Solar Energy Commercialization SEC598S19 Solar Energy Commercialization Session 04 Utility Operations 2 Generation, Transmission, Distribution Operations January 16, 2019

Session 04 - Value to class members A continuation of overview of the electricity business Generation, Transmission, Distribution Introduction to Operations

Utility Operations (References) B.Shively and J.Ferrare, Understanding Today’s Electricity Business, Enerdynamics, 2012 (www.enerdynamics.com) R.H.Miller and J.H.Malinowski, Power System Operation, McGraw-Hill, 1994 A.J.Wood, B.F.Wollenberg, G.B.Sheble, Power Generation, Operation,and Control, Wiley, 2014 US Energy Information Administration (www.eia.gov)

The Electricity Business - Introduction The Electricity Business is a complicated web: Consumers Generation Transmission Distribution Operations Delivery Chain Operations The Market Structures (Traditional and Restructured) Market Dynamics Regulation Ref [1]

The Electricity Business – Generation Ref [1]

The Electricity Business – Generation Ref [1]

The Electricity Business -- Generation Baseload Runs 24 hrs/day Nuclear, coal and natural gas, some renewables Some units run at minimum levels Intermediate Runs mid-morning to evening Combined-cycle gas, hydropower Units ramped up from minimum load Peaking Runs early-afternoon to early-evening Single gas turbine, hydropower, pumped hydropower Ref [1]

The Electricity Business – Generation Portfolio Ref [1]

The Electricity Business – Demand Side Management An alternative to generation is carry out a program that reduces the size of the electrical load (demand) Demand Side Management has as a main goal to reduce demand at peak periods Energy efficiency Demand response Demand Response Emergency demand response Economic demand response Ref [1]

The Electricity Business – Economic Demand Response Real-time pricing Customers pay hourly prices – same-day or day-ahead market conditions Voluntary load response Customers offered payment to curtail load (day-ahead) Curtailable capacity call Customers paid a capacity payment to allow utility the right to curtail load Automatic load response Same as above, but done automatically Ref [1]

The Electricity Business – Transmission Ref [1]

Sinusoidal Analysis – Three Phase Electricity At most power plants, AC electricity is generated in 3-phase format Many industrial customers expect 3-phase AC electricity Three voltage waveforms are produced (transmitted) with the same amplitude and frequency, but 1200 phase differences:

Sinusoidal Analysis – Three Phase Electricity Balanced 3-phase system – only wire voltage drops, no current (or voltage drops) in the neutral (ground) line The sum of the real power components are constant in time

The Electricity Business – Transmission Ref [1]

The Electricity Business – Transmission System Operations The generators and transmission systems must be operated in synch to respond effectively to customer demand Transmission line capacity is largely established by wire size and voltage High transmission voltages mean lower current and lower i2R power losses Ref [1]

The Electricity Business – Transmission System Operations Optimal capacity determined by three constraints Thermal/current constraints Voltage constraints System operating constraints Operations are carried out by The utility in the regulated market An Independent System Operator (ISO) in the deregulated markets Ref [1]

The Electricity Business – Distribution Ref [1]

The Electricity Business – Distribution System Operations Usually carried out by the utility A distribution operations center supervises the operation employing SCADA systems Monitor loads Status of circuit breakers Voltage levels and frequencies Power Factor and VARs Ref [1]

The Electricity Business – Overall System Operations The four interconnect transmission systems generally operate independently Within each interconnect, there are various control areas, and each has a system operator Vertically integrated utility Municipal utility Federal Power Agency Power pools (groups of utilities) Independent System Operator (ISO – also known as a Regional Transmission Organization (RTO)) System operators are coordinated through the North American Electric Reliability Corporation (NERC) Ref [1]

The Electricity Business – Overall System Operations NERC has established reliability standards (overseen by FERC) One important requirement is the following: Operators must plan for forecast demand but also a reserve factor to cover mis-forecasts and unplanned contingencies. The reserves equal the greater of A percentage of the forecasted loads The single most severe contingency Ref [1]

The Electricity Business – Scheduling Ref [1]

The Electricity Business – Scheduling Preferred schedule (Least-Cost Dispatch) Unit 4 ($25/MWh) – 200MW Unit 2 ($35/MWh) – 100MW Unit 3 ($40/MWh) – 80MW Above schedule is not feasible (Line B overloaded) Revised schedule (lowest to highest cost) Unit 1 ($45/MWh) – 80MW Transmission schedule Line A – 180 MW Line B – 200 MW Ref [1]

The Electricity Business – Scheduling Reserves Calculation Greatest single loss contingency – 200MW on Line B If Line A were also to be lost, reserves from Unit 1 would not be available So the safest place is to reserve 200MW for Unit 5 (expensive!) and 200MW reservation for transmission on Line C Ref [1]

The Electricity Business – Overall System Operations Planning Ancillary Services Automatic Generation Control Manages minute-by-minute fluctuations Load-following Resources Manages five minute fluctuations Spinning Reserves Units not providing power, but already synchronized ready in 10 minutes Non-spinning Reserves Supplemental Reserves Voltage Support Black Start Ref [1]