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

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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