BECOMING THE NEXT GENERATION (NXG) UTILITY

Transcription

1 WHITE PAPER / CAPITALIZING ON THE VALUE OF THE GRID BECOMING THE NEXT GENERATION (NXG) UTILITY BY Kenneth B. Bowes AND Michael E. Beehler, PE The value of the electric grid has never been greater, but the challenges of realizing that value have never been stronger. In the near future, new technologies, distributed energy resources (DER) and the grid of things will demand an even more robust, reliable and resilient electric grid.

2 WHAT S NEXT? The opportunity for regulated utilities to invest in the electric grid to become the NxG utility will be challenged by free market alternatives unrestricted by regulatory mandates or rate structures. How can the electric utility industry work with customers, regulators, shareholders and communities to promote a better appreciation and responsible transformation of the greatest invention of the 20th century? Technologies of the 21st century will allow the electric utility industry many productive opportunities to capitalize on the value of the grid. This paper will refresh our general understanding of the grid s value and address ideas for Figure 1: Targeting cost-effective investments creative investments that build upon that value for years to come. While sources into more efficient loads. Customers desire some of these investments are similar and incremental greater reliability and resiliency in the face of extreme compared to traditional investments, other investments weather events and manmade threats. They will need an expand the solutions utilities can provide for customers. information platform to satisfy an ever-increasing This will be especially important as customers seek to use demand for useful and easily accessible information the grid in different ways, regulators seek cost-effective that will enable comfort, convenience and more control solutions to policy mandates, and communities seek of their energy costs. alternative solutions for their energy needs. Resilient Integrated Information - Smarter Grid Modernization THE VALUE STATEMENT 1 Our industry needs a simple, understandable statement of value for the electric grid; an elevator pitch of sorts. The grid is valuable because: It s always there (with 99.97% reliability). It connects you to the lowest cost generation at any given time. It connects you and me so we can transact business if and when we choose. The grid of tomorrow (see Figure 1) will need to meet new and changing expectations of customers, offering more choices for integrating cleaner generation How does the NxG utility satisfy these heightened customer expectations cost-effectively? The answer is both simple and complex: by modernizing the grid to target investments in infrastructure that satisfy multiple needs for system resiliency, integrating more DER, and providing more information a smarter grid for customer choices and improved utility operations. RESILIENCY Today, resiliency means more than reliable service during extreme weather events. It means having the capability to provide backup power from an alternative utility source, DER that can operate independent of the grid, or various forms of emergency generation or storage systems. Providing customers with improved reliability with 2015 PAGE 2 OF 9

3 Level 5 Level 4 , Intranet, etc. Enterprise Network Site Business Planning and Logistics Network Enterprise Zone Terminal Services Patch Management AV Server Historian (Mirror) Web Services Operations Application Server Demilitarized Zone Level 3 Production Optimizing Historian Engineering Station Site Operations and Level 2 Supervisory HMI HMI Supervisory HMI HMI Area Supervisory Zone Level 1 Batch Discrete Continuous Hybrid Basic Level 0 Process Figure 2: Defense in depth model of control; logical overlay on SP99/Purdue model of control automatic restoration of the primary voltage system via loop schemes is not new. However, the deployment of single-pole switching devices in place of traditional threephase devices and new low-cost single-phase reclosing devices to replace fused cutouts will provide immediate improvements in reliability. Redundancy of utility supply will also improve the ability of generation, specifically residential solar photovoltaic (PV) generation (usually single-phase) to deliver kilowatt-hours (kwh) to the grid. By making targeted investments in resiliency, the dayto-day reliability can also be improved for customers, so the benefits can be realized before severe weather occurs. Resiliency also means prevention and mitigation of manmade physical and cyberthreats. Hardening critical substation assets using access control, video camera technology, improved fencing and enhanced physical barriers and ballistic protection can be layered into traditional designs. Promoting a defense in depth strategy for protection of cyberassets based upon national regulatory standards and practices (see Figure 2) reduces the risk of cyberpenetration. Physically separating the control systems level from other information technology systems and constantly performing diagnostics and penetration testing can achieve high levels of security. Redundancy in design can again mitigate such severe weather effects as substation flooding. At the same time, it can provide increased physical security and cybersecurity for substation assets. By investing in resiliency, the NxG utility builds a platform for further grid modernization that includes a dramatic expansion of DER and immediate reliability improvements, to the benefit of more customers PAGE 3 OF 9

4 WHITE PAPER / CAPITALIZING ON THE VALUE OF THE GRID Minimum Hosting Capacity Maximum Hosting Capacity Maximum Feeder Voltages (pu) ANSI voltage limit ,500 cases shown Each point - highest primary voltage Increasing Penetration (kw) Figure 3: Voltage rise on feeders with high penetration of solar PV 2 INTEGRATION Larger penetration of DER meets the policy objectives of many regulatory agencies and other stakeholders. Integration of DER means the NxG utility operator must deploy new systems and tools for managing daily operations. Much the same way transmission operations require real-time state estimating, SCADA control and automatic generation control, new and similar applications will be needed to manage DER. Applications such as volt/var control will be needed to mitigate the adverse effects of higher penetration of solar PV on utility feeder on voltage profiles. As more solar PV is added to the distribution system, voltages will rise and require constraints or a maximum hosting capacity be established to maintain the American National Standards Institute (ANSI) allowable voltage ranges (see Figure 3) By actively managing the volt/var controls, the NxG utility operator can mitigate any potential adverse impacts, such as overvoltage damage to equipment, and improve energy efficiency through conservation voltage reduction methods. This investment opportunity is a potential win-win for customers who choose to deploy DER and those who do not. By actively managing the feeder voltage levels, increased penetrations of DER will be possible and customers can obtain energy savings through benefits of conservation voltage reduction. Several studies and industry experience has shown that for a 1 percent voltage reduction there is a corresponding 0.5 percent to 1 percent energy savings. Replacing aging technology for load tap changer (LTC) controls, capacitor controls and line voltage regulation equipment can also PAGE 4 OF 9

5 benefit the NxG utility. Real-time monitoring and control of the voltage profile can help optimize system performance for customers. Specific investments in new controls, including single-phase capacitor controls, will allow increased use of residential solar PV by controlling voltage and VARs on each phase independently. By integrating the LTC controls with existing SCADA and other substation sensors, improved situational awareness and reliability will result. PV Storage Combined Integration of energy storage is Output Output Output another objective of many regulators and stakeholders focused on shifting Figure 4: Smoothing and ramping from energy storage 3 or mitigating peak electric demand. To achieve these objective additional capabilities, the NxG utility will have to actively manage the distribution system. The integration (DER) with clearly defined electrical boundaries that acts of monitoring and control (dispatching) of energy storage as a single controllable entity with respect to the grid and devices also can be used to smooth out the voltage profile can connect and disconnect from the grid to enable it to on utility feeders and provide more predictable frequency operate in both grid-connected or island mode. response during system events. This application is most often associated with the output variability of larger solar Microgrids can take on many forms, ranging from a single PV installations (see Figure 4) and corresponding adverse customer location to a campus-style environment or impacts to feeder voltages. By adding energy storage (in an entire bulk substation integrating several generation yellow) to the utility system, much of the power output sources (see Figure 5). Customers seek to sectionalize variability of the solar PV (blue) can be mitigated, allowing to an island mode of operation and return to the the interconnection of the DER without adverse impacts interconnected grid system when reliability or economics to other customers. dictate. Targeted microgrid opportunities exist to address customer needs for greater resiliency, improved Utility storage will become more cost-effective as the economics of DER and integration of renewable technology matures; however, certain existing applications energy resources. These opportunities could span a incorporate those operational benefits with economic broad spectrum from turnkey ownership and operations opportunities for demand response for kilowatt peak to becoming the microgrid operator with balancing shaving or shifting. responsibility or simply facilitating the interconnection process to the legacy system. The economics and As the NxG utility integrates these adaptive protection contractual issues surrounding microgrids are still evolving and control systems into the legacy system, the utility can and may hinder their development in the near term. deal with issues of reverse power flows and seamlessly allow for the development of microgrids. The Department of Energy (DOE) defines a microgrid as a group of interconnected loads and distributed energy resources Source: PNM 2015 PAGE 5 OF 9

6 Full Substation Microgrid Distribution Substation Bulk Supply Connection (Subtransmission) Single Customer Microgrid Gen Gen Other Feeders Partial Feeder Microgrid Load Feeder Load Gen Load Load Gen Full Feeder Microgrid Figure 5: Microgrid topology; microgrids can range in size from a single customer to an entire substation INFORMATION The need for more information about the real-time operation of the electric system both for the utility operator and the customer will require additional investment in sensor technology and telecommunications systems. A host of emerging sensor and protective relay technologies can improve reliability and restoration speed. Reliability and resiliency of the grid can be achieved by identifying faulted feeders and automatically redirecting power flows, predicting imminent failures of various components, or speeding the identification of fault locations in a more systematic fashion across large sections of utility systems. Using distribution feeder relays to pinpoint fault locations much like what is used to detect the distance to fault location for transmission line faults is gaining acceptance and improving restoration times and lowering costs. In many cases, the existing protective relay systems are coming to the end of their useful life, and this new technology provides for: replacement of aging assets; advanced protective features, including fast trip curves for worker arc flash safety; improved automation for restoration with SCADA capabilities; and future predictive reliability applications, such as high impedance fault detection. The desire is growing for real-time information and control of home energy systems to enable improved comfort, convenience, security and energy cost management. Home automation systems will integrate new electric generation sources, domestic hot water, heating/ ventilation/air conditioning, electric vehicle charging/ storage, and home security. The ability to manage home generation and loads will empower customers to better control their energy use. Grid modernization builds resiliency into a more integrated system that delivers more useful information to the NxG utility and the customer. The heart of a more modern grid is a robust communication network. Until recently, the cost of deploying communications to large numbers of remote data gathering and control locations was a barrier to implementation. However, today many alternatives address the last mile challenge with tiered network architecture. The telecommunications network (see Figure 6) shows a combination of technologies with various tiers that support a high-speed backbone ring for critical functions 2015 PAGE 6 OF 9

7 BACKBONE OPERATION CONTROL CENTER Figure 6: Multi-tiered telecommunications network like data centers, control centers and major facilities. A medium-speed network serves as a collection point to aggregate field data and backhaul to the high-speed network like substations or area work centers supplied with fiber or microwave systems. A low-speed network can reach the last mile or mobile applications like pole-mounted automation devices, advanced metering applications or mobile computing with private radio, radio frequency (RF) mesh networks or 4G public carriers. evolve and offer the distribution operator real-time control functions for traditional utility equipment, certain DERs and methods to reach into customer systems to access controllable loads. The deployment of low-cost sensors with increased communication options, together with the DMS, offers vastly improved situational awareness to the utility operator. At the same time, this smarter infrastructure will deliver improved information customers need to make informed energy use decisions. Figure 7 shows a proposed telecommunications architecture to achieve the objectives of a more resilient, integrated and smarter grid. Existing and proposed field devices appear at the bottom of the diagram. The methods for communicating with the field devices are shown in the access technologies row. The distribution and core technologies show how data from the field devices is communicated to centralized collector sites and then back to the control centers. While the heart of the modern system will be a robust telecommunications infrastructure, the brain of the system will be the integrated control systems of a distribution management system (DMS). These systems will continue to FIELD DEVICES Technologies ACCESS Technologies INTERFACE SITES DISTRIBUTION Technologies PTMP Radio INTERFACE SITES INTERFACE SITES CORE Technologies Fiber Mesh Fiber Major Transmission Data Centers Centers PTP Radio Leased Transmission Substations Radio Sites Cellular PLC Satellite Distribution Substations Poles Points Switch/Recloser Cap Bank LTC/Regulator Meter Transformer FCI Figure 7: Telecommunications architecture PAGE 7 OF 9

8 Investment Category Reduce Outage Impact Optimize Demand DER Integration Situational Awareness Distribution automation (SCADA) X X X Sensors and monitoring X X X Resilient Substation flood mitigation X Substation physical security X X Cybersecurity X X X Volt/VAR optimization X X X Integrated Energy storage X X X Integrated planning and modeling of DER X X X Microgrids X X X Advanced fault indication/prediction X X Information (Smarter) Telecommunications infrastructure X X X X Distribution management system X X X X Figure 8: Grid modernization investment summary CONCLUSION By modernizing the grid in an intelligent fashion, customers will receive improved blue sky reliability, enhanced resiliency, increased choices for connecting DER and better information to control their energy use. Utilities can also benefit through targeted investments that address aging assets, improve situational awareness and provide a more useful, smarter grid for their customers. See Figure 8 for a summary of the investment categories and benefits to reliability. There are many opportunities for electric utilities to capitalize on the value of the grid, beyond the integrated investments identified in this paper. Look for our next installment of this series Value of Grid: Choosing the Next Generation Business Model, where we will explore several emerging business models for electric utilities. Working with regulators and policy makers, electric utilities can develop comprehensive plans to improve resiliency, integrate higher penetrations of DER and enhance the information available for the customer, truly becoming the NxG utility. REFERENCES 1 Bowes K., Beehler M., Defining the Value of the Grid, IEEE, The Sixth Annual IEEE PES Conference on Innovative Smart Grid Technology, February Electric Power Research Institute, Integration of Distributed Renewables Program 174A: Modeling and Simulation, Arellano B., PV Smoothing and Shifting Utilizing Storage Batteries, Public Service of New Mexico, EPRI Smart Grid Demonstration Project Advisor Meeting, March 7, The Eversource Grid Modernization Plan, filed with the Massachusetts Department of Public Utilities, D.P.U /15-123, Aug. 19, PAGE 8 OF 9

9 BIOGRAPHIES KENNETH B. BOWES, VICE PRESIDENT OF ENGINEERING FOR EVERSOURCE ENERGY, Connecticut s largest electric utility, is responsible for engineering activities for the electric distribution system, including: distribution planning, distribution engineering and design, substation engineering, protection and control engineering, telecommunications engineering, and GIS for electric and gas operations. He establishes the reliability, asset management and system resiliency strategies for the annual program development and the five-year capital program. He also manages the distributed generation, microgrid, new technology and R&D activities for the company. Additionally, he executes the System Resiliency Program and the Stamford and Greenwich Infrastructure Improvement Projects. He serves as the lead witness for regulatory proceedings and serves as the Connecticut Incident Commander for system restoration activities. He earned a bachelor s degree in electrical engineering from the University of New Hampshire and a master s in electrical engineering from Rensselaer Polytechnic Institute. He is the past chairman of the Edison Electric Institute s Transmission Committee and serves on the EEI Transmission and EEI Security committees. MICHAEL E. BEEHLER, PE, VICE PRESIDENT, joined Burns & McDonnell as a senior transmission engineer and project manager in 1995, after 14 years with investor-owned electric utilities in Tucson, Arizona, and Honolulu, Hawaii. In the late 1990s, Beehler developed the application of reliability-centered maintenance to the transmission industry and, in late 2001, he helped lead Burns & McDonnell s initial development of the critical infrastructure security practice. He has written and presented several papers on reliability-centered maintenance, security and, in 2003, the application of program management in the transmission industry. Subsequently, Burns & McDonnell has been involved in the program management of numerous projects throughout the United States. He has written and presented extensively about the smart grid and has initiated the Sustainable Electric Energy Design (SEED ) process for substation design. He received his Bachelor of Science degree in civil engineering from the University of Arizona in 1981 and a Master of Business Administration degree from the University of Phoenix in He is a registered professional engineer in eight states, a member of IEEE and a fellow in the American Society of Civil Engineers PAGE 9 OF 9