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The Smart Grid Enabling Energy Efficiency and Demand Response Clark W. Gellings. Chapter 7 : The Smart Grid - Enabling Demand Response - The Dynamic Energy Systems Concept. Brevard Community College ETP1400 Distributed Electrical Power Generation and Storage Bruce Hesher 433-5779.
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The Smart GridEnabling Energy Efficiency and Demand ResponseClark W. Gellings Chapter 7: The Smart Grid - Enabling Demand Response - The Dynamic Energy Systems Concept Brevard Community College ETP1400 Distributed Electrical Power Generation and Storage Bruce Hesher 433-5779
Dynamic energy management is an innovative approach to managing load at the demand side. • Dynamic Energy Management consists of four main components: 1. Smart energy efficient end-use devices 2. Smart distribute energy resources 3. Advanced whole-building control systems 4. Integrated communication architecture
Smart Energy Efficient End-Use Devices • Appliances, lighting, space conditioning, and industrial process equipment with the highest energy efficiencies technically and economically feasible. Thermal energy storage systems that allow for load shaping. Intelligent end-use devices equipped with embedded features allowing for two-way communications and automated control. Move from static devices to dynamic devices with distributed intelligence. Ex; High efficiency Internet Protocol (IP) addressable appliances that can be controlled by external signals from the utility, end-user, or an authorized entity.
Smart Distributed Energy Resources • On-site generation devices such as photovoltaics, diesel engines micro-turbines, and fuels cells that provide power alone or in conjunction with the grid. On-site electric energy storage devices such as batteries and fly wheels. Devices are dynamically controlled to supply base load, peak shaving, temporary demand reductions or power quality. Devices that are dynamically controlled such that excess power is sold back to the grid.
Advanced Whole-Building Control Systems • Optimize the performance of end-use devices and distributed energy resources based on optimal requirements, user preferences, and external signals. Controls that ensure that end-use devices only operate as needed. ex: automatic light dimming or reducing air circulation during low occupancy. Control with two-way communications. ex: sensors in rooms that detect high CO2 levels (low oxygen) and communicate it to the buildings control system. Local, individual controls that are compatible with a whole-building system. ex security, lighting, space heating etc. can all be controlled from a central unit. Controls that have the ability to learn from experience and apply it to future events.
Integrated Communications Architecture • Data such as pricing, demand reduction signals from the utility, day-ahead weather forecasts, or external alerts need to be communicated. Ex: ventilation systems could be remotely shut down in the event of a fire or chemical attack. End-use devices such as smart meters need to send data to external parties. An open architecture is needed so products from different entities can interoperate. The figure at right shows a dynamic energy infrastructure applied to a generic building. See p134 for details.
Energy Management Today • Current practices in energy management consists of seven main areas: 1. Energy audits to identify problems 2. Improvements to existing devices and processes to reduce energy demand and/or materials. Heat recovery and waste management are examples. 3. Replacement or retrofit of existing devices with energy efficient ones. 4. Load shaping strategies such as thermal energy storage that moves the load to off-peak hours. 5. Installation of controls to turn end-use devices on/off as required at the local and building level. 6. Demand response strategies to reduce peak demand temporarily. 7. Use of distributed energy resources to replace or reduce dependency on the grid.
Demand-Side Management • Demand-side management is the planning, implementation and monitoring of those utility activities designed to influence customer use of electricity in ways that will produce desired changes in the utility’s load shape and load. It includes the management of all forms of energy on the demand side; not just electricity. Groups other than electric utilities such as gas and water utilities are involved. On the user side companies and home owners are trying to reduce costs through managing their consumption.
Demand Response • Demand response (DR) refers to mechanisms to manage the demand from customers in response to supply conditions, for example, having electricity customers reduce their consumption at critical times or in response to market prices. Interest in demand response is being driven by tight supply conditions in certain regions of the country. • There are 2 principle types of demand response; incentive based demand response and time-based rates. To keep the demand from rising, utilities may offer financial incentives for things to reduce the demand or move it to off peak hours. FPL’s residential Program & Rebates: http://www.fpl.com/residential/energy_saving/programs/index.shtml FPL’s business Programs & Rebates: http://www.fpl.com/business/energy_saving/programs/index.shtml
Role of Technology in Demand Response The future growth of the demand response market capability depends on the cost, functionality and degree of process automation of technologies that enable demand response. Enabling technologies include: Interval meters (smart meters) with 2-way communication that allow customers to see their usage patterns and give them continuous access to their energy use data. Multiple, user-friendly, communications pathways to notify customers of real-time pricing conditions, potential generation shortages, and emergency load curtailment events. Energy information tools that enable access to interval load data, analyze load curtailment performance, and etc.
Demand reduction strategies optimized to meet differing high-price or electric system emergency scenarios. • On-site generation equipment used either for emergency backup or to meet primary power needs of a facility. Load controllers and building energy management control systems (EMCS) that automate load control strategies of end users. Areas that are already showing progress are automated meter reading (AMR) and web based energy information systems (EISs).
Current Limitations and Scope for Dynamic Energy Management • Currently, the demand response enabling technologies have limitations in terms of system scaling and interoperability with similar systems that impair their ability to be scaled up or serve an entire industry. • Individual demand response measures are often done in piecemeal fashion without integration of the different technology components. Measures can be put in place before open standards are created. Many demand response initiatives are designed to reduce peak demand not overall consumption. This is benefit to the utility but not the end-user.
Distributed Energy Resources p144 Distributed energy resources include technologies for distributed generation (non-renewable and renewable), combined heat and power, energy storage, power quality, and demand -side management and demand response. Distributed energy resources can be centralized or at the end user location. The principle purposes of distributed energy are: 1. To supply stand-alone power and/or heat for remote locations. 2. To augment power form the grid (reduce power purchases). 3. Reduce transmission and distribution losses. 4. To provide peak shaving or load leveling. 5. To guarantee power quality, reliability, and security. 6. To reduce capital cost of transmission facility construction.
How is Dynamic Energy Management Different? If the various energy resources, delivery system, and end user devices are linked together and controlled over a communications network (IntelliNetSM), there is significant potential to save energy and provide better service. Control must be as close to real time as possible and must adhere to the needs of both energy suppliers and consumers. One strategy is for the end user to reduce dependence on continuous quality power by employing local storage and power conditioning equipment. If you run off local stored power and “refill” during off-peak times, the power will cost less and peak demand is reduced.
Overview of a Dynamic Energy Management System Operation from an Integrated Perspective • A dynamic energy management system is comprised of highly efficient end-use devices, equipped with advanced controls and communications that enable them to dynamically communicate with external signals and to adjust their operation in response to those signals. Price signals, emergency status signals, and etc. can be received by local equipment which then reacts accordingly. • Users can specify trigger levels when power purchases or other adjustments occur, but emergency signals like could not be overridden. For example, if the distribution system is going into self preservation mode due to an approaching hurricane, local equipment needs to react accordingly.
Key Characteristics of Smart Energy-Efficient End-use Devices and Distributed Energy Resources (Together Referred to as “Smart Devices”) • High efficiency and a variety of distributed energy resources. • Have control and communication ability. • Have embedded processors to enable diagnostics and corrective actions. • Distributed resources will be able to synchronize efforts and send power or status information to the grid. • An “open” architecture to enable interoperability. • Need to be TCP/IP addressable for control and status. • Have ability to ”learn” things like building cooling rates and occupant habits.
Data Packets and Protocol Stacks • Data is encapsulated in packets by adding additional bits/bytes of routing information. On the sender side each layer adds routing data and passes the packet to the next lower layer. On the receiver side each layer reads the appropriate number of bits and sends the remaining to the next higher layer. The topmost layer is the application (program) and the lowest layer is the physical. A “Socket” is a an IP address and application ID.
Key Characterizes of Advanced Whole-building Control Systems • Building control systems need to incorporate the following functionalities: Receiving and processing information from sensors. Sending actuation signals for control devices. Learning physical characteristics of the building from sensor devices. Managing time-of-day profiles. Displaying system status to occupants. Obtaining command signals and overrides from occupants. Learning the preferences and patterns of the occupants. Receiving and displaying energy management and control signals such as pricing
Key Features of a Dynamic Energy Management System p151 • Incorporate End-User Flexibility Simplicity of Operation will be a key feature Leverage standard Information Technology (IT) platforms “Open Systems” architecture and Universal gateways are essential for integrating system operation. Integration with existing building energy management systems. “Open standards” and “Interoperability” Flat architecture essential for robust, low-cost systems
Conclusion • In addition to other features mentioned in this book, the smart grid must enable connectivity with customers in a dynamic systems concept. A lot of new software and hardware will be needed. There development must be done in an open standards manor to ensure interoperability. Existing technology, especially software, should be used to keep costs down and reliability high. Many information technology, electronics, and energy systems people will be needed.