Wind & energy

College of Engineering

Discovery with Purpose www.engineering.iastate.edu

Iowa State University WESEP REUJune 11, 2012

Wind & energyJames McCalley (jdm@iastate.edu)

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Homework

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DOE20by2030 report:•Full report:http://www.nrel.gov/docs/fy08osti/41869.pdf •Summarywww.nrel.gov/docs/fy11osti/49975.pdf

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Overview (focus mainly on US)• Preliminary energy concepts• Background on wind power

growth• Policy issues for wind energy• Wind energy in context• Grand challenge questions

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Some preliminaries• Power: MW=1341HP.• Energy: MWhr=3.413MMbtu (106btu); 1btu=1055joules• E=P×T• Run 1.5 MW turbine at 1.5 MW for 2 hrs: 3 MWhrs.• Run 1.5 MW turbine at 0.5 MW for 2 hrs: 1MWhrs

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Power, P Time, T Energy, ECapacity, Prated

T

P(t)dtE0Time, t

Power, P(t)1.5 MW

8760

8760

0

ratedP

P(t)dt

CF

• If P varies with t: • Capacity factor:

A lawnmower engine is 3HP (2.2kW or 0.0022 MW).Typical car engine is 200 HP (150kw or 0.15MW).Typical home demands 1.2kW at any given moment, on avg. 1MW=106watts106w/1200w=833 homes powered by a MW.Ames peak demand is about 126MW.The US has 1,121,000MW of power plant capacity.

1 gallon gasoline=0.0334MWhr; Typical home uses 11000kWhrs=11MWhrs in 1 year (about 1.2kW×8760hrs).1 ton coal=6MWhrs.

Actual annual energy production as a percentage of annual energy production at Prated

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Worldwide

Source: RenewableS 2011, Global Status Report5

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Worldwide

Source: BTM Consultants, www.btm.dk/reports/world+market+update+2010

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Background on Wind Energy in US

US Generation mix

Wind & renewables are 3.6% by energy.

Source: AWEA 2010 Annual Wind Report 7

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Background on Wind Energy in USU.S. Annual & CumulativeWind Power Capacity Growth

Source: AWEA 2010 Annual Wind Report 8

But what happened in 2010, 2011?

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Background on Wind Energy in US

Source: AWEA 2011 Fourth Quarter Market Report9

2010 is different! And 2011 is not much better. Why?

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Why was wind growth in 2010/2011 less than in previous years?

Poor 2008-2009 economy:• Less willingness to load, to build projects• Less power demand!

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Declining natural gas prices

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Background on Wind Energy in US

Percentage of New Capacity Additions.

Source: AWEA 2010 Annual Wind Report 11

N. GASWIND

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Cur US/Can nat gas production= 26Tcf/yrProven reserves=260Tcf: R/P=10yrsProve+unprove reserves=2372Tcf: R/P=91

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Risks of a very high gas-electric future:•Lifetime: Infrastructure investments live for 40-60 years and are not easy to “turn” once developed. •Diversification:

Today’s national energy system portfolio consists primarily of electric (coal, nuclear, gas, renewables), heating/industrial (gas), & transportation (petroleum). A high gas-electric future, with transportation electrification, will decrease portfolio diversification, creating a national vulnerability.

•Cost: Is heavy gas-electric investment the lowest cost option in terms of long-term {investment+production}?•Depletability: R/P ratios 10-90 yrs - what will be price effects as gas depletes?•Fracking: How much will public resistance grow?•CO2 emissions: Will coal-to-gas shift reduce it enough?

Alternative future: •Reduce coal in electric sector while growing gas & pipelines equally with wind+electric transmission. Co-optimize gas pipeline & electric transmission.•Replace significant petroleum for light-duty vehicles with CNG vehicles & PHEVs.•Conjecture: This approach will reduce CO2 more than a high gas-electric approach and will result in greater diversification of energy resources.

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Top 20 states

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Source: AWEA 2011 Third Quarter Market Report

14 of top 20 are in the interior of the nation. Top 3 coastal states are West. East coast is light on wind but heavy on load.Implication?

3 options for East coast use of wind:Build high cost inland wind, go offshore, or use transmission to move it from Midwest

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Source: AWEA 2012 First Quarter Market ReportU.S. Wind Power Capacity By State

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Background on Wind Energy in US

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Source: AWEA 2010 Third Quarter Market Report

Source: AWEA Wind Power Outlook 2010

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Background on Wind Energy in US

Market share of total 2008 wind installations

Source: AWEA 2009 Annual Wind Report 17

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Background on Wind Energy in USOwnership by company and by regulated utility

Source: AWEA 2009 Annual Wind Report 18

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Background on Wind Energy in US

Wind plant size

Source: AWEA 2009 Annual Wind Report 19

College of EngineeringBackground on Wind Energy in US29 states, differing in % (10-40), timing (latest is 2030), eligible

technologies/resources (all include wind)

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Background on Wind Energy in USTax incentives

• Federal Incentives:• Renewed incentives Feb 2009 through 12/31/12, via ARRA• 2.2 cents per kw-hr PTC for 10 yrs or 30% investment tax credit (ITC)

• State incentives:• IA: 1.5¢/kWhr for small wind, 1¢/kWhr for large wind• Various other including sales & property tax reductions

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College of EngineeringFederal energy policy (don’t have one)

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• In congress, “Energy bill” means Federal RPS, and “Climate bill” means CO2 emissions control.

• Waxman-Markey Energy/Climate bill passed house 6/09. Climate part was “Cap and Trade.”

• Related Kerry-Graham Climate bill did not pass Senate.• 2010 Carbon Limits & Energy For America’s Renewal, CLEAR

Act (Sen Collins/Cantwell), “Cap & Refund”• Cap CO2 “upstream” via sales of coal, gas, petroleum• Producers/importers buys CO2 permits in monthly auction• 3/4 of auction revenues refunded to US citizens

• Congressional attention died; Climate/energy bill non-issue in pres. campaigns

• 7/11 EPA rules “Cross-State Air Pollution Rule” (CSAPR, for SO2, NOx), “Mercury/Air Toxics Standards” (MATS) have more effect, causing near-term power plant shut-down, but CSAPR stayed on 12/30/11 by US Court of Appeals, DC Circuit.

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Background on Wind Energy in US

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Grand Challenge Question For Energy:

What investments should be made, how much, when, and where, at the national level, over the next 40 years, to achieve a sustainable, low cost, and resilient energy & transportation system?

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NUCLEAR

GEOTHERMALSOLAR

WindBIOMASS

CLEAN-FOSSIL

Where, when, how much of each, & how to interconnect?

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Grand Challenges For Wind:1. Move wind energy from

where it is harvested to where it can be used

2. Develop economically-attractive methods to accommodate increased variability and uncertainty introduced by large wind penetrations in operating the grid.

3. Improve wind turbine/farm economics (decrease investment and maintenance costs, increase operating revenues).

4. Address potential concerns about local siting, including wildlife, aesthetics, and impact on agriculture.

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Wind vs. people

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How to address grand challenges

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#1. Move wind energy from where it is harvested to where it can be used.• Transmission

• Eastern interconnection Midwest to East coast• National Superhighways at 765 kV AC and/or 600/800 kV DC

• Right of way (rail, interstate highwys, existing transmission)• Cost allocation• Organizational nightmare

• Conductor technologies: overhead/underground, materials• Offshore, lower CF turbines, higher turbines, but all of these result in higher cost of energy

College of EngineeringHow to address grand challenges

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NETPLAN: multiperiod, multiobjective, multisector

Investments mainly in renewables with some nuclear.

Flow is west to east.Highest trans cap investment is MAIN (4) to ECAR (1) because: •CF (0.5 in MAIN, 0.3 in ECAR)•Load is very high in ECARHigh trans cap investment from SPP (10) to STV (9) because:•CF (0.4 in SPP, 0.1 in STV)•Load is very high in STV

CPLEX LP inside evolutionary program; co-optimizes generation, transmission, gas pipelines to minimize 40 year investment+production costs, network flow.

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How to address grand challenges

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#2. Develop economically-attractive methods to accom-modate increased variability and uncertainty introduced by large wind penetrations in operating the grid.• Variability:

• Increase gas turbines• Wind turbine control• Load control• Storage (pumped hydro, compressed air, flywheels, batteries, others)• Increase geodiversity

• Uncertainty:• Decrease it: improve forecasting uncertainty• Handle it better: Develop UC decisions robust to wind pwr uncertainty

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How to address grand challenges

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#3. Improve wind turbine/farm economics (decrease investment/maint costs, increase operating revenues).• Investment: Improve manufacturing/supply chain processes, construction, collection circuit layout, interconnection cost, land lease, and financing• Operating & maintenance:

• Improve monitoring/evaluation for health assessment/prediction/life-ext• Decrease maintenance costs (gearbox vs. direct-drive)

• Enhance energy extraction from wind per unit land area• Improved turbine siting• Inter-turbine and inter-farm control• Increased efficiency of drive-train/generator/converters• Lighter, stronger materials and improved control of rotor blades• Taller turbines

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Wind turbine down-time distribution

Reference: McMillan and Ault, “Quantification of Condition Monitoring Benefit for Offshore Wind Turbines,” 2007.

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How to address grand challenges

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#4. Address potential concerns about local siting, including wildlife, visual/audible, impact on agriculture.• Migratory birds and bats: mainly a siting issue for birds. Bat-kill is more frequent.•Agriculture: Agronomists indicate wind turbines may help!• Visual: a sociological issue

These issues have not been significant yet. Today, in Iowa, there are ~2600 turbines, with capacity 4200 MW. At 2 MW/turbine, a growth to 60 GW would require 30000 turbines, and assuming turbines are located only on cropland having class 3 or better winds (about 1/6 of the state), this means these regions would see, on average, one turbine every 144 acres.