1.1 blowing in the wind - european union science...

COUNTRY: Version 19.04.2015 TEAM:

Editor:Mag.PeterHolub(DirectorEUSO2015)

THEANSWERIS

BLOWINGINTHEWIND

TASKSHEET

Challenge 1 28th of April 2015 Country: Team:

CHALLENGE 1 2 TASK SHEET

COUNTRY: Version19.04.2015final TEAM:

Challenge1consistsoffiveparts,whichcanbeworkedonindividuallyorasateam.

TaskA: 92MarksTaskB: 92MarksTaskC: 92MarksTaskD: 06MarksTaskE: 24Marks

Youhave4hourstocompleteChallenge1

• Labcoatsandsafetygogglesmustbewornalltimesinthelaboratory.

• Eatinganddrinkingisstrictlyprohibitedinthelaboratory.

• Disposableglovesareprovidedandshouldbewornwhileworkingwith

• chemicals.

Onlythefinalanswersheet(colouredpaper)andthesupplementedgraphswillbeassessed.

• Oncompletionofyourworkallpapersincludingscribblingpapermustbehandedin.NOTHINGmustbetakenfromthelaboratory.

• Allresultsmustbeenteredintotheanswersheet(colouredpaper).

• Graphsmustbehandedintogetherwiththeanswersheet.



TheStory

TheregionKlein-VirtulienissituatedintheSouthRimoftheAlps,800-1300 meters above sea level. 60% of the region’s electrical powerdemandissuppliedbyhydroelectricpower,andtheremaining40%isimported. In order to cover the increasing energy demand and toreduce the dependency on electricity imports, a new renewableenergygeneratingplantwillbebuilt.Thisplantwillnotonlyproduceenergybutwillalsohavethecapacitytostoreelectricenergy.

Themountainousterrain intheregionideallysuitstheconstructionofawindpowerplantwiththepossibilityoftwoenergystoragealternatives:

1. Aclassicalpumpstation2. Amodernelectrolysisplant(Power-to-Gas,P2G)

Prior to the actual power plant construction in Klein-Virtulien several objections have beenraised:

• TheVirtucreekthatwillfeedthepumpstationisoneofKlein-Virtulien’smostbiodiverserunningwaters.AccordingtoalocalenvironmentalinitiativethecreekishometoAstacusastacus subsp. virtuliensis,an endangered crayfish.Members of this local environmentalinitiative are concerned that the new power station will significantly alter the naturalhabitat of the crayfish and therefore lead to its extinction. The new power stationproponents deny the occurrence of Astacus astacus subsp. virtuliensis and refer to itsresemblancetonon-protectedspecies.

• Another local environmental initiative promotes the following argument against theconstruction of the pumped storage hydro power station: Near the planned storagereservoirlieslandfillfromanabandonedleatherfactory.Intheeventofafloodintheareathereareconcernsthattoxicwastecouldbeleached,especiallyhexavalentchromium.Inorder to test this possibility, landfill samples will have to be investigated for thedeterminationofpossibleCr(VI)contamination.

• A further local environmental initiative opposes the electrolysis plant in Klein-Virtulien,becausefromtheirpointofviewthecombinationofwindpowerandPower-to-Gasdoesnotprovidetherequiredefficiency.

In order to raise community awareness regarding the power station concerns, especially of theyouth,aninternationalcompetitionwilltakeplaceinKlein-Virtulien.

You, as a competing team, are asked to take on the role of evaluators and issue a jointrecommendation for the future power station. In order to do so, you will have to conductseveralinvestigationsandexperiments.



TaskAPleaseNote

Takecareoftheorderinwhichyoucompletethetasks.Beforestartingsections3.2and4youhavetosolve3.1andhandoverthecrayfishhand-out 3.1 to the laboratory assistant.è Only then you will receive further material tocontinue, table “Function”,adiagramshowing themorphologyofa crayfishaswellasacrayfishforidentification.

Material:

• crayfishextremities(leftorrighthalfofacrayfish)• Crayfishhand-outwiththeshapeofacrayfish• Glue• Forceps• Polystyrene-box• Magnifyingglass• Millimetrepaper• Ruler--------------------------------------------------------• 1Crayfish• Diagramshowingthemorphologyofacrayfish• Table“Function”

1. TheEcologyofAstacusastacussubsp.virtuliensis

Ecologicalconcepts:Biotope,HabitatandEcologicalniche

Innature,organismsarenotrandomlydistributed;theypreferspecies-specificdistinctsubareas.Inordertodescribetheirnon-randomspatialuse, termssuchasbiotope,habitatandecologicalnicheareused.Biotope: Is a topographical area with more or less uniform environmental conditions and ischaracterisedbyabiocenosis.Habitat:Theareaofthebiotopeoccupiedbyadistinctkindoforganism.Ecologicalniche:Representstheinteractionbetween

• thehabitat’sspatialdescription• theusedresources(nutrition,light,water,salinity,etc.)and• thespecies’reactiontoenvironmentalfactors

(Adaptedfrom:Sinsch,U.(2004).Studienbrief1:KonzeptederAutökologie.)UniversitätKoblenz-Landau.



ScientificinformationThe ecological demands of Astacus astacus subsp. virtuliensis correspondwith those of Astacusastacus.Bothliveexclusivelyinfreshwater,colonizeriversandstreamsandwarmlakesandpondswith steep banks in summer. However, Astacus astacus subsp. virtuliensis prefers a minimumwater depth of 40 cm. Thewater temperature in summermust be at least 11°C, the optimumtemperaturerangeisbetween19°Cand21°C.Theupperpessimum(=oppositeofoptimum)startsat24°C,at25°Cthecrayfishdie.Thetemperaturedropinautumnmarksthestartofthematingseason.The optimumoxygen content of thewater is between 6 and 12mg/L, 3.5mg/L is the absoluteminimum.A prerequisite for the colonization by this crayfish is a strong structuring of the benthic zone;Sufficient hiding places and resting placesmust be present (large stones, bankswith tree roots,cavesduginthebanks).Asmanycrayfishspecies,Astacusastacussubsp.virtuliensisiscrepuscularandnocturnal.Duringthedayitwithdrawsintherestingareas.Theyoungcanbeseeninshallowwater,wherethey can hide in between plants. Astacus astacus subsp. virtuliensis is an omnivore. Its dietcomprises algae, water plants, insect larvae, mussels, slugs and carrion. It “collects” its foodactively.1.1. Matchthedefinitions(leftcolumn)withthecorrectecologicalterms

(biotope,habitat,ecologicalniche)throughtickingthecorrectbox. ðAnswersheet

1.2. AstacusperformanceinresponsetowatertemperatureinsummertimeInSummer(beginningofJuneuntilmidSeptember)thewatertemperatureisanessentialfactorforthespeciesperformance,andthusfortheoccurrenceofAstacusastacussubsp.virtuliensis.

1.2.1 Draw a graph (bell-shaped curve) demonstrating the relationship between the stated

watertemperatures(minimum,optimum,maximum)versusspeciesperformance. ðGraphpaperNote: The species performance can take values from 0 (no individual survives) to 100 (optimalhabitatuse).1.2.2 Label the graph of 1.2.1 with the characteristic temperature range and temperature

points/temperature ranges (minimum, maximum, optimum, pessimum). Annotate thegraphandaddalegend.

ðGraph



2. PossibleeffectsofapumpstationonAstacusastacussubsp.virtuliensisScientists found that the erection of a pump station may change some ecological factors forAstacusastacus subsp. virtuliensis. Examine, if the constructionofapumpstationwill influencethepopulationofAstacusastacus subsp. virtuliensis, using thegiven twographson theanswersheet“Averageoxygencontentintheriverpermonth”and“Averagetemperatureintheriverpermonth”2.1. Identifyareasinthegraphsrepresentingecologicalfactorsthatcanleadtoextinctionofthe

crayfishpopulation.Mark,whatyouidentified.2.2. Mark optimal areas for Astacus astacus subsp. virtuliensis for temperature and oxygen

contentinsummerwithinthegraphs.3. FunctionalmorphologyofcrayfishReminder:Takecareoftheorderinwhichyoucompletethetasks.Beforestartingsection3.2and4youhavetosolve3.1andhandoverthecrayfishhand-out3.1tothelaboratoryassistant.3.1 On the provided crayfish hand-out, arrange the crayfish extremities from the glass

containerinthecorrectorder.Selecttheappropriatehand-out,leftorright! ðcrayfishhand-out

Allextremitiesmustbegluedontothecrayfishhand-out!!

Hint: The picture in the hand-out is taken from the ventral side. Some limbs are hard todistinguish. Ifyoucannotdeterminetheirexactorder,position themasagroup.Theveryexactpositioningoflimbsyieldsonly2marksintotal.Onceyouaresatisfiedwithyourlayouthandoverthecrayfishhand-outtothelaboratoryassistantwhowillnowtakeapicture.



3.2 Match each extremity to its main function (multiple assignments are possible, butmaximallythreeassignmentsperextremityareallowed).àThetable“Function”

ðAnswersheet

Eachboxmustshoweitheracrossorazero:”X“forcorrect,”0“forincorrect. Function:• A=Graspingobjects/foodandusedfordefence/attack• B=Processing/manipulation(breaking,chewing,handling)offood• C=Reproduction/broodcare• D=Sensoryperception

o D1=chemicalsenseo D2=tactilesenseo D3=balance(equilibrium)

• E=Movemento E1=pacingo E2=swimming

4. Crayfishidentification

Thistaskcanonlybesolvedonceyouhavecompletedtask3.1andhandedincrayfishhand-out3.1tothelaboratoryassistant.OnlythenyouwillreceivethecrayfishforidentificationandtheDiagramshowingthemorphologyofacrayfishfromthelaboratoryassistant.

UsingthekeyverifyifthepresentcrayfishisAstacusastacussubsp.virtuliensis.

A Cephalothorax 7 Jointofthecheliped

B Tail 8 Rostrum

1 Antenna 9 Postorbitalridge

2 Anteriorcarapacae 10 Spines

3 Posteriorcarapacae 11 Cervicalgroove

4 Abdomen 12 Areola

5 Telson13 Transversebandsacrossabdominalsegments

6 Cheliped

4.1 Tickthestatementsonthekeyinthegreycolumnthatleadtotheidentificationofthepresentedcrayfish!

ðAnswersheet



5. Theoreticalquestions5.1. Whichofthestatementsarecorrect

WhichareincorrectTickyourchoice.

ðAnswersheet

6. EvaluatethesituationofconstructingapumpstationinKlein-Virtulien

WithregardtothesuspectedAstatacusastacussubsp.virtuliensispopulation,evaluatewhethertheconcernsofthecitizen’sinitiativesarejustified.Usetheinformationfrom

• “TheecologyofAstacusastacussubsp.virtuliensis“(1)• your insights from “The possible effects of a pump station on Astacus astacus subsp.

virtuliensis”(2)• aswellasyourresultsfrom“Crayfishidentification”(4)• Assesstheeffectsofbothalternativepowerplantstationsonthecrayfishpopulation.

Assessandsummariseyourassessmentinthetable. ðAnswersheet.



TASKBIntroductionIncloseproximitytotheproposedreservoir lies landfill fromanabandoned leatherfactory.Theopponents have raised some concerns due to possible leaching of hexavalent chromium, if theareawastoflood.TheprojectmanagersarelookingintotheseallegationsandwillacquirelandfillsamplestoconductaninvestigationofthecontaminationwithCr(VI).AsachemistryexpertyouhavebeenaskedtoextractCr(VI)fromthesesamplesaccordingtoDINS4 and to determine the Cr(VI) concentration spectrophotometrically. Calculate the expectedpollutionfromchromiumandassesspossibleenvironmentalconsequences.Cr(III) is an essential trace element, whereas Cr(VI) is carcinogenic. In compounds chromiummainlyappearswiththeoxidationstate+IIIand+VI.Cr(VI)isfarmoretoxicthanCr(III)duetoitsability to penetrate cell membranes. Once in the cell it acts as a strong oxidising agent, thuscausingoxidativedamageinthebody.One method to analyse Cr(VI) spectrophotometrically is based on its reaction with 1,5-diphenylcarbazid(DPC)inacidsolution.

Fig.1:ReactionofdichromatewithDPCinacidsolution

This reaction is very sensitive, thus even slight traces of Cr(VI) can be detected. The reactionresults in the formationofapurplecomplex (seeFig.1), thecolour intensityofwhich isdirectlyproportionaltotheconcentrationofCr(VI).WiththiscolourationtheCr(VI)concentrationcanbe



measured at 550 nm. The absorption is a function of the wavelength of the light and theconcentrationofthesample.Withinacertainconcentrationrange,therelationbetweenconcentrationandabsorptionislinear.ThisrelationisdescribedwithLambert-Beer’slaw:

A=a*c*dA=theabsorption,measuredbythespectrophotometera=themolarabsorptioncoefficientofthesubstance(alsoknownasɛ)c=themolarconcentration(mol/L)d=thedistancethelighttravelsthroughthesample(pathlength,simplified:thethicknessofthecuvette)

Inthistask,Awillbemeasured,dcanbefoundinthelistofmaterials,acanbecalculatedfromthecalibrationcurveandwiththisinformationccanbecalculated.DesignandfunctionofthespectrophotometerusedforthistaskisshowninFig.2andFig.3

Fig.2:SpectrophotometerUV-1600PC

Fig.3:Schematicdrawingofaspectrophotometer(courtesyofMichaelaDeRouw)

[1]Lightsource [2]Entranceslit [3]Prisma [4]Exitslit [5]Cuvettewithsample [6]Entranceslit [7]Detectorwithdisplayingdevice



In thespectrophotometerathand, lightwithawavelengthof550nmpasses throughacuvettewithapathlengthof1cm.ThewavelengthcorrespondstothemaximumabsorptionoftheCr(VI)solution,whichhasbeendeterminedbasedonanabsorptionspectrum(seeFig.4).

Fig.4:AbsorptionspectrumofthecomplexfromCr(VI)andDPC

The cuvette contains the solution that should be investigated. The light passing through thecuvette is partially absorbed and a detector records the intensity of the light that reaches theoppositeside.

Listofmaterials Listofchemicals• Paper,graphpaper,ruler,rubber• Calculator• Periodictable• Permanentmarker,pencil,sharpener• Pistonpipette100μL(adjustable)• Pistonpipette1000μL(adjustable)• Pipettetips(blueandyellow)• Containerforusedtips• Testtubes15mL(Falcon)• Testtuberack• 1cmcuvettesforthe

spectrophotometer• Papertowels• 1spectrophotometer(for3groups)

• Ultrapurewater• Cr(VI)stocksolutionforcalibration

(28.29mg/LdipotassiumdichromateK2Cr2O7),labelled“Cr(VI)“

• Sulfuricacid0.5M,labelled“0.5MH2SO4“

• Reagentsolution(120mg1,5-diphenylcarbazidin50mLacetone),labelled“DPC“

• 5solutions(eluatesfromsoilsamples)withunknownCr(VI)concentrations,labelled“E1“,“E2“,“E3“,“E4“and“E5“

• ReferencesolutionwithaknownCr(VI)-concentration(4.00mg/L),labelled“Ref“



Instructions:Soilsamples,fromtheformerlandfillsite,havebeenacquiredfromfivedifferentlocations.Duetolackofsufficienttime,theextractionhasalreadybeencompletedforyou:a100gsoilsampleandonelitreultrapurewaterwereshakenupsidedownfor24hours.Onyourplaceyoucanfindthesoilsamplesaseluates(E1-E5),ofwhichtheCr(VI)concentrationhastobedetermined.In order to determine the concentrations of each of the five samples, you must first plot acalibration curve. Therefore, you need the absorption values of the solutions with knownconcentrations. These solutionsmustbeprepared from the stock solution (labelled “Cr(VI)”) byappropriatelydilutingit.1. CalculatetheconcentrationofCr(VI)inthestocksolutioninmg/L. ðAnswersheetBefore you continue, the accuracy of the result has to be confirmed by a lab assistant on theanswersheet!

2. DeterminationofacalibrationcurveandspectrophotometricmeasurementInordertodetermineacalibrationcurve,fivedilutedsolutionswithaconcentrationrangingfrom25-250µg/Lhavetobepreparedfromthestocksolution.YouwillfindtheconcentrationsneededforthefivesolutionsinTable1onyouranswersheet.2.1. Calculate the volume of stock solution required to prepare 10 mL of the respective

solutions.RecordthevaluesinTable1! ðAnswersheet2.2. Preparationofcalibrationsolutions

a. Marksix15mLtesttubeswith1-6b. Add 2 mL sulfuric acid (marked “0.5 M H2SO4”) in each test tube with a piston

pipette.c. Add0.2mLofthereagentsolution(marked“DPC”)ineachtesttubewithapiston

pipette.d. Using your calculation from Table 1 on the answer sheet, measure and add the

appropriatevolumeofstocksolutiontotesttubes2-6,respectively.e. Filleachtesttubeuptothe10mLmarkwithultrapurewater.f. Closetesttubesandmixthoroughly.



2.3. Preparationofsamplesandreferencesolutiona. Markthenextsixtesttubeswith7-12b. Add 2 mL sulfuric acid (marked “0.5 M H2SO4”) in each test tube with a piston

pipette.c. Add0.2mLofthereagentsolution(marked“DPC”)ineachtesttubewithapiston

pipette.d. Pipette250µLofeluateE1intotesttube7,250µLofeluateE2intotesttube8,and

continuethisproceduretotesttube11,andofreferencesolutionintotesttube12.SeeTable2ontheanswersheet.

e. Filleachtesttubeuptothe10mLmarkwithultrapurewater.f. Closetesttubesandmixthoroughly.

2.3.1. Calculatethedilutionfactorfortheeluates.Theresultofthiscalculationhastobeconfirmedbeforeyoucontinuewiththespectrophotometermeasurements(labassistant’ssignatureonanswersheet). ðAnswersheet

2.4. Spectrophotometermeasurement

a. Transferthepreparedsolutions(testtubes1-12)intothecuvettes(useatleast¾ofthetotalcuvettevolume).Donotforgettolabelthecuvettesappropriately.

b. Informthelabassistantthatyouarereadytousethespectrophotometer.Sincethreeteamsshareonespectrophotometer,youmayhavetowaita fewminutes foryourturn. In themeantime, you could study the function of the spectrophotometer oranswer“7.ConcludingQuestions”!

c. Completethespectrophotometermeasurementswithin10minutes.

Instructions for the spectrophotometer: Put cuvette 1 (blank) into thespectrophotometer.Thesmoothsidemustfacethelightsource.Closethelidandthenpress “Zero”. Then, place cuvette 2 into the spectrophotometer, close the lid, andrecordtheabsorption(inTable2).Repeatwithcuvettes3-12.

2.4.1. RecordthemeasuredabsorptionsinTable2. ðAnswersheet



3. Plottingagraph

3.1. Plottherecordedabsorptionvaluesusingacoordinatesystem. ðGraphpaper!• Theabscissashouldshowtheconcentrationinµg/Landtheordinateshouldshow

thecorrespondingabsorptions.• Plottheregressionline.• Fromthisplot,determineandmarktheslopeofthelineandtheintercept.• Entertheabsorptionvaluesoftheeluatesintothecoordinatesystemandmarkthe

correspondingconcentrationsontheabscissa.

Handinyourgraphpapertothelabassistant.

Forallfurthercalculationsyouwillreceivevaluesfortheslopeandintercept.

4. Calculatetheconcentration(µg/L)ofeluates1-5andthereferencesolution.RecordthevaluesinTable3. ðAnswersheet

5. CalculationofCr(VI)concentrationofsoilsamples

5.1 Calculatetheoriginalconcentrations(mgCr(VI)/kg)ofthesoilsamples.Usetheconcentrationvaluesfrom4.Takethedilutionsintoaccount(seeconfirmedresultsofsection2.3.). ðAnswersheet



6. Cr(VI)pollutioninthesoilandthereservoir

If theareaof the former landfill gets flooded,allCr(VI)present in thesoilwillbedissolvedandthereforefoundinthereservoirwater.

Answer6.1.to6.4. ðAnswersheet

6.1 CalculatetheaverageCr(VI)contentinthesoil(mgCr(VI)/kg).

6.2 UsetheaverageconcentrationtocalculatehowmuchCr(VI)(kg) ispresent, ifthelandfillcontains2000twaste.

6.3 What is the concentration of Cr(VI) (µg/L) that can be expected in the reservoir if thelandfillisfloodedwith80millionm3waterandalltheCr(VI)isleached?

6.4 Fromanecologicalpointofview,shouldthereservoirbebuilt?(limitofCr(VI)indrinkingwater:50µg/L)

7. Concludingquestions

OntheAnswersheettickyesornointhecorrespondingcolumns. ðAnswersheet



TASKC

1. MeasurementsonamodelofawindmachineUsingamodel,investigatesomeofthephysicalpropertiesofawindmachine.

1.1. MeasurementofairspeedDeterminethespeedoftheairgeneratedbythewindmachine.Materials:

• Windmachinemountedonastand(Fig.1.1.)• Windmaster(anemometer)mountedonastand• Ruler

Fig.1.1WindmachineProcedureMountthewindmachineandtheWindmasteratadistanceof0.4mfromeachother.ThecenteroftheairoutletandoftherotatingcupsoftheanemometershouldbeatthesameheightandthewindmachineshouldpointexactlyindirectionoftheWindmaster(Fig.1.2).



Fig.1.2:SetUp

Fig.1.3:RotaryswitchfordifferentspeedsofairTheairspeedcanbecontrolledbytherotaryswitch(seeFig.1.3).Caution:Thedifferentlevelsarenotmarkedbynumbersontheactualdevice!Switchonthewindmachineatthelowest level, level1.Let itrunfor15seconds.SwitchontheWindmasterandletitrunforabout1minute.Observethedisplayandmakeanoteoftheaveragevalue(AV)andofthemaximumvalue(MX),seeFig.1.4.

1 2

3

4

5



Fig.1.4Windmaster. Shownonthedisplayfromtopdown:currentvalue,maximumvalue (MX),averagevalue(AV).Allvaluesaremeasuredinm/s.Writetheaveragevalue(AV)andmaximumvalue(MX)ontheanswersheet(Table1.1.1).SwitchofftheWindmaster.Change thewindmachine to level2andswitchon theWindmasterafter15seconds.Make thesame measurements as before and write the values on the answer sheet. Switch off theWindmaster after the measurement. Continue the same procedure for levels 3-5 of the windmachine.1.1.1. CompleteTable1.1.1withthecorrespondingvalues! ðAnswersheet1.1.2. Drawingthediagram“Levelsofthewindmachineversusairspeed”DrawadiagramusingthemeasuredvaluesfromTable1.1.1 ðmillimeterpaperMakeanappropriatescaleforthey-axis(airspeedinm/s).Drawpointsfortheaveragespeeds.Themaximumvaluesshouldbetheupperlimitsoftheerrorbars.Assumethattheerrorbarsaresymmetricalaroundtheaveragevalue.Drawtheerrorbars.Besuretousetheprovidedmillimeterpaperandpasteyourdiagramontheanswersheet!

1.2. Measurementsoftheoff-loadvoltageswithvariousrotorbladesAcharacteristicparameterofthepowergeneratedbywindmillsistherespectiveoff-loadvoltage.It is defined as the voltage that is generatedwithout any load on the generator.Measure thisvoltagefordifferentrotorbladesinordertofindthemostefficientblade.



Materials:• Propeller–16cmdiameter• Propeller–18cmdiameter• Propeller–20cmdiameter

(seeFig.1.5)• Twocrossedpropellers–16cmdiameter• Invertedpropeller–16cmdiameter

(seeFig.1.6)• Multimeter• Cables• Windmachine• Generator• Standforthegenerator

Fig.1.5:Propellers16cm,18cm,20cm.(Inscriptiononthebladeshouldbedirectedtowardthegenerator)

Fig. 1.6: Two crossed propellers, 16 cm(inscription is directed toward the generator),and inverted propeller (inscription is directedtowardthewindmachine).



ProcedureThedistancebetweenwindmachineandpropellerisagain0.4mthroughoutallmeasurementsinthispart(Fig.1.7).

Fig.1.7:Windmachine(left)andpropeller(right).The propeller is mounted on the generator using the white piece of plastic (Fig. 1.8). Themultimeterisconnectedtothegeneratorbycrocodileclips.

Fig.1.8:Propellermountedonthegenerator.Measure theoff-load voltagesU0 for all propellers and for all levelsof thewindmachine. Starteachmeasurementwithonetypeofpropelleratlevel1,andthewindmachineshouldrunforatleast15secondsoneachlevel.Sincethevoltagevaluesdisplayedmayfluctuatethroughoutyourmeasurementsyouwillhavetocarefullyobserveandmakeadecisionontheaveragevalue.InsertthevoltagevaluesrecordedintoTable1.2 ðAnswersheet

1.3. OutputpowerofvariouspropellersThe voltage alone is not a definitive characteristic of a wind generator.More importantly, thepower that can be produced when a load is attached to the generator must be taken intoconsideration.Thepowercanbecalculatedusingvaluesofthecurrentpassingthrougharesistorandthecorrespondingvoltage.



Materials:• Windmachine• Generatorwithdifferentpropellers:16,18,20,16/16,16(inverted)• Twoconnectioncables(black,red)fromthegenerator• Multimeterwith4cables.• Calculator• Material

Thedistancebetweenthewindmachineandthepropellerisagain0.4m.Thegeneratorshouldbeconnected to the multimeter. Connections for the measurements of current and voltage areparalleltothegenerator(seeFig.1.9).

Fig.1.9:Windmachine,propellerandconnectionstothemultimeter.Switchthewindmachinetolevel5.Theresistance(“LoadLast“onthebox),shouldbevariedfrom1Wto200W(sevenlevels).• InsertthemeasuredvaluesofvoltageandcurrentintoTables1.3. ðAnswersheet• Calculatethecorrespondingpowerandinsertthesevaluesintothetable.

ðAnswersheetCaution:Thevaluesmaynotbestrictlyconstant–useaveragevalues.



• Drawthevaluesforthepowerinthediagrams. ðAnswersheet!

2. MeasurementsonamodelofaPowerToGasfacilityTheconversionofelectricpower togas isapossibility for storingenergy.Water is split intohydrogen and oxygen through electrolysis and electrical energy is transferred to chemicalenergy. Later on, a fuel cellmay enable the inverse process, the transfer from chemical toelectricalenergy.

2.1. ElectrolysisInvestigatetheprocessofelectrolysis.Howmuchelectricalenergyisneededtoproduceacertainamountofhydrogen?Howhighistheefficiencyofthismodel?Material

• Windmachine• Generator• Propeller–16cmdiameter• Multimeter(measurethevoltageandthecurrentattheelectrolyser).Adjustment(electric

load):ShortCircuit• Electrolyser:Fillitwithdistilledwater• Cables• Stopwatch

1

2

3



Fig.2.1:Circuitdiagram:V,A,andRarepartofthemultimeter(1);electrolyser(2); fuelcell (3).The cables to the generator are not shown. They should be connected to the poles of theelectrolyser(seetext).ProcedureAssemblethemodelaccordingtoFig.2.1.Thefuelcell isalreadyconnectedtotheelectrolyser (hoseswithshut-offvalves), itwillbeusedlater(2.2).Hint:Connectfirstthecircuitgenerator–electrolyser–multimeter(measurementofthecurrent).Then establish themeasurement of the voltage. Pay attention to the correct polarity (+ of thegeneratorhastobeconnectedto+oftheelectrolyser).Beforeyoucontinue,thecircuithastobeconfirmedbyalabassistantontheanswersheet.

2.1.1. Measurementofthepowerattheelectrolyserwithdifferentairspeeds

Thewindmachineshouldbemounted0.2m(halfoftheusualdistance!!)infrontofthepropeller.MeasurethevoltageandcurrentforeachofthefivelevelsofthewindmachineðAnswersheet(Itshouldrunforabout1minute,takeaveragevalues).Calculatethepowerattheelectrolyser.InsertthevaluesintoTable2.1.1 ðAnswersheet

2.1.2. Productionofhydrogen

Usethesameequipmentasbeforeanddeterminehowmuchenergyisneededtoproduce10mlofhydrogengas.ProcedurePayonlyattentiontothecolumnofhydrogengas.Startatzerovalue(ifthevalueistoohigh,thenreleasesomegas).Oncetheproductionofgasstartsbesuretoalsostartthestopwatch.Stopthestopwatchonce10mlofhydrogengashasbeencollected.Measurethevoltageandcurrent(averagevalues)andthetimeneededfortheproductionof10mlofhydrogen.Recordthevaluesontheanswersheet. ðAnswersheetCalculatetheelectricalenergythatisneededbytheelectrolysertoproduce10mlofhydrogen,usingthepowerandthetime.Insertyourresultintotable2.1.2 ðAnswersheet

2.1.3. Efficiencyoftheelectrolysisprocedure

Thecaloricvalueof1m³hydrogenis10.7MJ.Calculatetheefficiencyoftheapparatususingtheresultfrom2.1.2!Insertyourresult ðAnswersheet



2.2. FuelcellAfuelcellproduceselectricalenergyfromchemicalenergy(hydrogen).Material:

• Electrolyserwithhosesandshut-offvalve• Fuelcell• Multimeter• Cables

Procedure

Thereshouldstillbeavailable10mlhydrogengasandatleast5mloxygengasintheelectrolyserfrom the last experiment. If not, you will have to use the wind machine-propeller-generator

systemtoproducetherequiredamountofgas.Fig.2.2:Circuitdiagram:V,A,andRarepartofthemultimeter(1);electrolyser(2); fuelcell (3).Themultimetershouldnowbeconnectedtothefuelcell.Closea circuitwith the fuel cell, 3-Ohm resistor andAmperemeterof themultimeter (Fig. 2.2).Hint:First connect in series the fuel cellandAmperemeter (payattention to thepolarity).Thenattachthevoltmeterinparalleltothefuelcell.

2

3

1



2.2.1. Releasedelectricalenergyofafuelcell

Determinethetimeittakestotransfer10mlhydrogenbackintoelectricenergy.Calculatetheaverageamountofelectricalenergywiththemeasuredvaluesofvoltage,current,andtime.Insertthesevalues ðAnswersheet

2.2.2. Efficiencyofthefuelcell

Determinetheefficiencyofthefuelcellbycomparingthecaloricenergyof10mlhydrogenandthereleasedelectricalenergy. ðAnswersheet

3. ComparisonofrealisticfacilitiesThe following calculations should give an answerwhether a planned pump storage facility or aPowertoGasfacilityarebestsuitedforstoringelectricenergy.Cantheenergyproducedbyawindpowerplantbestoredbyeachfacility?Whichfacilityhasbetterefficiency?

3.1. Powerofaplannedwindpowerplant

The power, which can be taken out of a wind of speed v by a modern wind turbine, can becalculatedbythefollowingformula:

AvcP Betz ⋅⋅⋅= 3

2ρ

P:powerinWattcBetz:powercoefficient,modernfacilitieshaveapproximatelycBetz≈0.5r:densityofair(r=1,39kg/m³)v:speedofwind(m/s)A:areacoveredbytherotatingrotorblades(m²)Thewindpowerplantshouldconsistof10windturbineswithrotorbladesof35mlength.3.1.1. Calculatethepowerofthiswindpowerplantassumingawindspeedof40km/h.GivetheresultinunitsofMegawatt(MW). ðAnswersheet3.1.2. Calculatetheenergywhichisproducedinoneday(MWh)undertheseconditions. ðAnswersheet

3.2. Powerofaplannedpumpstoragefacility

Theplannedconstructionhasadropheightofwaterof250m.Themaximumflowrateis50m³persecond.Thepowercanbecalculatedfromthepotentialenergyofthewater(E=m.g.h).



The same flow rate (50m³) isalsomanageable inpumpingwaterup toaheightof250m.Theefficiencyofthisprocedureis60%,i.e.60%oftheincomingenergycanbestoredinthewater.

3.2.1. Powerofthefacility

Calculatehowmuchpowerthispumpstoragefacilitycansupply? ðAnswersheet3.2.2. Energyinthesystem

Calculate:Howmuchwatercanbetransportedupeachday,assumingmaximumpowerofthewindpowerplant? ðAnswersheet

3.2.3. Totalefficiency

If the water is released and flows through the turbine, the efficiency of generating electricalenergyis80%.Calculatethetotalefficiencyofthepumpstoragefacility ðAnswersheetHint:Bothefficiencies,pumpingupwaterandreleasingit,havetobetakenintoconsideration.

3.3. DimensionsandefficiencyofaplannedPowertoGasfacility

3.3.1. Electrolysis

Theplannedfacilitycanproducehydrogengasfromelectricalenergywithanefficiencyof70%.Calculatetheamountofhydrogengasthatcanbeproducedeachhour,ifthewindpowerplantrunsatfullpower. ðAnswersheetHint:Usetheresultsof3.1.

3.3.2. TotalefficiencyofthePowertoGasfacility

Amodernfuelcellhasanefficiencyof50%.Calculatethetotalefficiencyoftheelectrolysis-fuelcellfacility. ðAnswersheet

3.4. Comparisonofbothfacilities

You,asanevaluator,nowhavetocompareandjudgethetwofacilities.Asconstraints,youhavetoconsider:Thecapacityoftheupperreservoirofthepumpstoragefacilityis80millionm³atmost.Thegasstorageoftheelectrolysisfacilityhasacapacityof2000m³hydrogenperhour,atmost.Whichofthesetwofacilitiesdoyourecommendforconstruction?InsertyourresultsanddecisioninTable3.4! ðAnswersheet



TaskDRecommendationofthescienceteamforthepowerstationconstructioninKleinVirtulien1. Summarizeyour resultsasa team in the table“Findings” tohelpyoucometoacommon

statementintable“Recommendation”! ðAnswersheet

2. Indicateyourteamrecommendationinthetable“Recommendation”! ðAnswersheet

TaskEFactsabout....Evaluatethestatementsinthetable”Factsabout….“! ðAnswersheet

4 Crayfish identification: Dorsal diagram of a stereotyped crayfish



Challenge1TaskA

Thetable“Function”

Extremity

Function Marks

A B C D E

D1 D2 D3 E1 E2

1

2

3

4

5

6

7

8

9

10

11

12 13

14

15

16

17

18

19



Challenge1TaskA

72correctticks 10points lessthen40correctticks

0points

40correctticks

0,4points

between41and72correctticks 0,3pointsforeachcorrecttick

Subpoints Points40 0.441 0.742 1.043 1.344 1.645 1.946 2.247 2.548 2.849 3.150 3.451 3.752 4.053 4.354 4.655 4.956 5.257 5.558 5.859 6.160 6.461 6.762 7.063 7.364 7.665 7.966 8.267 8.568 8.869 9.170 9.471 9.772 10.0



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1.1 blowing in the wind - european union science...

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