US Wind Energy Growth: Issues for 20% by 2030 Introduction to EE 551 January 12, 2009 James D. McCalley Professor of Electrical and Computer Engineering

Outline 1.Electric industry overview 2.What is a wind plant? 3.Problems with wind; potential solutions 4.Other technology options 5.National investment planning 6.Conclusions

1. Electric Industry Overview: Organizational Structure (N. America) 3 Investor-owned utilities: 239 (MEC, Alliant, Xcel, Exelon, …) Federally-owned: 10 (TVA, BPA, WAPA, SEPA, APA, SWPA…) Public-owned: 2009 (Ames, Cedar Falls, Dairyland, CIPCO…) Non-utility power producers: 1934 (Alcoa, DuPont,…) Power marketers: 400 (e.g., Cinergy, Mirant, Illinova, Shell Energy, PECO-Power Team, Williams Energy,…) Coordination organizations: 10 (ISO-NE, NYISO, PJM, MISO, SPP, ERCOT, CAISO, AESO, NBSO) Oversight organizations: Regulatory: 52 state, 1 Fed (FERC) Reliability: 1 National (NERC), 8 regional entities Others: Manufacturers, vendors, govt agencies, professional & advocacy organizations…

1. Electric Industry Overview: Existing resource mix; Retail Prices 4

1. Electric Industry Overview: Legislative Landscape Carbon policy: Obama admin favors cap ‘n trade Existing models: SO 2, RGGI ($3.5/ton), EU Coal plnt: $3.50/ton×0.925tons/MWhr=$3.2/MWhr=0.3¢/kWhr Subsidies: Fed PTC, REPI (must have renewals - last done 10/08), 2¢/kWhr State PTC (IA: 1.5¢/kWhr, small wind, UT, OK), sales/prop tax red Renewable portfolio standards (RPS) 32 states, differing in % (10-30), timing (latest is 2025), eligible technologies/resources (all include wind) Building transmission Multi-state transmission is very difficult FERC’s authority - national interest corridors Alternative: >3 states band (Uppr Mdwst Trns Dvlpmnt Initiative) 5

1. Electric Industry Overview: Predicted (US EIA, NEMS); May ’07 6

1. Electric Industry Overview: 20% by /08: www1.eere.energy.gov/windandhydro/ The report identifies what this future looks like 7

2. What is a wind plant? Overview

2. What is a wind plant? Tower & Blades 9 Manu- facturer CapacityHub Height Rotor Diameter 0.5 MW50 m40 m GE1.5 MW m Vestas1.65 MW70,80 m82 m Clipper2.5 MW80m89-100m GE2.5 MW75-100m100 m Vestas3.0 MW90m80, 105m Acciona3.0 MW m m GE3.6 MW104 m Siemens3.6 MW107m Gamesa4.5 MW128 m REpower5.0 MW126 m Enercon6.0 MW135 m126 m Weight (Vestas 1.65MW) Nacelle: 57 s-tons Rotor: 47 s-tons Tower: 138 s-tons

2. What is a wind plant? Electric Generator 10 generator full power Plant Feeders ac to dc to ac Type 1 Conventional Induction Generator (fixed speed) Type 2 Wound-rotor Induction Generator w/variable rotor resistance Type 3 Doubly-Fed Induction Generator (variable speed) Type 4 Full-converter interface

2. What is a wind plant? Type 3 Doubly Fed Induction Generator 11 Most common technology today Provides variable speed via rotor freq control Converter rating only 1/3 of full power rating Eliminates wind gust-induced power spikes More efficient over wide wind speed Provides voltage control

2. What is a wind plant? Collector Circuit Distribution system, often 34.5 kV 12

2. What is a wind plant? Offshore About 600 GW available 5-50 mile range About 50 GW available in <30m water Installed cost ~$2500/MW; uncertain because US cont. shelf deeper than N. Sea 13

3. Problems with wind; potential solutions Cost

15 3. Problems with wind; potential solutions Cost $1050/kW capital cost 34% capacity factor capital structure 7% debt cost; 12.2% eqty rtrn 20-year depreciation life $25,000 annual O & M per MW  20-year levlzd cost=5¢/kWhr Existing coal: <2.5¢/kWhr Existing Nuclear: <3.0¢/kWhr New gas combined cycle: >6.0¢/kWhr New gas combustion turbine: >10¢/kWhr Solution: Cost of wind reduces as tower height increases Tower designs, nacelle weight reduction, innovative constructn Carbon cost makes wind good (best?) option

3. Problems with wind; potential solutions Day-ahead forecast uncertainty Fossil-generation is planned day-ahead Fossil costs minimized if real time same as plan Wind increases day-ahead forecast uncertainty 16 Solutions: Pay increased fossil costs from fossil energy displaced by wind Use fast ramping gen Distribute wind gen widely Improve forecasting Smooth wind plant output On-site regulation gen Storage

3. Problems with wind; potential solutions Daily, annual wind peak antiphase w/load 17 Solutions: “Spill” wind Shift loads in time Storage Pumped storage Pluggable hybrid vehicles Batteries H 2, NH 3 with fuel cell Compressed air …others Daily wind peaks may occur at night Annual wind peaks may occur in winter Midwestern Region

3. Problems with wind; potential solutions Wind is remote from load centers 18

3. Problems with wind; potential solutions Wind is remote from load centers 19  Build transmission! $60 billion AEP plan

3. Problems with wind; potential solutions Wind is remote from load centers 20  Build transmission! $80 billion JCSP plan

3. Problems with wind; potential solutions Wind is remote from load centers 21 Transmission cost: a small fraction of total investment & operating costs. …And it can pay for itself: Assume $80B provides 20,000 MW delivery system over 30 years, 70% capacity factor, for Midwest wind energy to east coast. This adds $21/MWh. Cost of Midwest energy is $65/MWh. Delivered cost of energy would then be $86/MWh. East coast cost is $110/MWh.

4. Other technology options Energy sources Natural gas, clean coal, nuclear, biomass, biofuel, solar, deep geothermal, ocean, off-shore wind Small generation and demand side control Other carrier technologies pipeline (natural gas, liquid fuel), rail/highway, H2, NH3 22 Observation: some energy sources are more economic in certain regions than others…. At 810 Gw load, 1.5% growth, we need 660 Gw over next 40 years. What do we invest in?

4. Other technology options 23 GEOTHERMAL SOLAR Wind BIOMASS CLEAN-FOSSIL NUCLEAR But how much of each, & how to interconnect?

5. National investment planning A new level of energy planning All energy forms can be used in electric or in transportation Solution space is temporal (40 yrs), spatial (nation), and … Multiobjective:  Min cost, max sustainability, max resiliency Appropriate tools do not exist today Approach: Very fast multiobjective optimization Network flow modeling Decomposition methods High-performance computing 24

Conclusions 25 Greenhouse gas has made energy top US priority, and Obama administration is poised to act Energy and transportation infrastructure are capital intensive and very long-lifed An intense need for infrastructure planning tools No silver bullet; no technology should be zeroed But wind clearly has a large role to play Must address variability, antiphase peaks, and transmission needs Iowa well located to play major role in this work