The Coming Power of Wind: Perspectives and Prospects
Soirée Technique, Dec 8th
Session 4: Renewable Energy SourcesPresented by Dr. Barry Rawn Delft University of Technology
Prospects:
long term price stability
Perspectives: policy makers and lawyers
major component of energy security
.. they are different.
..they are many. investors
electricity grid and market operators
This talk is about:substantial helpfuleffect on climate
re-think way we run power system
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substantial helpfuleffect on climate
European level:About 25-30% of efforts
Global: the “stabilization triangle”
Image credit: cmi.princeton.edu
200 Gt, in next 50 years:Each wedge: GT/year
Install 2TW of wind; provide about 5 PWh
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We’re coupling our energy system to climate patterns, and to weather patterns.
Image credit: The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001
Regional-but renewable
Variable,but predictable.
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Will climate change affect wind power projects?
Michelangeli and Loukos, 2007
Lorenz and DeWeaver, 2007
Rough reasoning anticipatesfuture reduction in yield…
..detailed models confirm.
Effect varies over globe; depends on local features; hard to predict.
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Will wind power projects causeclimate changes?
wind energy conversionrequires momentum transfer.
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Brand 2009
minimum safe distance (2-10% deficit): order of tens of kilometers
the recovery distance (1% Deficit): hundreds of kilometers.
Christiansen and Hasager 2005
Wake effect: becoming of legal interest
Will wind power projects causeclimate changes?
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Brand 2009
Change global mean temperature?
Wind power affects crops, local weather?
Detectable but negligible compared toanthropogenic forcing.
Keith, 2004
First indication: helpful or neutral; but research just starting
Takel, 2011
Will wind power projects causeclimate changes?
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Physical Potential
Technical Potential
Economic Potential
Is there even that much wind power?8
Hoogwijk 2004
Technical: 96 PWh/year, Economic: 53 PWh/year at 0.13 €/kWh
21 PWhr/year at 0.052 €/kWh
versus 15 PWh/year global electricity consumptionof global electricity consumption
Is there even that much wind power?9
Hoogwijk 2004
3 PWh/yearEuropean electricity consumption in 2008:
Is there even that much wind power?
Many regions have resource exceeding consumption, costs differ.
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Hoogwijk 2004
As of 2004, about 0.05% of the economic potential was developedAs of 2010: perhaps 0.4%.
How much has been built?
Global: 0.5T USD a year to meet 450 PPM (vs bond market 90 T USD)Europe: to meet EU targets, 30-65 billion a year (vs bond market 23 T, GDP of Europe: 16T)
Trend in pension fund investment in infrastructure: estimated at 1 T a year
Is there enough money to build it all?
Growth rate of last 5 years: ~27% (doubles every ~3 years)
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Source: GWEC
Addressing investment risk: significant deployment barrier
Sources of risk: resource uncertainty, inflation, construction delay
Mitigation instruments: wind derivatives, loan guarantees, construction insurance
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Samec 2011
Generation mix: limits and changes in thinking
Storage or transmission needed to avoid curtailment
30% renewable energy scenario studied in North America: (image credits NREL)
nuclear
coal
wind
Total system load:
Inflexible generation can impose minimum generation limit:
“Cycling” of units uncomfortable;Need emerges for new types
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Variability and Uncertainty
Wind power forecasts a common tool in control rooms.
Provision alwaysexisted for changes:both anticipatedand unexpected.
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Image credit:Makarov et al, PNNL-19189, 2010
Madsen and Pinson: imm.dtu.dk, 2009
Farm-level control using pitch
Wind speed(m/s)
Power production(MW)
0 minutes 2
“Soft Storm Transition” or “Storm Control”:
Image credit: Gijs van Kuik, TU Delft, DUWIND
Image credit:
upwind.eu
Image credit:
upwind.eu
Example:Denmark
First to pioneercontrollable wind power, because forecasts notperfect.
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Example:Denmark
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Image credit: Energinet
Switched Power Electronics Interfaces
Synchronous Machine (traditional)
simple, fixed, strongPower Electronic Interface
Complex, flexible,relatively fragile
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An island electric power system
Must be mostly self-sufficient, even for short periods
Hirvonen 2003
Example:Ireland
Contingency event:Loss of big generator,or introduction ofbig load
In first instances:Need to use energystored in system’srotating masses
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2008/2009 range ofoperation
60-70%Systemsplits in half, collapses.
70-80%System collapsesimmediately
Wind turbinerotors notforced to besynchronous: -> several related problems
Example:Ireland
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Eirgrid, All-Island TSO Facilitation of Renewables Studies, Final Study Report
Image credit: RED Eléctrica España
formerly allowed disconnect levelnew requirementtypical transient
Electricity grid behaviour during a fault (lightening, tree, etc)
generators can help by staying connected, in spite of voltage transient:
Example:Spain
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Bömer 2011
Example:Spain Wind power production behaviour *before* “ride-
through” requirement: nuclear sized dips.
How are the worst situations avoided?
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Image credit: RED Eléctrica España
!
Image credit: RED Eléctrica España
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We’re coupling our energy systemto the climate in a new way.
Generation is always a mixture; wind power plants their own animal offering challenges but also benefits
Wrapping up:
Variability and uncertainty in our power system: not a new thing, but changes can be expected
From all these perspectives,which ideas to take home ?
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