1 Where Does Electricity Come From?

2 Overview of Electricity

3 Power Generation

4 Coal Pros  Cheap  Abundant  New technologies to help with emissions Cons  Environmental emissions (SO 2, NO x, PM, Mercury, etc)  Mining impacts Health & environment

5 Coal Fired Power Plant

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12 Advanced Coal Technologies Increases Efficiency to up to 65% - increased cost, materials etc.

13 Life Cycle of Coal-Fired Electricity

14 Nuclear Pros  No CO 2 emissions  Cheap?  Cons  Cheap?  High impact/low occurrence risk  No closure to life cycle

15 Natural Gas Pros  Cleaner than coal  Dispatchable Cons  Costs variability & uncertainty  Emissions  Supply questionable

16 Hydro Pros  Emissions very low  Opportunity for storage  Cheap Cons  Devastating to wildlife and surrounding area  Dependent on weather

17 “Renewables” Solar, Wind, Thermal, Tidal Pros  Low emissions  Resource requirements low  Energy independence Cons  Costs  Intermittency  Location  Not necessarily renewable

18 History of Electricity/Grid Electricity ‘system’ created in US 1881  Purpose was electricity for lights  1881 cost: 24 cents/kWh! (now ~10 cents)  Early 1900’s - intercity transmission lines 1930s-1950s: rural electrification, federally- run electric generating plants (hydro) 1950s- now: nuclear power, environ. controls, fuel costs, Three Mile Island

19 Where does my electricity come from? Creating generation mixes

20 What information do I need? 1. Type of nearby generators (Power plants, dams, windmills, solar arrays) 2. Proportion – amount of total generation made up by each type (40% type A, 30% type B, 30% type C) Generally state lines used as borders

21 Guesses for Pennsylvania?

22 Solar Intensity

23 Wind Intensity

24 Precipitation

25 Coal Deposits

26 US Generation Mix Other: Solar, Wind, Biomass, Geothermal, etc

27 Guesses for Pennsylvania?

28 Pennsylvania Generation Mix

29 Is that the whole story? What if power plants near me don’t generate enough electricity to meet my needs? Pennsylvania does, but what about California and New York?

30 Include Interstate Trading Lots of electricity transfer in the United States, especially following deregulation in 1996 Currently, interstate electricity transfer ignored, but it’s a big part of the market  25% of California power is imported  West Virginia exports 70% of theirs These numbers have a significant impact, so new generation mixes, which include trading, are created for each state

31 Where Does the Electricity Come From? Net Imports (TWh) Source: EPA eGrid

California Distances

33 Import-Export Model: Linear Optimization Classic transportation/distribution problem Using two matrices of data (27 x 27) 1. Distances from exporters to importers 2. Shipments of power from exporters to importers Minimize the sum-product of these matrices The “cost” of moving electricity from exporters to importers Subject to the following constraint All electricity in system needs to be “used” – each row/column in shipments matrix must sum to net surplus/deficit calculated from EPA data By changing the amounts in the shipments matrix

34 Completed Optimization Showing Electricity Transactions (Shipments) in TWh

35 California Transfers

36 The California Consumption Mix NOTE: Exporting states retain their original generation mixes

37 Overview Policy Problem: Should energy be transported from the source to the demand as fuel or electricity?  Economics  Environmental Impacts  Social Impacts

38 Overview of Problem

39 Group Activity Individually, take 2 minutes to decide which you think is best and why  Consider the life cycle stages  Consider economic, environmental and social impacts  Consider what infrastructure exists and what might need to be built new  Be ready to explain which option you think makes the most sense and why Compare thoughts with 2-3 of your neighbors. Share comments with the class

40 US Coal Supply and Population A ton of coal is shipped by rail an average distance of 800 miles

41 Life Cycle of Coal-Fired Electricity

42 Base Case Assumptions  Power Plants identical (SUPC – 40% efficiency, 75% capacity factor) Therefore base production ignored for comparison  1000 MW (plus compensation for 7% transmission line losses)  Approximately 1000 miles  No siting difficulties or grade crossing upgrades  Capital Rail – minimal new track capacity, new trains Transmission – new HVDC lines, substations Amortized over life of investment (cost of capital 8%)

43 Base Case Economic Results

44 Air Emissions (30 years)

45 Comparative Annual Energy Consumption

46 Some Alternatives Coal to Methane or Hydrogen Coal Slurry Pipeline AC Transmission High Temperature Superconductors Barge and Rail