EE392N Lecture Two: The Power Grid and Grid Communications April 4, 2011 Dan O’Neill Seminar Course 392N ● Spring2011 ee392n - Spring 2011 Stanford University 1Intelligent Energy Systems

The Energy Grid Last time… Intro to the grid –Traditional grid –Change –Intelligent energy system Communications background –Grid communications today –Future requirements –Alternatives ee392n - Spring 2011 Stanford University 2Intelligent Energy Systems

Last Time: Intelligent Energy Systems Nearer term evolution of the grid leading to the Smart Grid Look at intelligent energy systems from a systems point of view Focus on information and management Time ee392n - Spring 2011 Stanford University 3Intelligent Energy Systems Traditional Grid Intelligent Energy Systems Smart Grid

Backup: Smart Grid The essence of this vision is “a fully– automated power delivery network that can ensure a two-way flow of electricity and information between the power plants and appliances and all points in between”. The three key technological components of the Smart Grid are distributed intelligence, broadband communications, and automated control systems. ee392n - Spring 2011 Stanford University 4Intelligent Energy Systems

The Energy Grid Last time… Intro to the grid –Traditional grid –Change –Intelligent energy system Communications background –Grid communications today –Future requirements –Alternatives ee392n - Spring 2011 Stanford University 5Intelligent Energy Systems

Traditional Grid Worlds Largest Machine! –3300 utilities –15,000 generators, 14,000 TX substations –211,000 mi of HV lines (>230kV) –SCADA control –Mostly unidirectional Capacity constrained graph ee392n - Spring 2011 Stanford University 6Intelligent Energy Systems

Interconnect ee392n - Spring 2011 Stanford University 7Intelligent Energy Systems

The Energy Grid 8 Distribution Conventional Electric Grid Generation Transmission Load DataManagement and Control Comm IT ee392n - Spring 2011 Stanford University Intelligent Energy Systems

Three Planes Electrical power –Supply(t)=Demand(t) –Real and reactive power Management and Control (MC) –Local protection systems –SCADA: Supervisory Control and Data Acquisition Data systems –Billing ee392n - Spring 2011 Stanford University 9Intelligent Energy Systems

Backup: Supervisory Control and Data Acquisition Collects, processes and displays system data –Coordinates resources –Displays problems Converging with standard –Communications –IT ee392n - Spring 2011 Stanford University Intelligent Energy Systems 10

Incorporating renewables – supply(t) Replacing old equipment, $1.5T –Electrical efficiency –Reliability –Embedded smarts Reducing operating costs –Excess capacity: Reserves –Bottlenecks: Transmission Deregulating The Traditional Grid is Changing ee392n - Spring 2011 Stanford University 11Intelligent Energy Systems $850B - grid $650B - users

Nearer Term Initiatives Renewables Demand Response Grid optimization All drive a need for IT and communication systems ee392n - Spring 2011 Stanford University 12Intelligent Energy Systems

Renewables System characteristics –Time varying –Inherent randomness! Issues –Centralized/uGrids? –Grid control and stability –Communications –Supply(t) < Demand(t) ee392n - Spring 2011 Stanford University 13Intelligent Energy Systems

Renewables: The System Problem National Renewable Energy Laboratory ee392n - Spring 2011 Stanford University 14Intelligent Energy Systems

15 Demand Response A method to reduce peak to average using variable pricing –Static - Look ahead –Dynamic pricing – Real time –Direct Load Control (DLC) – Utility directly reduces load –Interruptible tariffs – Large customers only Many issues –How communicate? –Consumer response? ee392n - Spring 2011 Stanford University Intelligent Energy Systems

Demand Response Campus and BuildingsHome AMI EMS Smart devices Whirpool Corp. made a public commitment to ship in 2011 a million dryers ready to plug into a smart electric grid, if communication standards ee392n - Spring 2011 Stanford University 16Intelligent Energy Systems

Grid Optimization Adjusting –Supply(t) –Connectivity Transmission routing Distribution Automation –Aggregating DR users Commercial buildings ee392n - Spring 2011 Stanford University 17Intelligent Energy Systems

The Energy Grid Last time… Intro to the grid –Traditional grid –Change –Intelligent energy system Communications background –Grid communications today –Future requirements –Alternatives ee392n - Spring 2011 Stanford University 18Intelligent Energy Systems

MC and Data Flow 19 Generators Transmission ’s KV IndustrialCommercialBusinessResidential Distribution 10-20KV ISO Substations Fiber and uWave Manual Slow speed wired and wireless/ nothing ?????? ee392n - Spring 2011 Stanford University Intelligent Energy Systems

Grid Communications Separate systems Reliable Secure Integrated Separate systems Reliable Secure Integrated Not integrated with existing communications systems Not visible on the Internet Not integrated with existing communications systems Not visible on the Internet ee392n - Spring 2011 Stanford University 20Intelligent Energy Systems

Intelligent Energy Network 21 Conventional Electric Grid Generation Transmission Distribution Load Intelligent Energy Network energy subnet Conventional Internet ee392n - Spring 2011 Stanford University Intelligent Energy Systems Cisco will talk about this…

Intelligent Energy Systems Communications Near Future –Transmission Area Network (TAN) –Field Area Network (FAN) –Neighborhood Area Network (NAN) –Home Area Network (HAN) ee392n - Spring 2011 Stanford University 22Intelligent Energy Systems

Comm. Performance Issues BandwidthLatencyReliabilityComments Field.5 /20Mbs10us-1 sec99.99Control and SCADA Neighborhood.1/5Mbps<50 msec99.99AMI Home1-10Kbps>10 sec?EMS HAN Separate energy net from home datanet? Can use Internet? Latency Transmission Queuing Comments: ee392n - Spring 2011 Stanford University 23Intelligent Energy Systems

Alternative Standards ZigbeeWiFi4G/WiMaxPLCcomments FieldX NeighborhoodMESHXEurope3 vs 50 HomeMESH Femto?X Smart MeterXXXX ee392n - Spring 2011 Stanford University 24Intelligent Energy Systems

Smart Grid Comm Overview Many competing ideas and standards Issues –Performance (interference) –Latency –Security ee392n - Spring 2011 Stanford University 25Intelligent Energy Systems

ZigBee ZigBee smart energy 2.0 standard (HAN) –~100ft –~250Kbs Many suppliers and very inexpensive Not compatible with PLC Open upper layers - Flexible IEEE Physical and Data link layers –Mesh –900Mhz/2.4Ghz DS-Spread Spectrum ee392n - Spring 2011 Stanford University 26Intelligent Energy Systems IEEE/NIST interface and data standards: Converged USNAP and EPRI home standard

Power Line Communications HomePlug Green Phy –10Mbs –IP Uses the AC lines –Historical use in Transmission –Distribution for AMI 500Kbs –Use in Europe is diff. than US HAN applications (Media) –10-200Mbps, OFDM –Multiple standards Questions –Reliability (Not a mesh) –Interference –Privacy ee392n - Spring 2011 Stanford University 27Intelligent Energy Systems

WiFi DAN – Mesh –802.11a backhaul –Upper layer routing optimization and security HAN - coexistence? –Interference –Reliability –Security IEEE standard x –2.4(g) /5Ghz (a), OFDM –Up to 200Mbs Tropos ee392n - Spring 2011 Stanford University 28Intelligent Energy Systems

3G/WiMax/4G FAN (EPRI) Issues –Priority - latency –Reliability – dropped calls –Cell phone companies Roughly –100Mbs downlink –50Mbs uplink IEEE standards –OFDMA –MIMO ee392n - Spring 2011 Stanford University 29Intelligent Energy Systems

Communications Challenges The last “hop” and in the home Distribution system network (transformers and EV’s) Reliability and security Hierarchical decomposition of functions and applications => grid management –IT structure –Communications systems Integration with Internet? ee392n - Spring 2011 Stanford University 30Intelligent Energy Systems

Next Week Dimitry will talk on Control and Monitoring Basics ee392n - Spring 2011 Stanford University 31Intelligent Energy Systems