Sustainable Energy - without the hot air

383 Pages·2009·4.62 MB·english

by  David JC MacKay

Thequest for safe, secure and sustainable energy poses one Thisisareallyvaluablecontributiontothecontinuingdis-
of the most critical challenges of our age. But how much cussion ofenergy policy. Theauthoruses a potent mixture
energy do we need, and can we get it all from renewable of arithmetic and common sense to dispel some myths and
sources? DavidMacKaysetsouttofindtheanswerthrough slay some sacred cows. The book is an essential reference
a forensic numerical analysis of what we use and what we workforanyonewithaninterestinenergywhoreallywants
can produce. His conclusions starkly reveal the difficult tounderstandthenumbers.
choicesthatmusturgentlybetakenandreadersinterestedin
LordOxburghKBEFRS
howwewillpoweroursocietyinthefuturewillfindthisan Former Chairman,RoyalDutchShell
illuminatingread. Foranyonewithinfluenceonenergypol-
icy,whetheringovernment,businessoracampaigngroup, This is a brilliant book that is both a racy read and hugely
this book should be compulsory reading. This is a techni- informative.
cally precise and readable account of the challenges ahead.
ProfDavidNewberyFBA
It will be a core reference on my shelf for many years to
come.
So much uninformed rhetoric is thrown about on climate
TonyJuniper changeand energysystemsthatthereisanurgent needfor
FormerExecutiveDirector,FriendsoftheEarth an authoritative study setting out just what can and can-
notrealisticallybedonetoachievesustainableenergy. This
Engagingly written, packed with useful information, and hugely important book fills that gap both technically and
refreshinglyfactual. highlyreadably. Itshouldbea‘mustread’notonlyathome
PeterAinsworthMP and in industry, but on each Government Minister’s desk,
ShadowSecretaryofState andnotjustintheUK.
forEnvironment, Food, andRuralAffairs MichaelMeacherMP
FormerEnvironment Minister
DavidMacKaysetsouttodispelthehalftruths,distortions
and nonsense which make up so much of what we’re told DavidMacKay’sbooksetsthestandardforallfuturedebate
about climate change and our energy needs. This book is onenergy policy and climatechange. His dedicationto the
readable, accessible and thorough. He cuts through un- facts and to rational argument is admirable in a field beset
founded opinion and takes us to facts and figures which bypropagandaandwishfulthinkingonallsides,andevenif
speak for themselves. It’s a useful guide for both layman hisconclusionseventuallydate,asallscientificworkmust,
andexpert. Iheartilyrecommendit. hisapproachwillliveonforaverylongtime.
GrahamStuartMP DavidHowarthMP
Thisremarkablebookfromanexpertintheenergyfieldsets The choices that we make (or fail to make) in the coming
out, with enormous clarity and objectivity, the various al- years about sustainable energy will determine what world
ternative low-carbon pathways that are open to us. Pol- future generations will inherit. How do we arrive at ratio-
icymakers, researchers, privatesectordecisionmakers, and nal decisions? In his book, David MacKay does not tell us
NGOs,allwillbenefitfromthesewordsofwisdom. what to choosebut how to. Basic arithmetic is all it takes
SirDavidKingFRS to distinguish between viable strategies and pipedreams.
ChiefScientificAdviser Anybody who feels responsible for the future of our society
totheUKGovernment, 2000–08 shouldreadthisbook.
ProfDaanFrenkelFRS
Startedreadingyourbook yesterday. Tookthedayoffwork
today so that I could continue reading it. It is a fabulous, Atotaldelighttoread. Extraordinarilyclearandengaging.
witty, no-nonsense, valuable piece of work, and I am busy
ChrisGoodall
sendingittoeveryoneIknow.
AuthorofTenTechnologiestoSavethePlanet
MatthewSullivan
CarbonAdviceGroupPlc
continuedonnextpage
DavidMacKay’sbookisanintellectuallysatisfying,refresh- At last a book that comprehensively reveals the true facts
ingcontributiontoreallyunderstandingthecomplexissues aboutsustainableenergyinaformthatisbothhighlyread-
of energy supply and use. It debunks the emotional clap- ableandentertaining. A“mustread”forallthosewhohave
trap which passes for energy policy and puts real numbers aparttoplayinaddressingourclimatecrisis.
intotheequations. Itshouldbereadbyeveryone,especially
RobertSansom
politicians.
DirectorofStrategyandSustainableDevelopment
Prof IanFellsCBE EDFEnergy
FounderchairmanofNaREC,
theNewandRenewableEnergyCentre So much has been written about meeting future energy
needs that it hardly seems possible to add anything use-
Preventingclimatechaoswillrequiresophisticatedandwell ful, but DavidMacKay has managed it. His new book is a
informed social, economic and technological choices. Eco- delighttoreadandwillappealespeciallytopracticalpeople
nomicandsocial‘laws’arenotimmutable–politicianscan who want to understand what is important in energy and
and should reshape economics to deliver renewable energy whatisnot. LikeLordKelvinbeforehim,ProfessorMacKay
and lead cultural change to save energy – but MacKay re- realisesthatinmanyfields, andcertainlyinenergy,unless
mindsusthateventhey“cannachangethelawsofphysics”! youcanquantify somethingyoucanneverproperlyunder-
MacKay’s book alone doesn’t have all the answers, but it stand it. As a result, his fascinating book is also a mine of
provides a solid foundation to help us make well-informed quantitativeinformationforthoseofuswhosometimestalk
choices,asindividualsandmoreimportantlyassocieties. to our friends about how we supply and use energy, now
andinthefuture.
DuncanMcLaren
ChiefExecutive,FriendsoftheEarthScotland DrDerekPooleyCBE
Former ChiefScientistattheDepartmentofEnergy,
MacKay brings a welcome dose of common sense into the ChiefExecutiveofthe UKAtomicEnergyAuthority
discussion of energy sources and use. Fresh air replacing andMemberoftheEuropeanUnionAdvisoryGroup
hotair. onEnergy
ProfMikeAshbyFRS
AuthorofMaterialsandtheenvironment The need to reduce our dependence on fossil fuels and to
find sustainable sources of energy is desperate. But much
Byfocusingonthemetricsofenergyconsumptionandpro- ofthediscussionhasnotbeenbasedondataonhowenergy
duction,inadditiontotheaspirationweallshareforviable is consumed and how it is produced. This book fills that
renewable energy, David MacKay’s book provides a wel- need in an accessible form, and a copy should be in every
comeadditiontotheenergyliterature. “SustainableEnergy household.
– without the hot air” is a vast undertaking that provides Prof RobertHindeCBEFRSFBA
bothapracticalguideandareferencemanual. Perhapsiron- ExecutiveCommittee, PugwashUK
icallyforabookonsustainableenergy,MacKay’saccountof
thenumbers illustrates just how challenging replacing fos- What a lovely book ... I feel better in a way that a cancer
silfuelwillbe, and whybothenergy conservationandnew patient might feel after reading something in-depth about
energytechnologyarenecessary. hisdisease.
DarranMessem RichardProcter
Vice PresidentFuelDevelopment
RoyalDutchShell Beautifullyclearandamazinglyreadable.
Prof WillyBrownCBE
This is a must read for anyone who wants to help heal our
world. Itookittothelooandalmostdidn’tcomeoutagain.
CarolAtkinson MatthewMoss
ChiefExecutiveofBREGlobal
Sustainable Energy — without the hot air

Sustainable Energy — without the hot air
David JC MacKay
UIT
CAMBRIDGE, ENGLAND
FirstpublishedinEnglandin2009.
UITCambridgeLtd.
POBox145
Cambridge
CB41GQ
England
Tel: [phone]
Web: www.uit.co.uk
Copyright©2009DavidJCMacKay
Allrightsreserved.
ISBN978-0-9544529-3-3 (paperback)
ISBN978-1-906860-01-1 (hardback)
TherightofDavidJCMacKaytobeidentifiedas
theauthorofthisworkhasbeenassertedbyhim
inaccordancewiththeCopyright,Designsand
PatentsAct1988.
Whilethispublicationintendstoprovide
accurateandauthoritativeinformationinregard
tothesubjectmattercovered,neitherthe
publishernortheauthormakesany
representation,expressorimplied,withregard
totheaccuracyofinformationcontainedinthis
book,nordotheyacceptanylegalresponsibility
orliabilityforanyerrorsoromissionsthatmay
bemade. Thisworkissuppliedwiththe
understandingthatUITCambridgeLtdandits
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attemptingtorenderengineeringorother
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acknowledgestrademarksasthepropertyof
theirrespectiveowners.
10987654321
3.5.2
to those who will not have the benefit
of two billion years’ accumulated energy reserves
Preface
What’s this book about?
I’m concerned about cutting UK emissions of twaddle – twaddle about
sustainableenergy. Everyonesaysgettingofffossilfuelsisimportant,and
we’re all encouraged to “make a difference,” but many of the things that
allegedlymakeadifferencedon’taddup.
Twaddle emissions are high at the moment because people get emo-
tional (for example about wind farms or nuclear power) and no-one talks
aboutnumbers. Oriftheydomentionnumbers,theyselectthemtosound
big, to make animpression, and to score points in arguments, rather than
toaidthoughtfuldiscussion.
This is a straight-talking book about the numbers. The aimis to guide
thereaderaroundtheclaptraptoactionsthatreallymakeadifferenceand
topoliciesthataddup.
This is a free book
Ididn’twrite this book tomake money. I wrote itbecausesustainable en-
ergyisimportant. Ifyouwouldliketohavethebookforfreeforyourown
use,pleasehelpyourself: it’sontheinternetatwww.withouthotair.com.
Thisisafreebookinasecondsense: youarefreetouseallthematerial
inthis book, exceptfor the cartoons andthe photos with anamed photog-
rapher,undertheCreativeCommonsAttribution-Non-Commercial-Share-
Alike 2.0 UK: England & Wales Licence. (The cartoons and photos are
exceptedbecausethe authors havegenerally givenme permission only to
includetheirwork,nottoshareitunderaCreativeCommonslicense.) You
areespeciallywelcome to use my materialsfor educationalpurposes. My
website includes separate high-quality files for each of the figures in the
book.
viii
How to operate this book
Somechaptersbeginwithaquotation. Pleasedon’tassumethatmyquot-
ingsomeonemeansthatIagreewiththem;thinkofthesequotesasprovo-
cations,ashypothesestobecriticallyassessed.
Manyoftheearlychapters(numbered1,2,3,...) havelongertechnical
chapters(A,B,C,...) associatedwiththem. Thesetechnicalchaptersstart
onpage254.
At the end of each chapter are further notes and pointers to sources
andreferences. Ifindfootnotemarksdistractingiftheylitterthemaintext
ofthebook,sothebookhasnofootnotemarks. Ifyoulovefootnotemarks,
youcanusefullyaddthem–almosteverysubstantiveassertioninthetext
will have an associated note at the end of its chapter giving sources or
furtherinformation.
The text also contains pointers to web resources. When a web-pointer
ismonstrously long, I’veusedthe TinyURL service, andputthe tinycode
in the text like this – [yh8xse] – and the full pointer at the end of the
book on page 344. yh8xse is a shorthand for a tiny URL, in this case:
http://tinyurl.com/yh8xse. A complete list of all the URLs in this book is
providedathttp://tinyurl.com/yh8xse.
Iwelcomefeedbackandcorrections. IamawarethatIsometimesmake
booboos, and in earlier drafts of this book some of my numbers were off
by a factor of two. While I hope that the errors that remain are smaller
thanthat,IexpecttofurtherupdatesomeofthenumbersinthisbookasI
continue tolearnaboutsustainableenergy.
Howtocitethisbook:
DavidJ.C.MacKay. SustainableEnergy–withoutthehotair.
UITCambridge,2008. ISBN978-0-9544529-3-3. Availablefreeonline
fromwww.withouthotair.com.
ix
Contents
I Numbers, not adjectives . . . . . . . . . . . . . . . . . 1
1 Motivations . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2 Thebalancesheet . . . . . . . . . . . . . . . . . . . . . . 22
3 Cars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4 Wind . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
5 Planes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6 Solar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7 Heatingandcooling . . . . . . . . . . . . . . . . . . . . . 50
8 Hydroelectricity . . . . . . . . . . . . . . . . . . . . . . . 55
9 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
10 Offshorewind . . . . . . . . . . . . . . . . . . . . . . . . 60
11 Gadgets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
12 Wave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
13 Food andfarming . . . . . . . . . . . . . . . . . . . . . . 76
14 Tide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
15 Stuff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
16 Geothermal . . . . . . . . . . . . . . . . . . . . . . . . . . 96
17 Public services . . . . . . . . . . . . . . . . . . . . . . . . 100
18 Canweliveonrenewables? . . . . . . . . . . . . . . . . 103
II Making a difference . . . . . . . . . . . . . . . . . . . . 113
19 EveryBIGhelps . . . . . . . . . . . . . . . . . . . . . . . 114
20 Bettertransport . . . . . . . . . . . . . . . . . . . . . . . 118
21 Smarterheating . . . . . . . . . . . . . . . . . . . . . . . 140
22 Efficientelectricityuse . . . . . . . . . . . . . . . . . . . 155
23 Sustainablefossilfuels? . . . . . . . . . . . . . . . . . . . 157
24 Nuclear? . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
25 Livingonother countries’renewables? . . . . . . . . . . 177
26 Fluctuationsandstorage . . . . . . . . . . . . . . . . . . 186
27 FiveenergyplansforBritain . . . . . . . . . . . . . . . . 203
28 Puttingcostsinperspective . . . . . . . . . . . . . . . . 214
29 Whattodonow . . . . . . . . . . . . . . . . . . . . . . . 222
30 EnergyplansforEurope,America,andtheWorld . . . 231
31 Thelastthingweshould talkabout . . . . . . . . . . . . 240
32 Sayingyes . . . . . . . . . . . . . . . . . . . . . . . . . . 250