A very comprehensive “Smart Grid Overview” document has been produced by the ITU-T Focus Group on Smart Grids (FG Smart). The objective of this “deliverable” document is to enable readers to understand key concepts and objectives for Smart Grid and identify architectural models and required capabilities in the Information and Communication Technology (ICT) perspective.
More specifically, this document covers the following:
- Definition of Smart Grid;
- Objectives of Smart Grid;
- Conceptual model and reference architecture of Smart Grid;
- Fundamental characteristics of Smart Grid;
- Roles and key areas of ICT for Smart Grid;
- Architecture overview for Smart Grid; and
- Required capabilities for Smart Grid.
Goals and Objectives of Smart Grid
Efficient and reliable transmission and distribution of electricity is a fundamental requirement for providing societies and economies with essential energy resources. The utilities in the industrialized countries are today in a period of change and agitation. On one hand, large parts of the power grid infrastructure are reaching their designed end of life time, since a large portion of the equipment was installed in the 1960s. On the other hand, there is a strong political and regulatory push for more competition and lower energy prices, more energy efficiency and an increased use of renewable energy like solar, wind, biomasses and water.
In industrialized countries, the load demand has decreased or remained constant in the previous decade, whereas developing countries have shown a rapidly increasing load demand. Aging equipment, dispersed generation as well as load increase might lead to highly utilized equipment during peak load conditions. If the upgrade of the power grid should be reduced to a minimum, new ways of operating power systems need to be found and established.
In many countries, regulators and liberalization are forcing utilities to reduce costs for the transmission and distribution of electrical energy. Therefore, new methods (mainly based on the efforts of modern information and communication techniques) to operate power systems are required to guarantee a sustainable, secure and competitive energy supply.
The general goals of Smart Grid are to ensure a transparent, sustainable and environmental-friendly system operation that is cost and energy efficient, secure and safe. Objectives of developing the Smart Grid are quite different from country to country for their various demands and start points. However, the common objectives of a Smart Grid are clear and listed below:
- Robustness: The Smart Grid shall improve resilience to disruption to provide continuous and stable electricity flows, avoiding wide-area breakout accidents. It shall guarantee the normal and secure run of the electricity grid even under the instance of emergency issues, such as natural disasters, extreme weather and man-made breakage, and provides self-healing abilities;
- Secured operation: The Smart Grid shall enhance communication networks and information security of the electricity grid;
- Compatibility: The Smart Grid shall support the integration of renewable electricity such as solar and wind, has the capacity of distributed generation access and micro-grids, improve demand response functions, implement the effective two-way communication with consumers and satisfy various electricity demands of consumers;
- Economical energy usage: The Smart Grid shall have the capacity of more effective electricity markets and electricity trades, implement optimized configuration of resources, increase efficiency of the electricity grid, and reduce electricity grid wastage;
- Integrated system: The Smart Grid shall highly integrate and share information and data of an electricity grid, utilize the uniform platform and model to provide standardized and refined management;
- Optimization: The Smart Grid shall optimize assets, reduce costs and operate efficiently;
- Green energy: The Smart Grid shall solve problems of energy security, energy saving, carbon dioxide emission, etc.
The utilities of the Smart Grid shall address the following challenges:
- High power system loading;
- Increasing distance between generation and load;
- Fluctuating renewables;
- New loads (hybrid/electric vehicles);
- Increased use of distributed energy resources;
- Cost pressure;
- Utility unbundling;
- Increased energy trading;
- Transparent consumption & pricing for the consumer;
- Significant regulatory push.
- The key market drivers behind Smart Grid solutions are:
- Need for more efficient use of energy;
- Increased usage of renewable energy resources;
- Competitive energy prices;
- Security of supply;
- Ageing infrastructure and workforce
The priority of local drivers and challenges, will likely differ from country to country or by geographical region within a specific country.
Domains and Actors in the Smart Grid conceptual model
Actors in the Domain
The end users of electricity. May also store, and manage the use of energy. Traditionally, three customer types are discussed, each with its own domain: residential, commercial, and industrial.
The operators and participants in electricity markets.
The organizations providing services to electrical customers and utilities.
The managers of the movement of electricity.
The generators of electricity in bulk quantities. May also store energy for later distribution.
The carriers of bulk electricity over long distances. May also store and generate electricity.
The distributors of electricity to and from customers. May also store and generate electricity.
Communications Aspects of Smart Grid
The communication consists of the following two sub-planes or functional groupings.
Information Access. It determines the syntax and semantic of application related data. Given each specific domain, we shall define the format of data to meet the application/service requirements.
Communication Network. It enables the reliable, efficient and secured transmission of the application/ service specific data.
In the communication network, it is necessary to consider both the network architecture and performance measures to meet the application/service requirements, including the Quality of Service (QoS) and security of information transmission over the network. The detailed description is listed below:
For the network architecture, one shall consider different options, covering home area networks, access/neighbourhood area networks, and wide area networks, and the use of Internet-based technologies along with other choices.
For the QoS, one shall consider different metrics (i.e., end-to-end latency, bandwidth, jitter, and reliability) along with different types of applications (i.e., the amount of data needs to be transmitted in a given deadline in order to successfully accomplish a task). To be specific, the latency shall be very tight in SCADA system in comparison with the normal meter reading and configuration in Advance Metering Infrastructure (AMI). In the August 14, 2003, blackout, a contributing factor was the issue with communications latency in control systems. With the exception of the initial power equipment problems, the on-going and cascading failures will be primarily due to problems in providing the right information to the right individuals within the right time period. Service differentiation and prioritization may be required depending on the quality and type of applications, which are supported by the communication links. Many standards and protocols mentioned above contain the mechanisms to achieve differentiated QoS services. As an example, the admission control, queuing scheduling algorithms, Resource Reservation Protocol (RSVP) and others have been extensively studied to provide QoS in IP networks.
Furthermore, the confidentiality, integrity and availability of network must be addressed as well. Confidentiality is preserving authorized restrictions on information access and disclosure, including means for protecting personal privacy and proprietary information. Integrity is the guarding against improper information modification or destruction, and includes ensuring information non-repudiation and authenticity. Each classification displays the level of adverse effect the destruction of information can be expected to have on organizational operations, organizational assets, or individuals. A loss of integrity is the unauthorized modification or destruction of information. Availability ensures timely and reliable access to and use of information. Each classification displays the level of adverse effect the disruption of access to or use of information or an information system can be expected to have on organizational operations, organizational assets, or individuals.
Power grid information security and protection requirements have aspects of the control network for the operation of energy transmission and distribution (i.e., SCADA), computer networks (i.e., transmitting meter data) as well as enterprise Information Technology (IT) network for business. Although all networks require information security services for dealing with malicious attacks or providing protection against inadvertent errors, specific distinctions in attack and error types, and differences in performance requirements as well as organizational policies for them make their required security posturing quite different in those areas. Hence, we shall systematically analyze the vulnerabilities in Smart Grid, explore the space of attacks targeting different weaknesses of Smart Grid, and develop possible countermeasures against those attacks.
Section 6.3 of this document states the relationship with other Smart Grid Standards Development Organizations (SDOs) that ITU-T believes are doing credible work on Smart Grids. Those include: IEC, ISO/IEC/JTC1 (Special Working Group on Smart Grid, WG on Sensor Networks), ITU-R, ETSI, ANSI (TIA, ATIS), China Communications Standards Association (CCSA), and IETF. The three IEEE Smart Grid related standards are NOT listed and there is no reference to any IEEE Smart Grid activities. http://www.comsoc.org/Smart-Grid. Why not?
Section 7 examines the Characteristics of Smart Grid. Three key elements of Smart Grid are listed: Smart Grid Services/Applications, Communications, and Physical Equipment.
Section 8 provides the Role and Key Areas of ICT for Smart Grid
Section 9 is an Architecture Overview of Smart Grid from an ICT Perspective
Section 10 addresses the Required Capabilities for Smart Grid
Section 11 covers relevent Smart Grid activities of ITU-T Study Groups (SGs). These are listed in Appendix II.
Bibliograpy lists the NIST and IEC Smart Grid Roadmap documents
Comment and Analysis
This is a very comprehensive and complete look at Smart Grid from an ICT perspective. It’s interesting that ITU-T does NOT reference IEEE work on Smart Grid, particularly the IEEE standards for Power Line Communications Equipment (P1775) and Networks (P1901).