Electrical Energy Supply System Energy Sources DSO, TSO and TDOs Substations and User Premises Note: The pictures of substations shown in this presentation are the property of POWER Engineers, Inc. courtesy of Ms. Ani Hyusein, copyright 2017. These may be reproduced but must not be altered or edited and copies must contain this acknowledgement.

Sources of Energy: Usage, Generators, etc. Energy Source Percent Use in 2017 Generator Type Efficiency Capital Investment Comment: Coal 34.1 CCGT ? Depends on gasification N.A. Use dropping rapidly in most countries, use expected to peak in China and India around 2025 - uneconomic, high CO2 and polution Natural Gas 25.6 Up to 58 % $ 700 M per GW In addition to high efficiency, CH4 produces twice the energy per pound of carbon because of H2 to water. Nuclear 22.6 Steam T. 33% Very high Sensible source but unpopular. Fail-safe is possible. Very high costs becauser of underdevelopment. Wind Turbines 6.3 Multipole PM 45% Changing ask me later Non-synchronous source; site sensitive. Hydropower 7.4 Multipole Wound Magnet 90% Limited Opportunity - High Limited deployment sites; potentially catastrophic failure at poor sites Photovoltaic 1.3 Silicon PD 20 - 22 % now; limit 30 % max; to date 27 % Going Down Non-synchronous source. Energy incident at full sun at sea level 1 kW per square meter. Practical yield 6 acres per MW in NE US. All Else - biomass, oil, geothermal 0.87 ? Probably 30 %   Efforts to use biomass may do more harm than good. Fusion ? Always the source of the future; still worth pursuing but no immediate utility.

The Whole System – In Principle: Distribution Substation Sources: Synchronous   Non- synchronous Sun and Wind Transmission Substation Home and Motor Transmission (>70 kV) and Distribution System (< 70 kV) TSO or DSO or TDOs are separate corporate entities from generation providers.

What Do Substations Look Like?

What Substations Do: Change Voltage Levels Automatically Adjust Delivery Voltages (Local or Centralized Decisions) Protect System from Shorts, Overloads, Load Dropout, Etc. Provide Isolation for Maintenance Control Reactive Power to Optimize Efficiency and Stabilize Renewable Sources Integrate Multiple Sources Including Variable Ones Change System Interconnect by Available Sources and Demand Monitor and Control Power Flow (SCADA – System Control and Data Acquisition)

The Formidable Transformer:

The Wiring Diagram (Schematic or “one-line”): 115 kV Transmission I/O Circuit Breaker 13.3 kV Distribution Out Capacitor Bank (? Fixed) 115 kV to 13.3 kV transformer with tap changer Manual Interconnect Switch for Isolation Ring bus for 115 kV with disconnects to isolate faults, redirect flow, and aid maintenance 69 kV Distribution Out

What Customers Do: Pay for Service Be Efficient: Reduce Demand by Efficiency of Use Participate in Demand Control to Balance Available Sources in Systems with Renewable Penetration Usually Industrial Customers with Sheddable Loads Participate in Planning by Expressing Priorities Someday Buy Electric Cars!??