Addressing Some Common Misconceptions Governors Wind Energy Coalition Transmission Briefing November 3 2011 Washington DC Ed DeMeo Renewable Energy Consulting Services Inc Technical Advisor ID: 340514
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Wind Power Integration and Transmission:Addressing Some Common Misconceptions
Governors Wind Energy Coalition Transmission Briefing
November 3, 2011 Washington, DC
Ed DeMeo
Renewable Energy Consulting Services, Inc.
Technical Advisor:
Governors Wind Energy Coalition(EPRI Renewable Energy Programs, 1976-1998)
eademeo@comcast.net
650 327 3090Slide2
Key Questions
What benefits are expected from wind power?
Will these benefits actually be realized?
Address common misconceptions in the context of these questionsSlide3
Expected Benefits
Affordable, plentiful, domestic energy
Clean energy; reduced fossil-fuel combustion and emissions
Substantial economic development opportunities nationwideReduced electric-sector water consumptionhttp://www.20percentwind.org Slide4
Affordable?
Common criticism: wind needs subsidies
But conventional energy has received substantial subsidies for years – nearly 100 for oil and gas
There is no Free Market in energy!
O&G, 91 yrs, $4.9 B/yr Wind, 15 yrs, $0.4 B/yrSlide5
Affordable?
Common criticism: wind’s variability and uncertainty require one-for-one backup and greatly increase power-system operating costs
Balance between demand and generation needs to be continually maintained
Wind’s variability and uncertainty complicates the balancing process over minutes, hours, days
But utilities are used to dealing with variability in demand
Wind’s challenge is one of degree, not kindSlide6
One-for-One Backup?
Does a megawatt of wind require a megawatt of conventional backup?Slide7
One-for-One Backup?
Does a megawatt of wind require a megawatt of conventional backup?
No power plant has dedicated backup
All plants work together to serve system demand for electric energyGeneration mix includes reserves to accommodate a wide range of potential contingencies (10-15%)Substantial wind increases the need for reserves, increasing operating costs
Incremental operating costs: integration costsSlide8
One-for-One Backup?
Does a megawatt of wind require a megawatt of conventional backup?
No power plant has dedicated backup
All plants work together to serve system demand for electric energyGeneration mix includes reserves to accommodate a wide range of potential contingencies (10-15%)Substantial wind increases the need for reserves, increasing operating costs
Incremental operating costs: integration costs
With over 40,000 MW of wind in the US, not 1 MW of backup generation has been added! Slide9
2003 through 2010: Many Wind Integration Studies Across the Nation
Examined larger and larger
regions
Wind energy contributions up to ~ 30%Key Result: Wind integration costs under ~10% of wholesale value (i.e., under ~ ½¢/kWh)Why? Aggregating wind over larger regions mitigates wind variability
Variability tends to average outWhy? Sharing reliability responsibilities over larger regions reduces operating costsSlide10
Large Balancing Areas Reduce Reserve Requirements
Approximate regulating requirements for a BA
as a function of peak demand.
Source:MN DOC
Peak load: 100 1,000 10,000 100,000
Regulation: 9 30 90 300Slide11
Operating strategies: e.g., reserves sharing; and generator dispatch decisions at 5-min intervals instead of hourly, enabling better use of forecasts
Regional connectivity: efficient transmission use and judicious transmission expansion
Demand response: automatic load shifting at critical times
Generating units designed for rapid changes in output levelAffordable system-level storage (most expensive source of flexibility – may not be needed)
Wind Integration Requires Power-System Flexibility
Terry Boston, CEO of PJM Interconnection on Demand Response:
“Traditionally, generation chases loads. Now we need to have load chase generation.” October 26, 2011Slide12
Benefits of Forecasting
Better decisions for day-ahead system planning
Better plant-dispatch decisions hour-to-hour and within the hourAdvance warning of major weather events
Forecasting accuracy good and improvingValue of current forecasts: ~1¢/kWh (NY study)Accuracy improves with aggregation
Wind Forecasting Reduces System-Operation CostsSlide13
Plentiful?
Common criticism: wind requires too much landSlide14
20% Wind: Area Comparisons
Rhode Island
1,045 mi
2
West Virginia
24,087 mi
2
Anchorage, AK
1,961 mi
2
305 GW of Wind Total Footprint*: 23,830 mi
2
Area Occupied by Turbines, Equipment, Roads**: 950 mi
2
*12.8 MW/mi
2
; **4% occupancy
Wind equipment occupies an area less than Rhode Island and less than half of Anchorage, AK Slide15
Plentiful?
Common criticism: wind requires too much land
For 20% US electricity from wind, about 1,000 mi
2
dedicated to wind equipment
Comparable to area occupied by US Interstate Highway System (about 1% of all roads)
For perspective, May 2011 Arizona wildfire burned 469,000 acres (~730 mi2)Wind area requirement criticized in June 2011 NY Times Op-Ed by Robert BryceGWC Chair and Co-chair rebutted; NYT ignoredSlide16
But Wind Needs Transmission
Allows access to the best wind resources
Allows pooling of wind plant outputs over wide regions, smoothing variability and reducing integration costs
Allows sharing of reliability responsibilities over wider regions, reducing costs
Provides broad reliability and economic benefits to all in the regionSlide17
But Wind Needs Transmission
Common criticism: transmission is too expensive
Eastern concern: transmission from Midwest will increase coal generation transport to the East
Allows access to the best wind resources
Allows pooling of wind plant outputs over wide regions, smoothing variability and reducing integration costs
Allows sharing of reliability responsibilities over wider regions, reducing costs
Provides broad reliability and economic benefits to all in the regionSlide18
LARGE TRANSMISSION INVESTMENTS HAVE VERY SMALL RETAIL BILL IMPACTS
Average Monthly Retail Bill $ / 1,000 kWhs
Total $65.75
Total $66.62
Transmission 6%
Generation 74%
Distribution 20%
Impact from $12.6 billion increase (20%) in Transmission Infrastructure
Source:
FERC
~ 2001Slide19
Eastern Wind Integration and Transmission Study
Substantial transmission added in all four scenarios, but coal generation nearly same in the three 20% scenarios
Scenarios
1) Best wind, Midwest primarily, no off-shore
(20% wind)
2) Some off-shore, less Midwest (20% wind)
3) Aggressive off-shore (20% wind)4) Aggressive on- and off-shore (30% wind)Slide20
Does Wind Power Really Reduce Emissions?
Ramping of fossil plants introduces inefficiencies
Providing reserves from fossil plants also introduces inefficiencies
Some have claimed that the inefficiencies would cancel out any expected wind emissions benefitsBentek, LLC originally claimed this but has revised their work and retracted the claimBut naysayers continue to perpetuate this myth
The press seems to love the controversy and gives the naysayers airtimeSlide21
Stylized Illustration: 100 MW Fossil Plant Providing +/-10 MW Reserves
Plant efficiency reduced slightly when power deviates 10 MW from rated levelSlide22
Careful studies to date indicate actual emissions reductions will be 90-to-95% of ideal reductions
More thorough evaluations are underway
Does Wind Power Really Reduce Emissions?
“The study implies that small, short-term emission increases associated with ramping result in significant increases in the total emissions. This is simply wrong. Since 2007, we have added hundreds of megawatts of wind generation, and our overall emissions have declined. In 2009, wind produced 10 percent of the energy delivered to our customers. Without wind, that electricity would have been generated by gas or coal, creating greater total emissions.”
Frank Prager, VP Environmental Policy, Xcel Energy
Denver Post, May 28, 2010Slide23
Does Wind Power Really Reduce Emissions?
20% Wind Evaluation estimates flat-lined CO
2
emissions from the electric sector
Substantial wedge of needed reduction
Climate-change deniers doubt the earth is warming; Berkeley Earth Surface Temperature study – carried out by skeptics – has crushed this mythSlide24
Significant Water Use Savings Cumulatively, the 20% Wind Scenario would avoid the consumption of 4 trillion gallons of water
through 2030.
The 20% Wind Scenario cuts electric sector water consumption by 17% in 2030
.
Extraction of shale gas and tar-sands oil requires large amounts of waterSlide25
Xcel Energy Today: Minnesota and Colorado
Wind now
exceeds 10
% of retail energy generationRevising previously approved system expansion plans – with PUC approvalReplacing planned coal plants with wind and gas plants; emissions and costs are key factors driving this strategyLearning how to deal with wind’s natural characteristics
Actual utility experience is the strongest response to those who perpetuate the myths!Slide26
Summary
Wind energy is affordable now
Integration costs are minor; increased power-system flexibility and wind forecasting will reduce them
Wind tax incentives help to compensate for existing subsidies for conventional energyTransmission is affordable and provides broad benefitsWind reduces emissions of pollutants and greenhouse gases and saves water
Utilities are relying on wind for substantial and growing portions of their generation portfolioSlide27
www.uwig.org
Wind Integration State of the Art:
IEEE Power & Energy Magazines
November-December 2005, 2007, 2009, 2011Slide28
References
U.S. Department of Energy. 2008.
20% Wind Energy by 2030. DOE/GO-102008-2567. Washington, DC. Available at http://www.20percentwind.org
Pfund and Healey. 2011. What Would Jefferson Do? The Historical Role of Federal Subsidies in Shaping America’s Energy Future. DBL Investors. Available at http://www.dblinvestors.com/documents/What-Would-Jefferson-Do-_Final_September2011.pdfHand et al. 2008. Power System Modeling of 20% Wind-Generated Electricity by 2030.
National Renewable Energy Laboratory. Conference Paper NREL/CP-500-42794. Golden, CO. Available at http://www.nrel.gov/docs/fy08osti/42794.pdf
National Renewable Energy Laboratory. 2010. Eastern Wind Integration and Transmission Study. NREL/SR-550-47078. Golden, Colorado. Available at http://www.nrel.gov/wind/systemsintegration/ewits.html
Berkeley Earth Temperature Study. Available at http://berkeleyearth.org/