Virginia Solar Pathways Project Training Session Module I: Electric Industry Background. US DOE Award No. DE-EE

Transcription

1 Virginia Solar Pathways Project Training Session Module I: Electric Industry Background US DOE Award No. DE-EE

2 Solar Pathways Project Goal: To Develop a Common Foundation of Technical & Regulatory Understanding 2015 Dominion

3 Utility Industry Overview 2015 Dominion

4 What is Electricity? Electricity Conductor Insulator The flow of electrons through a conductor The process of electrons moving by the application of an external force Materials used to conduct electricity that allow electrons to move freely Examples: Copper Wire & Aluminum Materials that do not allow electrons to move freely making it non-conductive Used for safety and protective gear Examples: Rubber, Glass & Porcelain 4

5 Electric Current Electrical Circuit a closed loop for electrons to move Closed Circuit = electrons flowing Open Circuit = electrons not flowing Current the flow of electrons in a conductor Voltage pressure in circuit (i.e., volt) Resistance slows the flow of electricity Given multiple paths, electricity will follow the path of least resistance 5

6 AC vs. DC Current Alternating Current (AC) Electrons move in one direction for a short period of time, then reverse directions Produced by power plants Power available in your house/business in a wall socket Direct Current (DC) Electrons constantly move one direction Produced by solar, batteries, & fuel cells AC vs. DC DC must be converted to AC using an inverter prior to use 1 MW AC = ~0.8 MW DC 6

7 Frequency Number of cycles in a second Units: Hertz or Hz Direct Current (DC) does not have a frequency Smaller Hz = Less Cycles, Larger Hz = More Cycles Example: 230 Volt at 50 Hz vs. 110 Volt at 60 Hz 7

8 Utility Overview Basic Operating Functions: Generation - where electricity is produced Transmission - high-voltage system of wires that transports electricity over long distances Distribution - low-voltage delivery area where electricity is delivered to final customers 8

9 Regional Transmission Organizations Regional Transmission Organization (RTO) Moves electricity over large interstate areas Independent third-party that manages the grid FERC Order 2000 o Drove Initiative by Encouraging Utilities to Join an RTO 9

10 PJM What is PJM? Pennsylvania, New Jersey, Maryland (PJM) Interconnection An RTO that is part of the Eastern Interconnection Coordinates the movement of wholesale electricity across 13 states and the District of Columbia Neutral, independent party that helps ensure grid reliability utilizing long-range planning procedures Which States are Served? Delaware Maryland Pennsylvania District of Columbia Michigan Tennessee Illinois New Jersey Virginia Indiana North Carolina West Virginia Kentucky Ohio 10

11 Generation 2015 Dominion 11

12 Load Load a customers instantaneous demand for energy Reserve Margin the amount of additional generation capacity built above forecasted demand to ensure enough power is available to meet maximum load at all times Currently, electricity cannot be efficiently and economically stored so it is constantly generated and supplied to customers 12

13 Generation Terms Capacity Maximum electric output available at an instantaneous moment Measures aggregate customer demand (load) and generation capacity Units: Gigawatt (GW), Megawatt (MW), Kilowatt (kw), or Watt (W) 1 GW = 1,000 MW = 1,000,000 kw = 1,000,000,000 W Energy Amount of electricity generated over a period of time Electric Output x Time = Energy Units: Gigawatt Hour (GWh), Megawatt Hour (MWh), Kilowatt Hour (kwh), or Watt Hour (Wh) Capacity Example: A 100 Watt Bulb (Capacity) burning for 10 hours would use 1,000 Wh of Energy (1kWh) Energy 13

14 Generation Terms Heat Rates The efficiency of a power plant How much fuel is required to create energy Power Plants with a higher heat rate are less efficient than those with a lower heat rate Heat Rate = Fuel Burned / Energy Generated Capacity Factor Average percentage of full capacity used over a period of time Capacity Factor = Energy / (Capacity x Time) 14

15 Central Power Plants Turbine Cluster of blades that spin shaft from external force Generator Converts mechanical energy into electrical energy using magnets 15

16 Transmission & Distribution 2015 Dominion

17 Transmission & Distribution (T&D) Transmission (T) High-voltage system of wires that transport a large amount of electricity over long distances Distribution (D) Low-voltage delivery area where electricity is delivered to final customers Losses Caused by heat from the resistance imposed on electrons Losses can range from 2 10% depending on the voltage and length of line 17

18 T&D Lines Different types of lines are needed based on how far electricity needs to travel Lines have a large range of voltages & sizes: Underground Lines 18

19 Voltage What is Voltage? Force or pressure in an electrical current between two points Voltage (i.e. Pressure) = Resistance x Current (i.e., Flow) Greater voltage = Greater flow of electrical current Voltage In Action 19

20 Transmission Lines Carry power long distances efficiently from a generating source to a central point Bulk transfer of electrical energy with a low amount of losses When transmission lines reach a substation or switching station, voltage is raised or lowered Generally operate at voltages greater than 69,000 Volts 20

21 Transformer & Substations Transformer Converts transmission voltages down from high-voltage to low-voltage and up from low-voltage to high-voltage Distribution Substation The interface between transmission and distribution Converts distribution voltages down to voltages suitable for residential, commercial, and industrial use 21

22 Distribution Lines Underground & Overhead Deliver electricity from distribution substation to customer Low quantity of energy transferred short distances with higher losses Generally operate at voltages less than 35,000 Volts 22

23 Solar Overview 2015 Dominion 23

24 How Does Solar PV Work? Cells in a solar panel use the energy of photons to dislodge electrons from their atomic bonds Process depends on: Temperature Wavelength of the light Material Composition 24

25 Questions? 2015 Dominion 25