world market. This can offer the customer choice and quality of supply at relatively low cost, provided that minimal technical requirements are met and that these are measurable enabling network operators to maximize efficiency, flexibility and reliability through the use of advanced smart technology.
The variability of renewable generation, such as wind and photovoltaics, can have considerable effects on power system operation, mainly on security margins and consequently operational costs. This clearly requires integrated control of both central and distributed generation at all voltage levels. Given the necessary technological advancements and financial incentives, current operating practices based on centralized control need to move towards a decentralized approach. Technological developments in the ICT area (telecommunications, distributed control, advanced forecasting techniques, on-line security assessment, etc.) can contribute significantly to these developments. The grid interfaces to be developed have to include these elements in agreement with the results from the customer integration and effective demand-side management viewpoint. Possible synergies of distribution management systems and the impact of storage in power networks studies (peak load, power quality and penetration of renewables) need to be analyzed.
In general, simulation tools and methods for the analysis of distribution systems were historically developed and used in an off-line environment to study aspects of operation and development. Such tools have sometimes been upgraded and customized for use in an on-line environment for the purpose of generation dispatching, system state estimation and security analysis. The simulation and analysis software is orientated to conventional generation by centralized plants and unidirectional power flow.
A large number of micro-generators, uncertainties in distributed generation output (due to intermittent availability of renewable energy sources (RES) or dependence of distributed generation operation on other services such as heat demand driven combined heat and power (CHP)) and changes in power flows, especially at the distribution networks, are issues that cannot be effectively dealt with by methods and simulation tools that are widely applied. Moreover, distributed generators are often connected to networks through power electronics interfaces. New, advanced controllers based on power electronics and various types of storage devices are developed for distributed frequency and voltage control. These aim to support the network. There are limitations in the simulation of the commutation process in power electronic converters and in advanced digital control. Finally, aspects of data exchange and the communications requirements of network operation are largely ignored by the models.
Distributed network operators (DNO) need new methods and appropriate computing tools to correctly study the aspects of distributed generation network integration in order to anticipate technical problems and barriers, identify solutions, and underpin decisions on new investments. The novelty of the new problems requires the development of new mathematical approaches. Research must cover a range of topics relevant to the simulation and analysis needs for operation and the development of future electric networks. They should be confirmed through a discussion with the key stakeholders. The role of each actor and the relations required between the different actors need to be made clear. Questions — such as what is the role of the manufacturer? What type of data/information needs to be exchanged between the manufacturer and DNO? And what data need to be transmitted on-line for power network control and how? — need to be addressed.
There are several levels of decentralization of the network control that can be applied, ranging from a fully decentralized approach to hierarchical control. By using this distributed control strategy, the lower level of control can be independently operated and disconnected from the higher control hierarchy in order to form an islanded operation that has the ability to balance supply and demand locally with an acceptable power quality determined by local system requirements. Such control-independency enables parts of the network to be operated in two operation modes: autonomous (islanding) or grid-connected. This possibility increases the reliability of supply within the parts of the network penetrated by distributed generation, since their internal electricity resources can be used to supply their own demand during disruption in the public grid. On the other hand, in normal situations when the grid-connected mode is applied, the system resources — including the micro-sources — can be used and shared to supply system demand in order to achieve the maximum system economic efficiency.
The future active network will efficiently link small- and medium-scale power sources with consumer demands, allowing decisions to be made on how best to operate in real time. The level of control required for this is significantly higher than found in the present transmission and distribution systems. Power flow assessment, voltage control and protection require cost-competitive technologies and new communication systems with more sensors and actuators than presently used, certainly in the distribution systems. To manage active networks a vision of grid computing is created that assures universal access to computing resources. An intelligent grid infrastructure gives more flexibility concerning demand and supply, providing new instruments for optimal and cost-effective grid operation at the same time. Intelligent infrastructure enables the sharing of grid and information technology resources including ancillary services, balancing, microgrids behaving as virtual power plants, etc. It creates a framework for all grid users including the transmission system operators and DNOs.
In order to exploit the advantages of distributed generation (including RES) it is necessary to follow a “system approach”: distributed generation will not feed the network in a stand-alone mode, but will be fully integrated into the network. As is already the case for the high voltage network, the medium and low voltage networks will in turn become “active”. The energy generated by distributed generation will be dispatched accordingly and the distributed generators will have to provide ancillary services to the network and will become normal market participants.
Much of the equipment on the current electricity networks was installed with a design life of about 40 years, allowing for the anticipated increase in load over that period. An increasing proportion of the material is reaching the end of its design life. Meanwhile, the nature of the loads on the networks has changed beyond that predicted when planned and designed. The demand has doubled since the 1960s; peak demand and its timing are also changing and will continue to do so, in less than certain directions.
As very significant investments will be required to simply renew this infrastructure, the most efficient way forward is to incorporate innovative technologies and solutions when planning and executing this renewal. The approach to “design-in” greater network capability and functionality will also allow for the management of uncertainties and future, as yet unforeseen, changes.
Asset management is traditionally hindered by the old paradigms of reliability and the long pay-back periods (> 30 years) for the capital-intensive plants and grid equipment. The underlying uncertainty associated with recovery of long-term investments calls for an improved “knowledge” of the natural lifecycles of networks and their existing components. Any consideration of future electricity networks will also take into account the life-expectancies of future installed/refurbished assets — and the functional performance expectations (e.g. reliability, security, availability, accessibility, flexibility, adaptability, safety, environmental impact, aesthetic impact, operational impact, efficiency and whole-life cost) of all stakeholders with respect to those assets from installation to disposal.
The traditional design of network control systems with a centralized structure is not in line with the paradigm of the unbundled electricity system and decentralized control. In the unbundled and competitive environment, systems often work closer to their limits, and hence all system resources and services should be managed precisely to ensure a high level of reliability. The main goal from the viewpoint of defense and restoration is a “self-healing” network with a high level decentralized preventive control and outage management with automated network restoration. A main goal and objective should therefore be to achieve scalable, flexible supervisory control and data acquisition (SCADA) systems for network operations (SCADA for low voltage at the DSO level and customized automation applications).
As the chairman of the FP7 Technology Platform on SmartGrids, I warmly welcome the book that you have in hand. It is a concise contribution to the field and is brought to you by a number of well-known contributors that have carried out high-level research on different aspects of the future grid. I trust it will prove to be a major resource for the scientific and technical community.
Professor Ronnie BELMANS
Chairman Technology Platform on SmartGrids
European Union
March 2012
Power systems, after several decades of slow development, are experiencing tremendous changes due to several factors, such as the need for large-scale integration of renewable energies, aging assets, energy efficiency needs and increasing concerns about system vulnerability in the context of the multiplication of actors in free energy markets The complexity of operations is increasing, which will ultimately require the introduction of more intelligence in the grid for the sake of security, economy and efficiency, thus allowing the emergence of the “SmartGrid” concept.
The current operation of electrical networks is based on four levels resulting from the structure of the global electrical system:
– Power generation: most power is generated by large units installed in strategic locations for operation with respect to the power grid.
– The transmission system, which allows power to be transferred from large power plants to large consumption centers and other sub-transmission and distribution systems. This is the backbone of the whole power system, which contains sophisticated equipment and has highly centralized management.
– Distribution grids: these are at the interface between the transmission grid and the end user (the customer). They are connected to the transmission grid through “interface buses” called “substations” via transformers and, for economic reasons and simplicity of operation, are generally operated in radial structures. They are thus characterized, in the absence of significant local generation sources (interconnected at the distribution level), by unidirectional energy flows (energy traditionally always flows in the same direction, from the substation to the end user).
– End users are mostly passive customers characterized by “non-controllable” loads and do not contribute to system management.
The first three levels, although institutionally unbundled in a deregulated environment with responsibility domains clearly defined, are closely interdependent and are governed by specific physical laws, related in particular to the generation—consumption balance or to respecting technical constraints. This system as a whole was designed with the objective of generating, transmitting and distributing electrical energy under the best conditions of quality and economy. Regarded as the most complex system ever built by man, it is made up of millions of kilometers of lines and cables, generators, transformers, connection points, etc. It also integrates several voltage levels, sophisticated protection and control equipment and centers.
On the level of the French electrical grid, for example, there are some 1,300,000 km of electrical lines and cables. Moreover, most electrical systems on the level of a continent are interconnected (such as in Europe or in North America), giving a “gigantic” dimension to this system, whereas its control still remains limited in scale (performed on the level of each country, at best).
The control of this system is currently very centralized and arranged hierarchically on the level of each electricity company or each network operator, whereas any disturbance can potentially result in a wide-spread impact (on the level of the interconnected system). An example of this global disturbance effect is the outage of November 4, 2006 in Europe, where a disconnection of an electrical line in the north of Germany resulted in a large disturbance across Europe (partition of the interconnected zone in three areas of different frequencies, with a load shedding of 5,000 MW in France, etc.).
Similarly, in 2003 a line in Switzerland that was tripped resulted in a total blackout in Italy. A similar incident that occurred a month earlier in the USA also affected a large portion of the North-east US grid including Canada (about 50 million customers lost power). The specific feature of these disturbances is that they have affected several states (or countries) and electricity companies that are interconnected but do not have a global control system.
This system, which remained relatively stable for nearly a century, underwent significant changes at the end of the 20th Century. These changes were triggered by the liberalization of energy markets and its consequences, in terms of the multiplication of actors, partitioning of responsibility, lack of cooperation between system participants, etc.
Moreover, with the growing environmental concerns of our modern societies, building new electrical infrastructures such as overhead electrical lines and even generation units based on energy from fossil fuels has become increasingly difficult. Acceptance of such assets by local populations is decreasing (NIMBY or Not in My Back Yard syndrome).
These concerns, combined with requirements for security of supply, have led various institutional authorities to decide to set up regulatory incentives in favor of renewable energies, clean transportation facilities and energy efficiency, often linked to ambitious objectives. Some renewable energy units will be connected directly at the transmission system level, such as large wind farms. The smaller and medium-sized ones (often below several dozen megawatts) will be integrated into distribution systems. These last generation units are referred to as distributed generators.
The development of these energy sources has a strong impact on the traditional functioning of electrical grids, at the transmission system level as well as at the distribution system level.
Whereas transmission systems, considered to be the backbone of the electrical system due to their role in ensuring the generation—consumption balance and overall system security, are already well equipped with very sophisticated control and monitoring systems. Distribution systems have been designed differently for economic reasons, particularly because of their wide-spread and distributed nature. Indeed, distribution systems have not historically been designed to integrate a large number of generation units, namely decentralized or distributed energy resources.
Moreover, distributed generators are often intermittent in nature (photovoltaic and wind energy, for example). This implies specific management if their penetration rate becomes significant (beyond a certain threshold).
The end-user segment has also considerably evolved. Consumers, who were “passive” and did not interact dynamically with the electrical system, are currently in a transformation process, thanks notably to the development of the “smart meter” and related energy boxes. They can, for example, offer load control and response options, thus enabling them to participate in solving some network constraints, reducing peak demands or offering other services necessary to the system.
Moreover, with the development of distributed generation the end user can, while being a consumer, become a producer or source of energy storage. The consumer thus becomes “active” or even “proactive”, when all the possibilities of “load control”, “local generation” or “energy storage” are included depending on regulations, market design or available technologies. Similarly the expected development of the plug-in hybrid electric vehicle (PHEV) with its charging characteristics and storage possibilities, will contribute to the complexity of system management. These changes encourage engineers and researchers to devise new solutions to tackle the associated challenges while satisfying changing needs, avoiding over-investing in this system, while optimizing the whole energy chain.
The electrical network is a facilitator for all electrical uses and allows the added economic value to be increased for all components connected to it. This can be achieved thanks notably to the characteristics and capability of the power grid to geographically and temporally aggregate all different means of generation and widespread customers.
This power grid is now faced with an upheaval as significant as the advent of electricity. The solutions that will have to be imagined to tackle the challenges generated by these upheavals involve the introduction of more intelligence in the grid while taking advantage of advanced information and communication technologies (ICTs). All these considerations lead to the concept of an intelligent network or SmartGrids.
It is important to note that in this chain, for the reasons explained above, the distribution grids are in a particular position. They undergo a major paradigm shift, mainly because of their direct link with the traditional (end user) and new uses (PHEV). The advent of distributed generation, often of intermittent type, is increasing the requirement for preserving or even improving the quality of supply, and integrating new technologies (metering, storage, sensors, ICT-based equipment, etc.) into the existing infrastructure. Distribution grids are thus at the forefront of SmartGrid development to allow added value to be provided to all users who are connected to it.
The recent development of ICTs at reasonable cost offers possible solutions for the electrical system that were unimaginable only a few years ago. Thus, the possibility of installing meters with bidirectional communication with the network at the site of the end user, even with embedded intelligence for energy management, is changing the future vision of these networks. This interaction between the end user and the power system — whether it is through an energy supplier, an aggregator, a commercial broker or the distributor itself — can be done through various communication media, but have a direct impact on the electric system.
Electrical networks are already equipped with various means of communication as well as with sophisticated software for supervision and control centers. However, these technologies are usually dedicated to the transmission system, whose importance is predominant in overall security. There are also advanced technologies at the level of substations, such as the French digital control-command station that has a link to the transmission system. Likewise, one of the first applications of the Internet for business-to-business (b2b) use was in the field of electrical networks: namely to provide market participants with simultaneous and non-discriminatory access to the same information on available transmission capabilities for example. Beyond this application, the potentialities offered by the Internet have been (and still are) considered for various grid needs, such as Web-based services, applications not requiring real-time control, observation and monitoring with no critical information, etc.
On the level of the distribution system, the penetration of these technologies is much less visible. We can always mention the French example of the tariff signals through power line communications (PLCs) or the management of end users’ subscriptions during peak/off-peak hours. The democratization of ICTs, with equipment such as asymmetric digital subscriber line or “ADSL” boxes that bring and gather several media services at the end-user side and bidirectional communication possibilities offered by smart meters, however, has highlighted the opportunities that these technologies are able to bring to the flexibility of the electrical system.
ICTs for power grids exist as embedded software, whether at the level of components or control centers, and means of physical communication (PLC, dedicated lines, fiber optics, wireless, WiFi, ADSL, etc.). A particular interest is associated with the following functions:
– the smart meter with its different variants: broadband bidirectional communication, with or without load control tools and energy service, offers (intelligence) using different communication media;
– advanced devices for energy management and energy services (often called “energy boxes”) at the point of the end-user, which are either linked to smart meters or take advantage of ADSL potentialities;
– the intelligence associated with various domestic, tertiary or industrial consumption components, related to energy efficiency or the reliability of the power grid itself. The typical example is the intelligent and decentralized load-shedding of home appliances that act on the fluctuation of the grid frequency or voltage;
– observability, supervisory control and network management linked with generation and consumption. This concerns intelligent sensors and their management, the transmission and processing of an increasingly large volume of information, and the software-assisting grid operators for real-time application, including network security even at the level distribution systems (advanced distribution management system or DMS);
– the intelligence carried by “objects” or “devices” within the electrical network characterizing the following chain: measure, analyze, decide, act, communicate. We can find this chain on a set of applications, from protection and switching devices to decentralized voltage control and self-healing technologies. It is the concern of the whole distribution automation, with more specific functions on distributed and autonomous control capabilities.
These developments thus relate to a large range of technologies and affect all the participants interacting within the electrical system. It thus implies that all these pieces of equipment, actors and systems are interoperable.
The paradigm shift set out above — particularly at the distribution grid, the development of information technology and communications (ITCs), the increased maturity of certain components of energy conversion (based on power electronics) — are some elements that have contributed to the emergence of new technologies that will influence the evolution of these power grids. Some particular examples are discussed below:
– The smart or communicating meter: several countries have launched large-scale projects replacing conventional meters located with residential consumers with smart meters (this replacement operation involves tens of millions of meters, depending on the size of the network or the jurisdiction of the utility concerned). In France for example, a complete roll-out of 35 million of these smart meters is scheduled by 2018. Figure 1.5 depicts the structure of the French “LINKY” smart meter. Among the reasons why this change has become necessary, we can mention the introduction of competition and the possibility for customers to choose their energy supplier. Currently, in some countries the development of these meters is also linked to regulatory requirements (such as in Europe). This will allow residential load curves or profiles to be known. Reading of the meter is processed remotely and may therefore serve as a portal linked to other purposes, with regards to power quality and energy services for example. We can therefore expect some optimization in the management of customer consumption (such demand—response services at the appliance level, optimization of energy bills, bundled home services, remote maintenance, security, etc.). Beyond these aspects, we understand the potential of such devices for all value-chain stakeholders: consumers, energy providers, aggregators, grid operators, balancing entities, etc.
– Actuators integrated into the power grid: these are generally devices that are based on power electronics. They better manage power flows or other network variables, such as voltages or fault currents. Their use can also include the possibility of managing grid architectures in emergency conditions (fast looping and unlooping devices for radial architectures, superconducting or static fault current limiters, adaptive medium and low voltage compensators and voltage regulators, etc.).
– Fast switching devices and intelligent protection: significant progress has been made in switching devices, such as frequent operation remotely-controlled switches. The costs have therefore been reduced and the lifespan of the equipment increased which allows new network operating modes that were not previously possible. Such protections have also become more efficient and can self-adapt to their environment. Henceforth, we can envisage new patterns of grid operation enabling the management of a power system closer to its limits.
– High-performance and cost-effective sensors whether associated with existing devices or not: the distribution networks are, for example, very weakly equipped in terms of measurement devices, which poses the problem of observability. The emergence of inexpensive sensors combined with adequate communication possibilities opens up additional opportunities in terms of observability. Thus, distribution grids can be better controlled in real time. There are some devices that already incorporate these measurement possibilities, such as communicating fault passage indicators. Affordable sensors based on MEMS (micro electromechanical systems) technologies for distribution grids is an example of such advanced sensors. Affordable synchronized measurement units at the distribution level can also be included in the category of advanced sensors.
– Advanced energy management system and specifically DMS: these functions can be located in the traditional control centers or distributed/decentralized into distribution grids (intelligent substation or decentralized Supervisory Control And Data Acquisition [SCADA]). At the distribution level, for example, it allows the gathering of grid information at different locations and triggers real-time actions that were not possible until now.
– Energy storage devices: even though the potential for large-scale storage is now extremely small and the overall cost relatively high, we can expect significant developments in storage in the future, especially in relation to the development of intermittent renewable energy sources;
– Etc.
One of the structuring elements for these new technologies in the distribution system consists of ICT contributions. These technologies may offer great possibilities for innovation and flexibility at very low cost. They do, however, have a negative side in terms of the risks associated with these technologies (from the aspect of security).
The development of the European energy landscape is primarily influenced by factors such as:
– climate change and environmental concerns;
– security of supply;
– opening of the European domestic energy market and the integration of new Member States;
– aging infrastructures related to generation, transmission and distribution assets.
Thus, the European Union (EU) has recently adopted “the climate and energy package”, with ambitious sustainable development objectives such as:
– 3 × 20% for 2020, indicating the aim to reduce CO2 emissions by 20% compared to 1990; and
– to increase energy efficiency by 20% and increase the share of renewable energies to 20% (35% in the energy mix) within the existing electrical infrastructure.
This defines a way forward for the transition towards a more energy efficient and carbon-free society. All stakeholders in the electricity sector are affected and significant evolution is underway in the electrical grid to accommodate the assigned targets. This also implies heavy investment in low-carbon technologies and other technical innovations, which are seen as key enablers of this change.
Moreover, the EU generation assets need to be renewed, with an expected replacement (the retirement of about 300 GW) and expansion (of about 600 GW) of capacity by 2030, while consumption is expected to increase by an average of 2% per annum. The need for the renewal and expansion of transmission and distribution infrastructure, including the accommodation of renewable energy sources and distributed generation, is foreseen to represent about 850 billion euros by 2030 (source IEA).
The EU is very active in adopting renewable energy sources, particularly solar and wind energies. Thus, in 2008, 80% of the worldwide photovoltaic capacities were installed in Europe, an increase of 92.9% between 2007 and 2008 (+ 4,592.6 MWp). In 2010, the total EU-installed photovoltaic (PV) capacity has reached 29,327.7 MWp (22.5 TWh generated energy), representing a growth rate of about 120% on average [EUR 11].
Likewise, in 2008 the installed wind energy capacity of the EU reached 65.933 GW, i.e. 54.6% of the world’s installed capacity in that year [EUR 11]. In 2010, the capacity of wind power installed in EU countries reached 84,278 MW (about 10% of the total European electricity generation capacity) [EWE 11]. This represents an increase of 12.2% of installed cumulative capacity.
After being one of the most dynamic markets for wind generation (particularly driven by Germany and Spain), the rate of market growth has slightly decreased in the past couple of years (9,295 MW in 2010 compared to 10,486 MW in 2009).
In this landscape, it is interesting to highlight the special case of Denmark, which at an early stage faced the development of renewable energies, especially wind turbines. Figure 1.7 is an illustration of this evolution from the 1980s and later 1990s.
On the left of Figure 1.7, we can see the situation of power generation in the 1980s (centralized system).
On the right of Figure 1.7, we can see the power generation situation in the late 1990s (multiplication of distributed generation). This has forced Denmark to come up with innovative solutions for managing its electrical system beyond the back-up provided by its neighbors via interconnections. The concept of cell structures for system operation or EDISON (electric vehicles in a distributed and integrated market using sustainable energy and open networks) experimentation (pilot project) dealing with synchronization of the availability of wind energy with electric vehicles for charging or injection processes can be mentioned here.
The French market also followed this development, more specifically from 2005–2006, with improved regulatory inventive conditions. Figures 1.8 and 1.9 illustrate the remarkable evolution of the installed capacity for both PV and wind generation.
Thus, we can see the cumulated wind capacity installed multiplied by a factor of approximately 1,000 between 1996 and 2008. At the end of 2009, this capacity reached 4,400 MW (an increase of approximately 30% between 2008 and 2009). The installed PV capacity has more than doubled each year since 2006. However, it has to be noted that the recent revised regulatory laws on feed-in tariffs for grid-interconnected PV cells have resulted in some slowing of the increase in PV power being installed in the French market.
These energies are characterized by their intermittency, which makes it difficult to guarantee the power produced with the necessary accuracy during preparatory operations or the day-ahead market, even with the sophisticated forecasts that we now have. With the hypothesis of a lack of back-up generation (no sufficient reserves) with the required dynamics for system security and the current storage possibilities, the development of these energies without controlling their output powers can jeopardize the production—consumption balance and thus the security of the electric system as a whole.
This variability and lack of control of these generation units considerably affects the traditional grid operation schemes. Up to now, conventional generation units were perfectly controlled and adapted to the fluctuation of consumption. It is only in extreme cases that load shedding is needed. A growing part of generation is not currently controlled and consumption is characterized by its increasing spatial and temporal variability. Thus, the traditional solutions appear to be inappropriate to ensure the security and energy efficiency requirement, particularly in an insecure economic context (there is the need for investment optimization).
This significant evolution of the EU energy landscape represents remarkable technical, economic and social challenges. In this context, the sustainability targets issued by European policymakers cannot be achieved without a stepwise transformation of the existing network infrastructure into a SmartGrid.
The recent sharp increase in the price of oil and gas is a major concern for society. The case in France, for example, with regards to the share of electricity that comes from nuclear power argues for intensification of the electricity carrier as an energy vector. Furthermore, the development of renewable energy and the expected development of PHEVs favor this perspective. Some scenarios on the evolution of demand (consumption) in electrical networks in France show an average increase in consumption in the range of 1–2% per year, depending on the scenarios considered. In this forecast of consumption increase, despite the expected future gains in energy efficiency and conservation, the shift to electricity as an energy carrier is a significant aspect.
The phenomena and drivers of the SmartGrids concept are various, encompassing technical, economic and regulation aspects. Taking into account these elements, we can summarize the main triggers (a non-exhaustive list) leading to the concept of SmartGrids, as being:
– change of the energy paradigm, notably characterized by the advent of freedom of the energy markets, the development of distributed generation and the advent of renewable energies and the multiplicity of actors in this landscape which require:
- non-discriminatory access to the grid,
- management of the intermittency of renewable energies,
- management of the observability and dispatchability of distributed generation,
- etc.;
– the aging of the existing electricity infrastructure;
– a need to adapt the network for large-scale integration of distributed generation under the best security and economic conditions (the need for optimization of investments). This adaptation requires a more flexible network and flexible components, including better automation;
– technological innovations in terms of ICT, power grid equipment (fast circuit breakers/switch with frequent operations at affordable prices, protection, sensors, etc.) and smart meters that can embed intelligence for service offerings related to the optimization of consumption (consumer—energy provider interaction);
– increased need for quality of supply (which may vary depending on the application or any other criterion) including the security of energy supply;
– the need to face the increasing complexity of the electrical system in its spatial (interconnections) and temporal (dynamic) dimensions.
There are many different views of the SmartGrid concept. This makes clear the fact that although the main drivers for SmartGrid development are relatively similar in different parts of the world, the priorities are different. For example, within the EU, the challenge of the integration of renewable energies, energy efficiency and EU market integration in the framework of a carbon-free economy are priorities. In the US, however, blackouts, peak-demand situations and aging assets are the main priorities.
In China, the fast development of the grid, the need to integrate large-scale wind farms in the north and interconnecting the different provinces are immediate priorities, while the development of PHEV, PVs and microgrids are also fast-emerging issues. The EU Technology Platform1, for example, provides a very comprehensive definition of the SmartGrids concept, encompassing technological solutions, market issues, communication technology, standardization and regulatory regimes. Referring to the EU SmartGrids Technology Platform, the concept of SmartGrids is defined as an “electricity network which intelligently integrates the actions of generators and consumers connected to it in order to efficiently deliver sustainable, economic and secure electricity supplies.”
The US Department of Energy gives a more detailed definition of SmartGrids. It states that “a smart grid is self healing, enables active participation of consumers, operates resiliently against attack and natural disasters, accommodates all generation and storage options, enables introduction of new products, services and markets, optimizes asset utilization and operates efficiently, provides power quality for the digital economy” (source: US DoE).
Although there are several definitions and descriptions of the SmartGrid concept, it can be summarized as an integration of electricity infrastructure and the embedded/decentralized ICT (software, automation and information processing). The coupling of the two infrastructures provides the required “intelligence”