Plans for Solar Cookers 58 Pages

Solar Cookers Internationalspreadingsolarcookingtobenefit

peopleandenvironments

How to make,

use and enjoyHow to make,

use and enjoyHow to make,

10use and enjoy10use and enjoy

thuse and enjoy

thuse and enjoy

editionuse and enjoy

editionuse and enjoy

SOLARCOOKERSHowtomake,useandenjoy

10thEdition,2004

Thisguidebookisasumofcontributionsfromeducators,engineers,long-timesolarcooksandpromoters,mostofwhoservedasvolunteerswithSolarCookersInternational(SCI).SpecialthankstoMarkAalfs,PaulBarth,ElinorBenes,RogerBernard,RickBlodgett,BarbaraBlum,BevBlum,GeorgiannaBorgens,JayCampbell,DonCoan,SherryCole,RamónCoyle,MariaGonzalez,GerrideGraaf,TomJuring,BarbaraKerr,BarbaraKnudson,BethLuna,DaveMaize,PaulMellersh,BobMetcalf,JohnMurphy,FaustineOdaba,JoeOn,MargaretOwino,EdPejack,KevinPorter,MarkRothman,LouiseSeeley,ClarkandEleanorShimeall,RandySmithandKimVictorine.ThiseditionreceivedsupportfromtheRichardandRhodaGoldmanFundandtheSacramentoAreaEarthDayNetwork.PasteditionsofthisbookletweresupportedbytheAmericanConservationAssociation,theEducationalFoundationandtheW.AltonJonesFoundation.

SolarCookersInternationalisa501(c)(3)nonprofit,nongovernmentalorganizationspreadingsolarcookingtobenefitpeopleandenvironments.

SolarCookersInternational

191921stStreet,Suite101Sacramento,California95814-6827

UnitedStatesofAmerica

Tel:+1(916)455-4499Fax:+1(916)455-4498

[email protected]

CONTENTS

IntroductionWhysolarcook? 3Issolarcookingforyou? 4

SolarcookerconceptsTypesofsolarcookers 6Howsolarcookerswork 7Frequentlyaskedquestions 8

HowtomakeandusesolarcookersModel1:Panelcooker(theCooKit) 12Model2:Boxcooker 18Substitutematerials 26

SolarrecipesandtipsGrains,Pasta 31Legumes 32Meats 33Vegetables 34Fruit 35Breads,Bakedgoods 36Otherfoods 37Quicktreats 38

AlternativesolarcookerusesSolarpasteurization 40Otheruses 42

IdeasforteachersQuickiedemoCooKit 44Solaractivities 45

AbriefhistoryofsolarcookingAbriefhistoryofsolarcooking 52

SECTION1INTRODUCTION

2

SOLAR COOKERS How to make, use and enjoy

Whatexactlyisasolarcooker?Itisadevicethatallowsyoutocook

foodusingthesun’senergyasfuel.Isitreallypossibletocookwiththesun?Yes,andthisbookletwillshowyouhow.Itwillwalkyouthroughtheprocessofbuildingasimplesolarcooker,usingthecooker,andteachingsimplesolarcookingconceptstoothers.

Fromthebeginningoftime—andstillformanytoday—dailycookinghasrequiredfire,fuelgatheringandfrequentattentiontobesurefoodscookevenly,don’tburnanddon’tsticktothepot.

Dependingonwhereyouliveandhowyoucook,solarcookingcansaveyoutime,workandfuel.Andit’senvironmentallybenign.Allfoodscanbecookedinsometypeofsolarcooker.Thisbookletcoverslow-tomedium-temperaturesolarboxcookersandsolarpanelcookers(“CooKits”)thatslowlyandgentlycookallthefoodsyouboil,roastorbake.Othertypesofsolarcookersreachhightemperaturescapableoffrying.

Slowcookingisdifferent,butthedifferencesarenice.Slowcookingretainsflavor,moistureandnutrients,andmakesmeatstender.Recentstudiesindicatethatfoodscookedatmoderatetemperaturesmaybehealthier.

Whensolarcooking,addapproximatelyonehourtonormalcooktimes.Noneedtowatch,stirorworryaboutfood.Thecookspendsjusttwominutes:onetoputfoodinandonetotakefoodout.Formanyofus,solarcookinghasbecomeourfavoritewaytocook.

Solarcookerscomplementtraditionalcookingmethods,whicharestillusedatnightandduringinclementweather.

Thisbookletincludessolarcookingconcepts,solarcookerconstructionplansanddirectionsforuse,recipes,studentactivitiesandexamplesofnon-cookingusesofsolarcookers

includingsolarwaterpasteurization—abasicsurvivalskill.

Solarcookingcanmakeaworldofdifferenceifweeachuseitonsunnydaysandsharethisinformationwithothers.SCIdependsonthesupportofitsmembersanddonorstocontinuetobringthislife-savingknowledgetomillionsoffamiliesinfuel-scarce,sun-richpartsoftheworld.Weinviteyoutojoinusinthiseffort.

Bonappétit!

SOLAR COOKERS INTERNATIONAL

3

WHYSOLARCOOK?

Solarcookerssavemoneyandtime

✔Sunshineisfree.Solarcookingsavespreciousfuelforevenings,cloudydaysandcoldweather.

✔Foodscookunattendedwhileyoudootherthings.

✔Potsareeasytoclean.Fooddoesn’tstickontheinsideandthere’snosootontheoutside.

✔Asolarcookeriseasytomakefromavarietyofmaterials.

Solarcookersaresafe,healthyandconvenient

✔Thereisnofiretocauseburnsorblowoutofcontrol.

✔Thereisnosmoketoinjureeyesandcauselungproblems.Peopleallergictosmokecannowenjoy“solarcues”—barbecueswithoutthesmoke.

✔Mostsolarcookerscookat82-121ºC(180-250ºF),idealforretainingnutrients,moistureandflavorandnotburningfoods.Woodandgasfiretemperatures,bycontrast,exceed260ºC(500ºF).

✔Youcanbake,boilandlightlyfryfoodsintheirownjuices.Meatsgetverytender.

✔Solarwaterpasteurizationisaskilleveryoneshouldknowforemergencies.

✔Whensolarcooking,yourkitchenstayscoolonhot,sunnydays.

✔ACooKitfoldsforeasystorageorcarryingformealsawayfromhome.

Solarcookersareversatileandadaptable

✔Thesimpletechnologyiseasilyadaptedtoawidevarietyofconstructionmaterials,cookingcustomsandclimates.

Solarcookersarelife-savingdevicesforthoseinsunny,fuel-scarceregions

✔Solarcookershelptwooftheworld’spressingproblems—growingshortagesofcookingfuelsandthescourgeofwaterbornediseases.Halftheworld’spopulationcooksoverwoodfires.AccordingtotheUnitedNations,aboutone-thirdofus—twobillionpeople—nowsufferfuelwoodshortages.Women,andsometimeschildren,mustcarryfuelfurtherdistances,andspendmoretimedoingso,thaninthepast.Someurbanfamiliesspend30-50%oftheirincomeon

4


cookingfuelormustbarterawayfoodforfueltocooktheremainder.Familiesdropthenutritiousfoodsthatrequirelengthycooking—suchaslegumes—fromtheirdiet,contributingtomalnutrition.Manygovernmentsimportandsubsidizefossilfuels.Withsolarcookersfamiliesoftenreducefuelwoodneedsbyhalf.

✔PasteurizingwaterandmilkinsolarcookerscanhelpreduceCholeraandotherwaterbornediseases,whichkill50,000peopleeveryday.TheWorldHealthOrganizationestimates80%ofallillnessesarespreadthroughcontaminatedwater.

Solarcookerssavetreesandsoil

Indeforestedareas,effortstoprotectscarcetreesfailwhenpeoplehavenoalternativestowood-fueledcooking.AsagovernmentadministratorinZimbabwesaid,“Whentreesaregone,thenfollowserosionofthesoil....Thefarmerisunabletousetheland....Thesoiliswashedintotheriver.Waterneededforirrigationisnolongerthere.Thencottonandwheataremoreexpensive....Thisisacirclewithoutend.”

✔Eachsolarcookerinsunny,aridclimatescansaveonetonofwoodperyear.

Solarcookershelpairquality

✔Burningtraditionalfuelssuchaswoodandgaspollutestheairandcontributestoglobalwarming.Solarcookersprovideapollution-freealternative.

Achecklist

❑Doyouhavemostly-sunnydaysseveralmonthsoftheyear?(Essential)

❑Doyouhaveaspaceoutsidethatissunnyforseveralhours,shelteredfromhighwindandsafefromtheftortampering?

❑Areyourcookingfuelsexpensiveorscarce?

❑Doesyourkitchensometimesgettoohotoryourbarbecuetoosmoky?

❑Doyouworryaboutsafetyofsmallchildrennearyourkitchenstoveoropencookingfire?

❑Doyouwanttoprepareforemergenciesorcampingwhenyoumaynothavesafedrinkingwater?

❑Wouldyoulikecarefree,absenteecooking?

Ifyoucheckedseveralboxes,you’llprobablylikesolarcooking!

ISSOL

ARC

OOKI

NGFOR

YOU

?

SECTION2SOLARCOOKERCONCEPTS

6


Therearemanytypesofsolarcookers—heat-trapboxes,curvedconcentratorsandcombinationsofboth.

Boxcookers

Boxcookersarethemostwidelyusedinhouseholds.ThereareseveralhundredthousandinIndiaalone.

TYPE

SOF

SOL

ARC

OOKE

RS

Curvedconcentratorcookers

Curvedconcentrators(oftencalledparaboliccookers)cookfastatveryhightemperatureslikefire,butrequiremorefrequentadjustmentandsupervisionforsafeoperation.Theyarenotcoveredinthisbooklet,butseveralhundredthousandhouseholdsinwesternChinausethem.Theyareespeciallyusefulforlarge-scaleinstitutionalcooking.

Combinationcookers

Combinationcookers(oftencalledpanelcookers)incorporateelementsofboxandcurvedconcentratorcookers.SCI’ssimple“CooKit”isthemostwidelyusedcombinationcooker.

Comparedtocurvedconcentratorcookers:

•itdoesn’tneedtobemovedtotrackthesunduringseveralhoursofunattendedcooking

•temperaturesaremoreeven

•theflatshinysurfacesaresaferforyoureyes

Comparedtoaboxcooker:

•itrequiresnowindoworinsulation

•itcooksjustonepotatatime,butseveralunitscostlessthanoneboxcooker

Comparedtoboth:

•itiseasierandcheapertoproduce

•itfoldscompactlytocarryandstore

•itrequires10-20clear,heat-resistantplasticcookingbagsperyear


7

Fuel:sunlight

Sunlightisthefuel.Asolarcookerneedsanoutdoorspotthatissunnyforseveralhoursandprotectedfromstrongwind,andwherefoodwillbesafe.Solarcookersdon’tworkatnightoroncloudydays.

Convertsunlighttoheatenergy

Darksurfacesgetveryhotinsunlight,whereaslightsurfacesdon’t.Foodcooksbestindark,shallow,thinmetalpotswithdark,tight-fittinglidstoholdinheatandmoisture.

Retainheat

Atransparentheattraparoundthedarkpotletsinsunlight,butkeepsintheheat.Thisisaclear,heat-resistantplasticbagorlargeinvertedglassbowl(panelcookers)oraninsulatedboxwithaglassorplasticwindow(boxcookers).

Captureextrasunlight

Oneormoreshinysurfacesreflectextrasunlightontothepot,increasingitsheatpotential.

HOWSOLARCOOKERSW

ORK

8


FREQ

UENT

LYA

SKED

QUE

STIO

NS WhatcanIcook?

Useyoursolarcookertocookvegetables,fruits,meats,grains,legumesandmostotherfoods.Youcanevenbakebreadsanddesserts!Simplesolarcookerscannotstir-fryorcookflatbreadsthatrequirehightemperatures.

DoIneedtoaddwatertofoodsthatwillbesolarcooked?

Vegetables,fruitsandmeatscookgreatwithoutwater,whichtendstoslowcookingandwashawaynutrients.Forgrainsandlegumes,usetheamountofwateryouusewithothercookingmethods.Ifthefoodcomesouttoomoistordry,adjusttheamountofwaternexttime.

WhattimeofyearcanIcook?

Ingeneral,youcanuseyourcookerwhenthelengthofyourshadowonthegroundisshorterthanyourheight.Thisisanindicatorthatthesunishighenoughintheskytocook.Inmanycountriesthereareafewmonthseachyearwhensimplesolarcookerscannotbeused.Peoplelivinginthedarkerareasonthefollowingmaptendtohavelongercookingseasons.

WhattimeofdaycanIcook?

Youcantypicallycooktwomealsperday—anoontimemealandaneveningmeal.Youcannotcookearlyinthemorningoraftersunset.Thesunismostintensebetween10:00a.m.and2:00p.m.,whichiswhenbreads,cakesandpastriesshouldbebakedifpossible.

FastercookingSlowercookingNocookingFastercookingSlowercookingNocooking


9

Howlongdofoodstaketocook?

Therearemanyfactorsthataffectthespeedwithwhichyourfoodcooksinasolarcooker,includingtimeofyear,amountofsun,typeofpotandamountoffood.Thefollowingtablesummarizessomeimportantfactors.

Fastercooking Slowercooking

Timeofyearandday:

Amountofsun:

Amountofwind:

Thicknessofpot:

Amountandsizeoffood:

Amountofwater:

10


Simplesolarcookers,undernormalconditions,willcookattemperaturesfrom82-121°C(180-250°F)ormore.Sincefoodcooksat82-91ºC(180-195ºF)thesetemperaturesarehotenoughtofullycookfood,butnotsohotastoburnordryoutfoodordamagehealthfulnutrients.Also,manyfoodscancookforseveralhourswithoutovercooking,whichallowsfoodtobeplacedinthecookerearlyinthedayandleftuntilmealtimewithoutneedingtobestirredormonitored.(“Absenteecooking.”)

Aswithanycookingmethod,cookedfoodthatisallowedtocooltotemperatures

between52-10ºC(125-50ºF)foraperiodoftimemaycontainbacteriathatcanspoilfoodandleadtofoodpoisoning.Foodthatstaysinthistemperaturerangeformorethanfourhoursshouldbediscarded.

Herearesometypicalcookingtimesfor4pounds(2kilograms)offoodonasunnyday:

71�C Food pasteurization65�C Water pasteurization

49�C Most germscan't grow

22�C Room temperature

100�C Water boils

135�C

82�C Food Cooks

275757 �F

212�F

160�F150�F

180�F

120�F

72�F

Simple Solar Cookers

1-2 hours 5-8 hours3-4 hours

SECTION3HOWTOMAKEANDUSESOLARCOOKERS

12


MOD

EL1:

PAN

ELC

OOKE

R(C

OOKI

T)

TheCooKitisasimple,portablesolarcooker.Itcanbemadeinonetotwohoursandcancookonelargepotoffoodforaboutsixpeople.Forlargerfamilies,makealargerCooKitorseveralthissize.

Constructionmaterials

•Corrugatedcardboard(cartonboard)—0.9x1.2meters(3x4feet)

•Aluminumfoil—0.3x3meters(1x10feet),cutintostripsasneeded

•Glue(nontoxic,water-based,diluted1:1withwater)

•Paintbrush(thefoamtypeworkwell)

•Utilityknifeorsimilarcuttingdevice

•Pencil,penorothermarkingdevice

•Largerulerorotherstraightedge

•Seepage26forsubstitutematerials

Constructionsteps

1.Drawcutandfoldlinesoncardboardasindicatedbelow.

76�

90�

97�

60�

1122""//3300cmm

1122""//3300cm1122""//3300cm

88""//2200cmm

224""//6600cmm3366""//9900cm

4488""//112200cmm

888"""///222000cm

3366""//9900cmm111111"""///222888cmmm

111111"""///222888cm

111222"""///333000cm

13"/32cm

77.55""//1199cm

narrow slot, width ofcardboard thickness(about 1/8"/0.3cm)

13"/32cm

55""//11333cm

8"/20cm

1112""//33000cm

110"/255cm110.5"/2266cm

cut lines fofof ld lines optional fofof ld lines fofof r compact storage


13

2.CutouttheCooKitshapeandslots.

CutouttheCooKitshapeandthetwo60ºangledslotsinthefrontpanel.Besuretomaketheslotsnarrowsothe76ºangledcornersfromthebackpanelfitsnuglytoholdupthefrontpanel.(Refertostep3,page14.)

3.Scorethefoldlines.

Withabluntedge,suchasaspoonhandle,scorethefoldlines.Makestraightfoldsbyfoldingagainstafirmstraightedge.OnlyscoretheoptionalfoldlinesifyouintendtofoldtheCooKitforcompactstorage.(Seepage17.)

4.GluefoilonCooKit.

Usingapaintbrush,spreadtheglue/watermixtureonthedullsideofaluminumfoilandpressthegluedsheetsofaluminumfoiltightlyandsmoothlylikewallpaperontooneentiresideoftheCooKit.Afewwrinkleswon’thurt.

5.Leaveflatuntildry.Trimanyexcessfoil.

Cookingdirections

1.Putfoodinadarkpotwithadark,tight-fittinglid.

2.Enclosepotinatransparentheattrap.

Putthepotinaclear,heat-resistantplasticbagandbindtheopenendofthebagorsimplyfolditunderthepotinsuchawayastopreventairfromescaping.Thebagshouldbelooseenoughthatasmall,insulatinglayerofairexistsaroundthepot.

14


Optional:Cookingefficiencymaybemarginallyimprovedbyplacingthepotonapot“stand”—threeorfourstones,acoupleoftwigs,asmallwirerack,etc.—locatedinsidethebag.Thishelpscreateathinlayerofairunderthepot,reducingheatlosstothecookeritself.Foroptimalperformance,Dr.StevenJonesof

BrighamYoungUniversityrecommendsraisingthepot6centimeterswithanopen-meshwirestandlocatedinsidethebag(seeimagebelow).Thisallowssunlighttobereflectedunderneaththepotaswellasonthesidesandtop.Forbestpotstabilitymakethewirestandslightlywiderthanthepot,andslightlytallerthan6centimeters,sothatthepotcanrestinsidethestandontwocrossedwiresatthe6centimetersheight.Again,thesestepsareoptional.

3.AssembletheCooKit.

Inashadedarea,laytheCooKitshinysideupsothatthewide(back)panelisawayfromyou.Tiltthebackpaneltowardsyouandcarefullyslidetheendsofitsflapsintotheslotsontheshorterfrontpanelthatisnearesttoyou.(Asyoudothisyouwillneedtoalsotiltthefrontpanelup.)Clamptheinsertedflaps,ontheundersideofthefrontpanel,usingclothespinsorsimilardevice.


15

4.Chooseacookinglocation.

Setthecookeronadry,levelsurfaceindirectsunshineawayfrompotentialshadows.Forbestresults,solarcookingrequirescontinuous,directsunshinethroughoutthecookingperiod.

5.OrienttheCooKit.

OrienttheCooKitaccordingtothedetailsbelow.Onceoriented,theCooKitdoesn’tneedtobemovedagainduringthreetofourhoursofcooking.Forlongercooking,orforlargequantitiesoffood,reorientingthecookereverycoupleofhoursspeedscookingalittle.Foodcooksfastestwhentheshadowcreatedbythecookerisdirectlybehindit.

•TOCOOKANOONTIMEMEALorientthecookersothattheshorter,frontpanelfaceseasterly,orapproximatelywherethesunwillbemid-morning.Ingeneral,itisgoodtogetthefoodoutearlyandnottoworryaboutituntilmealtime.Formostdishesyoushouldstartcookingby9:00or10:00a.m.

•TOCOOKANEVENINGMEALorientthecookersothattheshorter,frontpanelfaceswesterly,orapproximatelywherethesunwillbemid-afternoon.Formostdishes,itisbesttostartcookingby1:00or2:00p.m.

•FORALL-DAYCOOKINGorientcookerwheresunwillbeatnoonorearlyafternoonandfoodwillbereadyandwaitingfortheeveningmeal.

6.Adjustfrontflap.

Raiseorlowerthefrontflapsothereisasmallshadow,nomorethanhalfitswidth,underit.Theflapshouldbeangledhigherwhenthesunishighandlowerwhenthesunislow.Youwantthefrontflaptoreflectthesun,notblockit.

Shadow Shadow

16


7.Setthebag-enclosedpotontheflatpartoftheCooKit.

Optional:onwindydays,largestonesorbrickscanbeplacedoneachsideoftheflatpartoftheCooKitthatextendsbeyondthesidereflectivepanels,aswellasunderthefrontpanel.

8.Leavefoodtocookforseveralhoursoruntildone.

Thereisnoneedtostirfoodwhileitiscooking.

9.Removethepot.

Usingpotholders,removethepotfromtheCooKit.(PotsgetVERYhot.)Topreventsteamburns,openthebagawayfromyouwhenremovingthepot,andslidepotlidtowardyouwhenopeningpot.

Enjoyadeliciousmeal!Forlessglarefromthereflectorwhenputtinginortakingoutfood,standorsquatinfrontoftheCooKitwithyourbacktothesuntomakeashadow.Manysolarcooksalsowearsunglasses.


17

Careandstorage

StoretheCooKitinasafeplaceawayfrommoistureandanimals,preferablyindoors.Periodicallywipereflectivesurfacesgentlywithadrycloth.Ifthecardboard(cartonboard)accidentallygetswet,layitflat—shinysidedown—untildry.

Allowplasticbagstoair-dryorgentlywipedrywithatowel.Heat-resistantbags,handledproperly,shouldlast10ormoreuses.Bagsgraduallybecomebrittlefromexposuretosunlightandheat,andwilleventuallydevelopsmalltears.Tapecanbeappliedtotheoutsideofsmalltearstotemporarilyextendbagusefulness.

TheCooKitisdesignedtobecompactandportable.Whennotinuseitcanbesimplyfoldedlengthwiseintothirdsor,ifneeded,foldedflattoabout33centimeters(13inches)square.

FoldtobackFoldtofront

18


MOD

EL2:

BOX

COO

KER Thisboxcookertakesonetotwodaystomake,plusovernightdrying.Itcookstwoto

threepotsoffood.Ifrocksorbricksareheatedalongsidethepots,theboxcookerwillmaintainheatforacoupleofhoursaftersunsetwiththelidclosed.


•Twolarge,shallowcorrugatedcardboard(cartonboard)boxes,nestableasfollows:

AnINNERBOXatleast45x55centimeters(18x22inches),preferablyjustalittlebittallerthanyourpots.

AnOUTERBOXalittlelargerinalldimensionssothereisatleast3-5centimeters(1-2inches)spacebetweenthetwoboxesonallsideswhennested.Idealproportions:oneunittallbytwounitslong(fronttoback)bythreeunitswide(sidetoside).Cookersthataretootallcreateshadowsacrossthepotandincreaseheatlossthroughwalls.

•Corrugatedcardboard(cartonboard)atleast15centimeters(6inches)longerandwiderthantheouterboxtomakethelid

•Windowglassatleast50x60centimeters(20x24inches)andlongerandwiderthantheinnerbox

•Thin,blackmetalsheet,sizedequaltoorslightlysmallerthantheinnerbox

•Aluminumfoil—0.3x20meters(1x60feet),cutintostripsasneeded

•Dryplantfibersorabout50sheetsofnewspaper,quarteredandlooselycrumpled

•Glue(nontoxic,water-based)

•Siliconecaulk

•Rigidwire(hangerwire,etc.),orastickandstring—0.7meters(2feet)each

•Paintbrush(thefoamtypeworkwell)


•Pencil,penorothermarkingdevice

•Largerulerorotherstraightedge


Glass

Lidpiece

Metalsheet

Innerbox

Outerbox


19

Constructionsteps

1.Cutwindowopeninginouterbox.

Turnouterboxupside-down.Onitsbottom,centertheinnerboxanddrawalinearoundit.

Cutoutthispiecetomakeawindowopeningthesamesizeastheinnerbox.Thereshouldbeasmallrimonallfoursides5-7centimeters(2-3inches)wide.

2.Onlidpiece,makefoldlinesandcutwindowopening/reflectorflap.

Centertheouterboxonthelidpieceandtracearoundit(thesearefoldlines).Extendtheselinesouttotheedgesofthelidpiece.

Centertheinnerboxbetweenthefoldlinesonthelid(thatyoujustdrew)andtracearoundthisboxaswell.

Cutonlythreesidesoftheinnerline—twoshortsidesandonelongone.Folduptheresultingflapforthereflector,creatingawindowframeopeningthesamesizeastheinnerbox.

20


3.Adjustheightofboxes,ifneeded.

Setacookingpotnexttobothboxes.Theinnerboxneedstobejustalittletallerthanyourpots.Theouterboxneedstobejustalittletallerthantheinnerbox.

Iftheboxesaretootall:

ONTHEINNERBOXmakeamarkabout3centimeters(1inch)abovethetopofthepotanddrawafoldlinestraightaroundthefourboxwalls.Scorethefoldlineswithabluntedgesuchasaspoonhandle.

ONTHEOUTERBOXmakeamarkabout5centimeters(2inches)abovethetopofthepotanddrawafoldlinestraightaroundthefourboxwalls.Scorethefoldlineswithabluntedgesuchasaspoonhandle.

Cutthecornersofbothboxesdowntothefoldlines.

Foldsidesoutwardsalongthecreases.

4.Triminnerboxflaps.

Whenthewallsoftheinnerboxarefoldeddowntotherightheight—orifyoudidn’thavetoadjustyourboxheight—trimoffatabout5-7centimeters(2-3inches)abovethefoldedcreasetomakeflapsasnarrowasthesmallrimaroundthewindowopeningontheouterbox.(Refertostep1,page19.)


21

5.Joinboxes.

Turntheouterboxright-sideup,sothewindowopeningandrimaredown.Spreadglueontheinsideoftherim.

Turntheinnerboxupsidedownandloweritintotheouterbox,ontotheglue.Pressthesmallflapsagainsttheinsideoftherimaroundthewindowopeningtojointhetwoboxesintoonedouble-walledbox,nowopenatthebottom(whichshouldbefacingupatthispoint).

6.Insulateandseal.

Withoutdisturbingthedryingglue,carefullyspot-gluealuminumfoilonbothwallsandtheundersideoftheinnerbox,coveringallsurfacesbetweenthetwoboxes.Thislayeroffoilhelpstoinsulatethecooker.

Lightlyfillthegapsbetweenthetwoboxeswithcrumplednewspaper,plantfiberorotherinsulation.

Addafewstripsofcardboardandmorecrumplednewspaperorotherinsulationontheundersideoftheinnerbox(whichshouldbefacingupatthispoint).

Closeandgluetheflapsoftheouterboxtosealthebottomofthecooker.

22


7.Gluefoilinsidetheboxandlid.

Turnboxright-sideup.

Diluteglue1:1withwaterand,usingapaintbrush,spreaditthinlyonthedullsideofsheetsofaluminumfoil.

Pressthegluedsheetsofaluminumfoiltightlyandsmoothlylikewallpapertotheinsideandrimofthebox.Afewwrinkleswon’thurt.Setasidetodry.

Repeatingtheprocedure,gluefoiltotheundersideofthelidflap(thefoldedupcenterpartonly).

8.Cut,foldandgluethecornersofthenewlid.

Withthelidupsidedown(foilfacingup),makeonecutateachofthefourlidcorners,justtothefirstfoldlines.(Cutsshouldbeparalleltothelongsideofthelid.)Scoreallfoldlineswithabluntedgesuchasaspoonhandleandfoldalongcreaseswithastraightedge.

Overlapandgluethecorners,andholdwithclothespinsorclampsuntiltheglueisdry.Tomakequickclamps,cutcardboard-widthslitsinasmallstackofcardboardpieces.

9.Insertthewindow.

Spreadsiliconecaulkalongtheundersideedgeofthewindowopeningrim(outsidethecutedgeofthefoiledreflectorpiece),thenpresstheglassinfirmlybutcarefullytomakeagoodsealwiththecaulk.

Letboxandliddryovernight.


23

10.Makeanadjustableprop.

Makesmallholesinacornerofthelidreflectorandsideoflidasshown.Loopstringthroughtheholes.

Makeseveralnotchesinastick,andtiethestickatbothendstoholdupthereflectorandallowangleadjustments.

~or~

Bendasturdywireatbothendsandgluecorrugatedcardboard(cartonboard)stripstothelidandreflectorasshown.Thewirecanbeinsertedintoanyofthecorrugationsforangleadjustments.

11.Addtheblacktrayand“cook”thecooker.

Puttheblackmetalsheetinsidethebox.(Thepotswillsitonthislight-absorbingsheet.)Putonthelid,withthelidreflectorproppedopen,andaimtowardthesunforseveralhourstodriveoutthelastbitofmoistureandanypaintorgluefumes.

24


Cookingdirections

1.Putfoodindarkpot(s)withdark,tight-fittinglid(s).

2.Chooseacookinglocation.

Setthecookeronadry,levelsurfaceindirectsunshineawayfrompotentialshadows.Forbestresults,solarcookingrequirescontinuous,directsunshinethroughoutthecookingperiod.

3.Putpot(s)incookerandreplacelid.

Putpot(s)incooker.Ifcookingmultipledishes,quickercookingitemsshouldbeplacedtowardsthefrontofthecooker(oppositethereflector)andslowercookingitemstowardstheback,whereaccesstosunlightisbest.Placelidoncooker.

4.Orientthecooker.

Orientthecookeraccordingtothedetailsbelow.Onceoriented,thecookerdoesn’tneedtobemovedagainduringthreetofourhoursofcooking.Forlongercooking,orforlargequantitiesoffood,reorientingthecookereverycoupleofhoursspeedscookingalittle.Foodcooksfastestwhentheshadowcreatedbythecookerisdirectlybehindit.


25

•TOCOOKANOONTIMEMEALorientthecookersothatthefrontside(oppositethereflector)faceseasterly,orapproximatelywherethesunwillbemid-morning.Ingeneral,itisgoodtogetthefoodoutearlyandnottoworryaboutituntilmealtime.Formostdishesyoushouldstartcookingby9:00or10:00a.m.

•TOCOOKANEVENINGMEALorientthecookersothatthefrontside(oppositethereflector)faceswesterly,orapproximatelywherethesunwillbemid-afternoon.Formostdishes,itisbesttostartcookingby1:00or2:00p.m.

•FORALL-DAYCOOKINGorientcookerwheresunwillbeatnoonorearlyafternoonandfoodwillbereadyandwaitingfortheeveningmeal.

5.Adjustreflector.

Withtheadjustableprop,anglethereflectorsothatmaximumsunlightshinesonthepots.

6.Leavefoodtocookforseveralhoursoruntildone.

Thereisnoneedtostirfoodwhileitiscooking.

7.Removethepot(s).

Usingpotholders,removethepot(s)fromthecooker.(PotsgetVERYhot.)Ifyouwon’tbeeatingforacoupleofhours,youmaywanttoleavethepotsinthecookerandclosethelid.Theinsulativepropertiesofthecookerwillkeepthefoodwarmforawhile.

Enjoyadeliciousmeal!

Careandstorage

Storethecookerinasafeplaceawayfrommoistureandanimals,preferablyindoors.Periodicallywipereflectivesurfacesgentlywithadrycloth.

Correctangle IncorrectangleIncorrectangle

26


SUBS

TITU

TEM

ATER

IALS Cookerforms(bodies)

Panelandboxcookersareeasilyandinexpensivelybuiltusingcorrugatedcardboard(cartonboard)astheform.Toincreasedurability,outer,non-reflectivesurfacescanbepainted,oiledorwaxedtohelpprotectfrommoisture.

FORMSFORPANELCOOKERSshouldberigidanddurable.Anumberofmaterialswillwork,including:

•Plainorcorrugatedplastics

•Wood

•Wovenmats

FORMSFORBOXCOOKERS(OUTERBOX)shouldbemadeofmaterialsthatholdinsulationandsealwellwiththelid.Anumberofmaterialswillwork,including:

•Plainorcorrugatedplastics

•Wood

•Metal

•Masonite

•Bricksoradobe

•Papier-mâché

FORMSFORBOXCOOKERS(INNERBOX)mustwithstandhightemperatureswithoutreleasingfumes.Thesurfacethatfacesthecookingpotshouldbereflective,linedwithreflectivematerial,orblack.Anumberofmaterialswillwork,including:

•Wood

•Sheetmetal

•Masonite

•Wovenbasketsormats

•DON’TUSEStyrofoam,vinylplastics,bricksoradobe

Glues

Water-basedpolyvinylacetateglues—suchasElmer’sGlue-All®—canbediluted1:1withwater.Wheatorriceflowerpaste,acaciagum,andcaseinglueareotheroptions.Avoidpetroleum-andrubber-basedglues.Somecookermaterialscanbesewnorstapled.Don’tusetapeforinnercookersurfaces.

Darkcookingpots

Foodissolarcookedinlidded,dark-coloredpotsorsimilarvessels.Thinmetalpotsworkbest.Tintedglassbakingdishesalsowork,asdoheavymetal,ceramicorclaypots,butthemassofthesematerialsabsorbsheatresultinginaslowercookingprocess.


27

Ifyoudon’thavedark-coloredpotsandlids,youcanpaintthemblack(outersurfacesonly).Dull,nontoxiclatexorblackboardpaintsarepreferred.Ifoil-basedpaintisused,“bake”thepotinthesunforseveraldaystogetridofanyodor.Water-basedgluemixedwithsootorposterpaintworksalso,butislessdurable.

Glassjarswithlidscanbeusedifpaintedblack.Youcanplaceaverticalstripoftapeonthejarbeforepaintingandthenremovethetape,leavingaspacetoviewfoodwhilecooking.Canningjarsandlidsarerecommendedbecausetheyaredesignedtoreleaseexcessivesteampressureifneeded.

Transparentheattraps

Transparentheattrapsletinsunlightandholdinheat.Inpanelcookersthisistypicallyaheat-resistantplasticbag—abletowithstandingtemperaturesupto150ºC(300ºF)—surroundingthecookingpot.Inboxcookersthisisaglassorplasticwindow.

TRANSPARENTHEATTRAPSFORPANELCOOKERS:

•Polypropylenebags

•Nylon(polyamide)bags,acommontypeof“ovenbag”

•Polyesterbags,acommontypeof“ovenbag”

•High-densitypolyethylene(HDPE)bags—thecrinkly-soundingbagswithhandlesusedtocarrygoodsfromstoresinmanycountries,oftenbearingthe#2recyclesymbol—areacceptableifmostlyclear

•InvertedglassorPyrex®bowlsoverthecookingpot,ifbigenoughtorestdirectlyonthecookertosealtheairspacearoundthepot.(Note:overtime,moisturereleasedduringcookingcandamagecardboardsolarcookers.Ifyouuseaninvertedbowl,considerplacingthepotandthebowlonaclearglasstrayordishwithaslightlyraisededgetopreventaccumulatedmoisturefromrunningontoanddamagingthecooker.)

TRANSPARENTHEATTRAPSFORBOXCOOKERS:

•Ordinarywindowglassoroldcarwindowsifun-tinted

•Adoublelayerofheat-resistantplastics,eitherpolypropylene,polyesterorpolycarbonate,4-milthickwith1centimeter(1/4inch)airspacebetween.Somethickerplasticsworkfinewithonelayer.Don’tusemostplasticsorfiberglass,whichmaygiveofffumeswhenheated.

•Large“ovenbags”maybegluedtothewindowframewithalittleairspacebetweentwolayers

28


Reflectivesurfaces

Mostsolarcookersuseoneormorereflectivesurfacestodeliverextrasunlighttothecookingpot.Reflectorsshouldbeshiny,fairlyrigid,andnoteasilydamaged.Werecommendaluminumfoilmountedoncardboard,whichmakesforasimple,effectivereflector.

Otherreflectivesurfaces:

•Aluminizedpolyesterfilm(Mylar®),ifreflective,canbeusedforpanelcookersandthereflector(s)ontopofaboxcooker.Don’tuseinsideaboxcooker,however,becauseitmightmeltorgiveofffumes.(Thismaterialcanbetrickytoadheretorigidbacking.Itcanbesewnonifnecessary.)

•Mirrors,thoughtheyareheavyandfragile

NOTrecommended:

•Sheetmetals,includingaluminumandsteel,aren’textremelyreflectiveandtendtoabsorbsomeradiation,makingthemlesseffective.(Theexceptioniscertainanodizedaluminums.)

•Metallicpaintsarenotreflectiveenough

Insulation(boxcookeronly)

Insulationmaterialsmustbepoorconductorsofheatandtoleratehightemperatureswithoutmeltingorgivingofffumes.Newspapers—quarteredandlooselycrumpled—arecheap,readilyavailableandeasytoworkwith.

Otherinsulationmaterials:

•Anextralayeroffoil-coveredcardboard(cartonboard)andemptyairspacesineachwall

•Dryplantfibers—ricehulls,straw,walnutorpeanut(groundnut)shells,coconutfibers,driedbananaleaves

•Feathers

•Wool

•DON’TUSEStyrofoam,polyvinylorotherplasticsthatmeltorgiveofffumesatcookingtemperatures

SECTION4SOLARRECIPESANDTIPS

30


Youcancookalmostanythinginyoursolarcooker,includingvegetables,meats,grainsandlegumes.Youcanevenbakebreadsanddesserts!However,simplesolarcookerscannotstir-fryorcookflatbreadsthatrequirehightemperatures.

Tips:

•Solarcookingisnotanexactscience.Manyfactorsinfluencecookingtemperaturesandtimes,includingtimeofyear,timeofdayandintensityofsun.Expectcookingtimesatleastdoublewhatyouareusedto.Ingeneral,putthefoodoutearlyanddon’tworryaboutit.Solarcookingiseasy!

•Foodscookfastestbetween10a.m.and2p.m.,whenthesun’senergyismostintense.

•Thin,black,metalpotswithlidsworkbest.Shallow,widepotsarebetterthantall,narrowones.Seepage26forpotoptions.

•Theamount,volumeandheightoffoodinthepotinfluencecookingspeed.Smallquantitiesoffood,andfoodcutintosmallpieces,cookfastest.Foodshouldbenodeeperthanahandwidth.

•Whenrecipesinstructto“addthis,cook10minutes,thenaddthat,”youcanusuallyjustputalltheingredientsinatonce.

•Many,ifnotmost,ofyourfavoriterecipeswillworkinasolarcooker—oftenwithoutanyadjustments.Slow-cookerrecipesworkparticularlywell.Beadventurous!


31

Barley,corn(maize),millet,oats,quinoa,rice,wheat,sorghum:mixwiththeusualamountofwaterandcookinadark,coveredpot.Noneedtostirwhilecooking.Ifthetextureistoowetordry,adjusttheamountofwaternexttime.Somepeopleheatwateranddrygrainintwoseparatepotsbeforecombiningtogetthepreferredtexture,butthisextrastepisusuallynotnecessary.

Rice

Combine1partriceto11⁄2-2partswater.Cook1-2hoursinadark,coveredpot.Subsequently,adjustwatercontentasnecessary.

Variations:

•Priortocooking,mixinfinely-choppedvegetables,suchasonions,celeryand/orcarrots.Reduceamountofwaterslightly.Cook2-3hours.

•Priortocooking,placeraw,choppedchickenpiecesontopoftherice/watermixture.Reduceamountofwaterslightly.Cook2-3hours.

Maizemeal(ugali,sadza)

Combine1partmaizemealto1-11⁄2partscoldwater.Stirwelltoavoidlumps.Cook2-3hoursinadark,coveredpot.(Traditionally,maizemealrequiresconstantstirringasthemealisaddedtoboilingwater.Withthissolarcookingmethoditdoesnot.)

Cookedcereals

Youcan’tsolarcookearlyinthemorning,butyoucansolarcookyourfavoritecerealthedaybeforeandeatitcoldorquicklyreheatitoverafireoronastove.

Pasta

Heatwaterinadark,coveredpot.(Uselesswaterthanyounormallywould.)Putdrypasta,withabitofcookingoil,inaseconddark,coveredpotandsetitinthesuntowarm.ThissecondpotdoesNOTneedtobeinthesolarcooker,however.Whenthewaterisnearboilingaddthewarmpasta,stir,thencoverandsolarcookfor10-15additionalminutes.

GRAINS,PASTA

32


Lasagna

•1liter(1quart)pastasauce

•1/4kilogram(1/2pound)uncookedlasagnanoodles

•1/2kilogram(1pound)ricottacheese

•1/2kilogram(1pound)shreddedmozzarellacheese

•Parmesancheesetotaste

•1/2kilogram(1pound)groundbeef—optional

Pour1/3ofthepastasauceintoadarkroasterpan.Coathalfoftheuncookednoodleswithricottacheesetomakeabottomlayerinthepan,andtopwithhalfoftheshreddedmozzarella.Repeattomakeasecondlayer.TopwithremainingpastasauceandtheParmesancheese.Coverandbakefor3hours.

Formeatlasagna,firstbrowngroundbeef—inadark,coveredpot—for11⁄2hoursinasolarcooker.Drain.Addmeattopastasauceandprepareasabove.

Forfastercooking,soakmostbeansinwaterovernight.(Pintobeans,lentilsandsplitpeasdon’tneedtopre-soak).Putbeansandusualamountofwaterinadark,coveredpotandcookfor3-5hoursormoredependingonbeantype.Optionalingredients—includingsalt,tomatoesandonions—shouldbeaddedafteratleast2hoursofcooking.Ifdesired,ricecanbeaddedtocookwithbeansforthelast1-2hours.

“Refried”beans

•1cupdriedpintobeans

•3cupswater

•1/2cuponions,chopped

•1/2teaspooncumin

•1/2teaspoonsalt

•garlicpowdertotaste

•peppertotaste

Combinebeans,waterandonionsinadark,coveredpotandcookfor4-6hoursoruntilbeansaresoft.Drain(butsave)theliquid.Mashthebeans,addingreservedliquidtogettheconsistencyyouprefer.Addspicesandmixwell.

LEGU

MES


33

Addlittleornowater;meatscookintheirownjuices.Thelongermeatscook,themoretendertheybecome.Smallerpiecescookfaster.

Potroast

Chopandcombinepotatoes,carrots,onionsandothervegetablesinadarkpot.Placeroastontopandseasonasdesired.Coverandcookfor4+hours.Remember,thisrequiresnoaddedwater;naturaljuicescomingfromthemeatandvegetableswillblendtheflavorsnicely.

Chili

•1/2kilogram(1pound)groundbeef

•1onion,chopped

•1greenpepper,chopped

•2garliccloves,minced

•2cupsfreshtomatoes,chopped;or1cuptomatosauce

•2cupscookedkidneyorpintobeans

•1tablespoonchilipowder

•1/2teaspoondriedbasil,crushed

•Saltandpeppertotaste

Browngroundbeef—inadark,coveredpot—for11⁄2hoursinasolarcooker.Drain.Addremainingingredients,coverandcookfor2+hours.

Fish

Washfishsteaksorfilletsanddrainwell.Cookinadark,coveredpotfor1-2hoursormore.(Fishmaybedonesooner,butwon’tovercook.)Butter,lemon,etc.maybeaddedatthebeginning.

MEATS

34


Addnowater.Rootvegetablescookbeautifullyinasolarcooker,usuallyin3-4hoursinadark,coveredpot.Smallerpiecescookfaster.Above-groundvegetablesusuallycookin1-11⁄2hours.Ifcookedlongertheylosetheirnicecolor,buttheflavorshouldbefine.Greenscookquicklyandcanovercook,sokeepaneyeonthem.Theysteamnicelyatopgrainsormeatsduringthelastfewminutesofcooking.

Cornonthecob

Corncookswellwithoutwaterinadark,coveredpotorjar.Alternatively,leavecorninhusksandcookinablacksock.Cook1/2-1hour.

Stewedtomatoes

•Wholetomatoes

•Bread,cutintosmallpieces

•Cheese

•Basilorotherherbs

•Saltandpeppertotaste

Slicetomatoespartwaydownintoquartersandplaceinadarkmuffintinorcakepan.Toptomatoeswithbread,herbs,spicesandcheese.Coverandcook2hours.(Aseconddarkmuffintinorcakepancanbeinvertedandusedforthelid.)

Bakedpotatoes

Washpotatoes.Oiltheskinsifyoulikethemsoft.Cook4+hoursinadark,coveredpot.

Wintersquash

Wintersquash(butternut,acorn,spaghetti,etc.)cookwellinasolarcooker.Wash,peelandcoarselychopsquash.Mixinalittlebutterandbrownsugarifdesired.Cook1-2hoursinadark,coveredpot.

Pineappleyams

Peelanddiceyams.Mixinpineapplechunksandabitofjuice.Cook2-3hoursinadark,coveredpot.

VEGE

TABL

ES


35

Applesauce

•2kilograms(4pounds)apples,peeledandsliced

•1cupwaterorcider

•Sugarorhoneytotaste

Combineapplesandwaterorciderinadarkpanandcook,covered,for2+hoursuntilverysoft.Processthroughafoodmillorsimilardevice,addingsugarorhoneyasdesired.

Peachmeringue

•5peaches,halved

•5teaspoonsbrownsugar

•Cinnamontotaste

•3eggwhites

•1teaspoonvanilla

•3/4cupgranulatedsugar

Placepeachescutsideupinadarkpiepanorcasseroledish.Place1/2teaspoonbrownsugarincavityofeachpeachhalfandsprinklewithcinnamon.Coverandbake11⁄2hours.

Beateggwhitesatmediumspeeduntilsoftpeaksform.Addvanillaandgraduallyaddgranulatedsugarwhilebeatingathighspeed.

Removepeachesfromcookerandtopeachpeachhalfwithmeringue,coveringcompletely.Returntosolarcookerandbakeuncoveredfor1hour.

FRUIT

36


Bakingisbestdoneinthemiddleoftheday—between10a.m.and2p.m.—indark,coveredpans.Ifyourbakingpansdon’thavelidsyoucaninvertaseconddarkpanasalid.Bakecrustsseparatefromfillings.

Wholewheatbread

•1tablespoondryyeast

•21⁄2cupshottapwater

•1/2tablespoonsugar

•6cupswholewheatflour(or31⁄2cupswholewheatflourand21⁄2cupswhiteflour)

•1tablespoonsalt

•1/3cupoil

•1/3cuphoneyorsugar

Sprinkleyeastinto1/4cuphottapwater.Letstand15minutes.Add1/2tablespoonsugar.Combinetheremaining21⁄4cupshottapwaterwith31⁄2cupswholewheatflourinalargebowl.Addsalt,oilandhoneyorsugar.Continuemixinguntilwellblended.Add1/2cupflourtomixture.Addpreparedyeasttomixtureandblendthoroughly.Add11⁄2-2cupsmoreflour.Kneadfor10minutesoruntilthereisaconsistencylikecookiedough.Dividedoughintotwoparts.Moldintoloavesonoiledcounter.Placeindark,oiledpans.Ifdesired,oiltopofloavesforsoftercrust.Coverloaveswithdampclothandletrise1/3inbulk.Coverandcookfor21⁄2hours,ideallybetween10a.m.and2p.m.

Lightbreadpanswithoutcoversmaybeusediftheyareplacedinsideofdark,coveredpotslargeenoughtoholdthem.

(AdaptedfromarecipesubmittedbyJacquelineParrish.)

AmericanIndianfancycornbread

•1/4cupbutter

•1/3cuphoney

•2eggs

•1cupcannedpumpkin

•1/4cupmilk

•11⁄2cupsbluecornmeal

•3/4cupwholewheatflour

•3teaspoonsbakingpowder

•1teaspoonsalt

BREA

DS,B

AKED

GOO

DS


37

•1cupblueberries

•1/2cupnuts,chopped

Inadarkpot,beatbutter,honeyandeggstogetheruntilsmooth.Stirinpumpkin,milkandcornmealandbeatuntilsmooth.Siftinflour,bakingpowderandsaltuntilcombined.Foldinblueberriesandnuts.

Coverandbake2-3hours.

(FromSolarCookingNaturallybythelateVirginiaHeatherGurley.)SolarCookingNaturallybythelateVirginiaHeatherGurley.)SolarCookingNaturally

Eggs

Leaveeggsinshellsandcookfor1-2hoursinadark,coveredpot.(Waterdoesnotneedtobeadded.)Withlongercookingwhitestendto“tan”butflavorisfine.

Custard

•1egg

•1cupofmilk

•2-3tablespoonsofsugar

•1/4teaspoonsalt

•1/2teaspoonvanilla

•Nutmegtotaste

Mixtogetherallingredientsandsprinklewithnutmeg.Bakefor11⁄2hoursinadark,coveredpot.Letcoolbeforeserving.

Saucesandgravies(withflourorstarch)

Heatjuicesandflourseparately,withabitofcookingoilintheflour.Thencombineandstir.Itwillbereadyquickly.

Roastingnuts

Roastindark,uncoveredpanortray.Almondstakeabout1hour,peanuts(groundnuts)about2hours.

Beverages

Solarcookerseasilyheatwaterforwarmbeveragesliketeaandcocoa.

OTHERFOODS

38


Nachos

Spreadcornchipsonadarkmetaltrayandsprinklewithshreddedcheese.Whencheeseismelted,nachosareready.

“Solarcued”hotdogs

Placeasinglelayerofhotdogsinadarkpotandheat,covered,untilwarm.Hotdogscanalsobeslicedandmixedwithbarbecuesaucepriortoheating.

Solars’mores

Placemarshmallowsandpiecesofchocolateand/orpeanutbutterbetweengrahamcrackers.Heatinadark,coveredpotuntilmarshmallowsmelt.

Fruitcut-ups

Sprinkleslicedappleswithcinnamonandsugar,andcookinadark,coveredpotuntildone(anywherefromslightlytendertoverysoft).

QUIC

KTR

EATS

SECTION5ALTERNATIVESOLARCOOKERUSES

40


SOLA

RPA

STEU

RIZA

TION

Disease-causingorganismsinwaterarekilledbyexposuretoheatinaprocesscalledpasteurization.Waterthathasbeenheatedto65ºC(149ºF)forashortperiodoftimeisfreefrommicrobesincludingEscherichiacoli,Rotaviruses,GiardiaandtheHepatitisAvirus.Ataround71ºC(160ºF),milkandfoodarepasteurized.Boilingisnotrequired.

Microbe Killedrapidlyat

Worms,Protozoacysts(Giardia,Cryptosporidium,Entamoeba)

55°C(131°F)

Bacteria(V.cholerae,E.coli,Shigella,Salmonellatyphi),Rotavirus

60°C(140°F)

HepatitisAvirus 65°C(149°F)

Whypasteurize?

Worldwide,unsafewaterisamajorhealthproblem.Overonebillionpeopledonothaveaccesstosafewater.Preventablewaterbornediseasesareresponsibleforapproximately80%ofallillnessesanddeathsinthedevelopingworld.Childrenareespeciallysusceptible,withnearlytwomilliondeathseachyear.DiseasesspreadthroughcontaminatedwaterincludeAmoebiasis(AmoebicDysentery),Campylobacteriosis,Cholera,Cryptosporidiosis,Dracunculiasis(GuineaWormdisease),Giardiasis,HepatitisA,Shigellosis(BacillaryDysentery)andTyphoidFever.

Howispasteurizationaccomplished?

Traditionalfuelscanbeusedtopasteurizewater,butonsunnydayssolarenergycanbeusedaswell.Simplesolarcookerscanpasteurizewaterforafamilyatarateofabout1liter(1quart)perhour.SolarCookersInternational’sreusableWaterPasteurizationIndicator(WAPI)canbeusedtodeterminewhenwaterheatedbyPasteurizationIndicator(WAPI)canbeusedtodeterminewhenwaterheatedbyPasteurizationIndicator

solarorconventionalmeanshasreachedappropriatetemperaturestomakeitsafe.

Solarpasteurizationdirections

1.Pourwaterintoablackpotorjarofthetypeusedforcooking.

2.InsertWAPIintowater.

InsertaWAPI,washerdownandwaxup,intothewaterwiththeendofthe


41

stringoutsidethepotorjar.ThewasherendoftheWAPIshouldtouchthebottomofthepotorjar,andthewaxendshouldbehigher.Carefullyreplacethelid.

3.Orientthecookeraccordingly(seecookingdirectionsforyourcookertype).

4.Placethepotorjarinthecooker.

5.Allowwatertoheat.

Leavewatertoheatinasunnyplaceforanumberofhours.Allowatleast1hourperliter(quart)ofwater.

6.Determineifpasteurizationhasoccurred.

WhentheWAPIwaxmeltsandfallstothebottomoftheWAPI,thewaterhasbeenpasteurized.IfyoudonothaveaWAPI,youwillneedtoeithermeasurethewatertemperatureusinganalternatedeviceorobservethewaterboiling.

7.Repeatsteps5and6untilpasteurizationhasoccurred.

8.Allowthewatertocoolbeforedrinking.

Keeppasteurizedwatercovereduntilusetopreventrecontamination.Don’tletfingersoruncleanobjectstouchcleanwater.Ifyouaren’tsure,re-pasteurizewater.

SafetyNotice:Pasteurizationdoesnotremovedangerouschemicals,likearsenic.Pasteurizationisnotthesameassterilization,aprocesswherebyeverything,includingheat-resistantspores,iskilled.Theheat-resistantsporesthatsurvivepasteurizationareharmlesstodrink.Wheresterilizedliquidsareneeded—inhospitalsandincertainfoodcanningprocesses,forexample—hightemperaturesareachievedusingspecialpressurecookers.

BEFOREpasteurization

AFTERpasteurization

42


OTHE

RUS

ES Disinfectdrymedicalsupplies

Disease-causingorganismsindrymedicalsuppliesarekilledbyexposuretoheat.Whenthesemedicalsupplies—suchasinstruments,bandagesandotherclothmaterials—areheatedto149ºC(300ºF)forashortperiodoftimetheyarefreefromnearlyallorganisms.Largersolarcookersreachthistemperatureand,indifficultfieldconditions,canhelpsavelives.Disinfectionofliquidsrequiresspecialequipmentandcannotbeaccomplishedwithordinarysolarcookers.

Preserve(“can”)foods

Acidicfoods—tomatoesandmanyfruits—canbepreservedor“canned”inairtightcontainersbecausetheiracidpreventsfood-spoilingorganismsfromgrowing.(Vegetablescannotbecannedinasolarcooker.)Canninginasolarcookerissimilarto“open-kettle”canningonastove,exceptthejarsdon’tneedtostandinwater.Followregularcanninginstructions:

filljarsalmosttothetopwithfruitandjuiceandputlidsonloosely.Heattwotofourjarsatatimeuntiljuicesstarttobubbleover.(Inapanelcooker,thejarscanallgoinonebag.)Tightenlids,thencool.Checkthelidstoconfirmagoodseal,indicatedbyaconcavedipinthemiddleofthelid.Reheatifnecessary.

Heatwaterformultiplepurposes

Dryfoods(smallquantitiesonly)

Solarcookersaredesignedtoholdinmoisturewhereasfooddryersneedairflowtocarryawaymoisture.However,apanelcookerorboxcookerlidcandrysmallquantitiesoffood:putfood(uncoveredandopentotheair)inthemiddleofthereflectororontopoftheboxwindow.Thereflectedsunlighthastensdryingandkeepsinsectsaway.

Killpantrypests

Tokillinsectlarvaeorbeetlesindryfoodstaples,spreadfoodthinlyonacoveredtrayinthecookerandheat20minutes,stirringonceafter10minutes.

Commercialuseswe’veheardof:•Boilricestrawtomakepaper(Philippines)

•Extractwaxfromhoney(Uganda,USA)

•Dyefabrics

•Heathotdogsforbeachvendors(USA)

•Restaurantandbakeryfoodpreparation(Chile,Kenya,Egypt,USA,Canada)

•Sanitizedishesandutensils

•Pasteurizepottingsoil(USA)

SECTION6IDEASFORTEACHERS

44


QUIC

KIEDE

MO

COOK

IT Youcanmakethis“quickie”versionoftheCooKiton-the-spotforteachingpurposes.Itonlycookssmallquantitiesoffood,butitcanbeusedtodemonstratesolarcookingconceptsbywarmingfoods,meltingcheeseandchocolate,heatingwater,etc.Itisnotintendedasasubstituteforastandardsolarcooker.


•Corrugatedcardboard(cartonboard)box—about0.6x0.6x0.3meters(2x2x1feet)

•Aluminumfoil,cutintostripsasneeded


•Tape(orglueandapaintbrush)


Constructionsteps

1.Cutboxinhalfdiagonallysoeachhalfhastwowallsandatriangularbottom.

2.Tapeanextrastripofcardboardtothecutedgeofthebottomasanadjustablefrontpanel.

3.TapefoilondemoCooKit.

Tape(orglue)aluminumfoiltotheinnersideofthedemoCooKit,includingthefrontpanel.Makesuretheshinysidefacesout.

Cookingdirections

FollowthecookingdirectionsforthestandardCooKitbeginningonpage13.(Somestepsarenotapplicable.)Thefrontflapwillneedtobeproppedupwitharockorsimilarobject.


45

SOLARACTIVITIESSolarenergyhasmanyhouseholdusesandwillbecomemoreimportanttofuturegenerationsasfossilfuelsandtreesareusedup.Thefollowinglearn-by-doingactivitiesexploresolarenergy,howsolarcookersworkandhowtoputsolarenergytoworkinotherways.Theycanbeadaptedforallages.

Light

Sunlightaffectsmaterials,andmaterialsaffectsunlightinvariousways.

•Ifthematerialistransparent(likesomeglass,plastics,water,etc.),lightgoesrightthroughitalmostasthoughitisn’tthere

•Ifmaterialisshiny,itreflectsmostlightaway

•Ifmaterialisverydark,lightseemstosoakinanddisappear.Itisabsorbed.

Whatyouneed

•Asunnyday(earlyorlate,whentherearelongershadows)

•Asunnywall

•Oneormoreitemsthatare(1)transparent—clearplasticbag,glass,etc.,(2)metallicshiny—metalpot,mirror,etc.,(3)blackmetal,(4)blackordark-coloredcloth,and(5)whiteorlight-coloredcloth

Activities

1.Havestudentsholdtheitemsnearthesunnywall.

Discusswhichonesletlightthrough(transparentitems)andwhichblockthelightandmakeshadowsonthewall.

46


2.Havestudentsholdtheitemsinthesunlightandmovetheitemstotrytoshineabrightspotsomewhereontheground.

Discusswhichmaterialsreflectlight(shinyandlight-colored)andwhichonesabsorblight(darkmaterials).

Changinglighttoheat

Whenabsorbed(notreflected),lightseemstodisappear.Whathappenstoit?

Whatyouneed

•Asunnyday(earlyorlate,whentherearelongershadows)

•Asunnywall

•Oneormoreitemsthatare(1)transparent—clearplasticbag,glass,etc.,(2)metallicshiny—metalpot,mirror,etc.,(3)blackmetal,(4)blackordark-coloredcloth,and(5)whiteorlight-coloredcloth

Activities

1.Setoutallthematerialsinthesun(tochecklater).

2.Haveastudentstandinthesunwitheyesclosedandbothhandsoutstretched,likeastatue.Putwhiteclothoveronehandandblackclothovertheother.

Haveotherstudentsguesswhichhandwillfeelhotter.Thenask“statue”—withoutopeningeyes—totellwhichhandfeelshotter.(Thehandwiththeblackclothshouldquicklyfeelwarmer.)Leteveryonetrythis.


47

3.Haveeachstudentstandbythesunnywalltomakeashadowonthewall.

Askthemiftheirfrontandbackfeeldifferent.(Ontheirsunnysidetheyareabsorbingsunlightandchangingsometoheat.)

4.Havestudentsfeelalloftheitemswhichhavebeensittinginthesunlightanddecidewhichishottestandwhichiscoolest.Seeiftheyallagree.

Askwhichtypesofmaterialsgethotter—thosethatreflectorthosethatabsorb.(Blackitemsshouldbehottest,shinyandtransparentshouldbecoolest.)

Heat

Heatnaturallyspreadsfromwarmerplacestocoolerplaces.Somematerialsspread(conduct)heatandotherskeepitfromspreading(insulate).

Whatyouneed

•Asunnyday

•Solarcookertoheataliter(quart)ofwater

•Fouridenticaljarsorcontainerswithlids

•Plasticbag

•Crumplednewspaperoralargecloth

•Pieceofheavypaperorahandfan

Activities

1.Earlyintheday,setwaterinthesolarcookertoheat.

2.Whenwaterisquitehot(butnothotenoughtocauseburns)pourequalamountsintoeachofthefourjarsandtightenlids.

•Putjar#1insideaplasticbag

•Wrapjar#2incrumplednewspaperorlargecloth

•Setjar#3intheopenair

•Setjar#4intheopenairawayfromtheothers.Taketurnsfanningit.

3.After10minutescomparehowhotthewaterisineachjar.

4.Discusswhatthingshelpheatescape(openair,breezes)andwhatthingsinsulate(cloth,crumplednewspaper,asmalllayeroftrappedairinabag).

48


Dailyvariationsinsolarenergy

Evenoncloudlessdays,theamountofsolarenergychangeswiththetimeofdayandthetimeofyear.Solarenergyisstrongestwhenthesunishighinthesky(whenshadowsareshortest).

Whatyouneed

•Asunnyday

•Opengroundthatwillbesunnyalldayand2sticksorpencils~or~

•Openpavementthatwillbesunnyallday,chalk,andapolethatmakesashadow

Activities

1.Earlyinthedaypushtheendofastickintothegroundstraightup(orrelyonthepole).

2.Usetheotherstickorpenciltomarkthewholelengthofitsshadowandplaceastoneatthefarthestpoint.Oncementorpavedareas,usechalkasamarker.

3.Drawalinealongtheshadoweverycoupleofhoursthroughouttheday,andeachtimeplaceanotherstoneatitsfarthestpoint.

4.Discusswhenshadowsareshortest(middleoftheday)andlongest(early,lateintheday),howshadowswouldbedifferentatothertimesoftheyear,andhowshadowswouldbedifferentclosertoorfurtherfromtheequator.


49

Applyknowledgetosolarcooking

Whatyouneed

•Solarcooker(studentscanmake)

•Plasticbag

•Darkpot

Activities

1.Havestudentsexplainhowasolarcooker:

•Useslight

•Changeslighttoheat

•Transmits,reflects,absorbs,andconductsheat

•Insulatesfromheatloss

2.Havestudentsrelatetheconceptsabovetopartsofasolarcooker:

•Reflectorsaddextrasunlight

•Darkmetalabsorbslightandchangesittoheat

•Windoworbagtransmitslightandholdsairwhichactsasinsulation

•Etc.

Ideasforindependentstudy

1.Geography

•Comparetheamountofsunlightandrainfallindifferentpartsoftheworld

•Studytypesofcookingfuels,wheretheycomefrom,andtheireffectsontheenvironment

2.Socialstudies

•Explorecostsofcookingfuelsforhouseholds,andforgovernmentsthatmustimportfuels

•Explorecostsofpasteurizingdrinkingwaterandoftreatingdiseasescausedbyunsafewater

•Interviewhouseholdsaboutcookingfuelcosts,timespentcookingandgatheringfuel,andtheeffectsoffuelshortages(ifany)onfamilytime,healthandnutrition

50


3.Science

Exploreanddescribethefollowing:

•Theeffectsonnutritioniffamiliesareunabletocookfood

•Diseasesthatarespreadbygermsinwater

•Thehealtheffectsofsmokyair

•“Greenhouse”gasesandglobalwarming

Usingasolarcooker:

•Theeffectsoncookingtimeofdifferenttypesorquantitiesoffood,differentpots,etc.

•Compare/contrastcookinginlightanddarkpotsofequalsize

•Compare/contrastcookingwithandwithoutaplasticbag(inapanelcooker)

•Usingthermometers,measureandgraphwatertemperatureinasolarcookerthroughouttheday

•Measuredimensionsofthesolarcooker

4.Languages

•Translateinformationaboutsolarcookinginto(orfrom)anotherlanguage

5.Vocationalskills,business

•Buildasolarcookeranduseittobakefoodforsale

SECTION7ABRIEFHISTORYOFSOLARCOOKING

52


In1767French/SwissHoracedeSaussuresolarcookedfruitinaglass-coveredboxmadeofthreeglasspanes,twopineboxesandwoolinsulation.British

astronomerJohnHerschelusedaboxcookerinSouthAfricain1830.ThefirstrecordeduseintheUnitedStateswasbySamuelP.LangleywhileclimbingMt.Whitneyin1881.Inthe1860sMouchotinAlgeriafirstcookedwithacurvedconcentrator.CharlesAbbotmadeaboxwithcurvedmirroredframestofocusontoacontainerofmotoroil.Thisheatedto177ºC(351ºF)andallowedcookingintheeveningwithstoredheat.IntheUnitedStates,MariaTelkesresearchedseveralcombinationtypesintheearly1900s.Earlysolarcookerswereexpensiveandinconvenient.

Inthe1970sdisappearingtreesandgrowingfuelshortagesrekindledworldwideinterest.GovernmentsofIndiaandChinadevelopedandpromotedsolarboxandcurvedconcentratorcookers.IntheUSABarbaraKerrandSherryColedevelopedsimple-to-makeboxcookers,aswellassolarfooddryersandsterilizers.BobMetcalfhasandcontinuestoresearchMetcalfhasandcontinuestoresearchMetcalfsolarwaterpasteurizationandsharestheknowledgeinmanycountries.

Kerr,Cole,MetcalfandothersfoundedSolarCookersInternational(SCI)in1987tospreadsolarcookingbenefitstopeopleandenvironmentsworldwide.Todaymanyhundredsofengineers,educators,PeaceCorpsvolunteers,communitydevelopmentworkers,retirees,governmentworkers,Rotaryclubs,universities,religiousgroupsandrefugeeprogramsaresharingsolarskills.Asjustafewexamples,SERVEhasbroughtsolarcookingtothousandsinPakistan.TheUniversityofChile,withTeresaGuzman,PedroSerranoetal.,broughtsolarcookingtoVillaSeca,avillagewheremostfamiliessolarcookandasolarrestaurantisatouristattraction.

Severedroughtsinthe1990spromptedSCItorefinetheultra-simpleCooKitbyRogerBernard(France)andshareitworldwideandwithmorethan30,000refugeefamiliesinsun-richeasternAfrica.RotaryInternationalandGirlGuideshavebroughtsolarcookingtonumerouscountries.

Wecanallhelpspreadsolarcookingforabetterworldwithabrighterfuture.

BarbaraKerrandSherryCole

SOLAR COOKERS INTERNATIONAL (SCI) is a nonprofit,nongovernmentalorganizationwithheadquartersinSacramento,

California,USAandanofficeinNairobi,Kenya.Sinceitsfoundingin1987SCIhasspreadsolarcookingskillsandtechnologieswheretheyareneededmost.Over30,000familieshavebenefiteddirectlyfrom SCI’s field projects and countless others have used SCI’sresources to learnhow tomakeanduse solar cookers and teachotherstodothesame.SCIdependsonthesupportofitsmembersanddonorstocontinuewithitsvitalmission.Weinviteyoutojoinusinthiseffort.

SolarCookersInternational

191921stStreet,Suite101Sacramento,California95814-6827

UnitedStatesofAmerica

Tel:+1(916)455-4499Fax:+1(916)455-4498

[email protected]

Plans for Solar Cookers 58 Pages

Documents

Transcript of Plans for Solar Cookers 58 Pages