Micro‐hydroSummarySeptember2011

PreparedbyLukeHutchinson,LinkdEnvironmentalServices

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TableofContentsMicro‐hydroSummary ................................................................................................................................. 1

1. Introduction........................................................................................................................................... 3

2. TechnicalOverview................................................................................................................................ 3 2.1 ConfigurationOptions ......................................................................................................................................... 4

3. LocalPotential ....................................................................................................................................... 6

4. RegulatoryFramework .......................................................................................................................... 7

5. BarrierstoImplementation ................................................................................................................... 8

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1. IntroductionHydropoweristhemeansofusingtheflowofwater,whichismovingduetogravitationalforcetodriveturbinesthat

generate electricity. The scale of installation can vary from as little as a few kilowatts to hundreds ofmegawatts.Hydropowermayincludetidalandwavetechnologies,howeverthiswillnotbecoveredinthistechnologyreview.

Today, the development of large scale hydro operations is not preferred and resisted due to the potential forupstream flooding which can destroy agricultural areas, animal habitats and displace communities in the affectedareas1. Micro‐hydro presents an alternative option with environmental impact on a far minimal scale because

implementationispossiblecoupledtootherusesofwater(e.g.bulkwatersupply,irrigation,floodcontrol,etc)2.

Micro‐hydro power plants, involving small dams, pumps or water mills, can provide a means of electricity tocommunities that cannotbeconnected to thenational grid.With capacityof10kWto10MWthe technology can

provide electricity in remote areas in a very effective way with a lifespan of 30 years ormore. Furthermore, it isestimatedthatforevery1MWofhydropowerinstalled,twopermanentjobsarecreatedinthehydropowerindustry2.

Internationallynosizeterminologyisstandardised,thefollowingisanindication2:

• Pico lessthan20kW• Micro 20kWto100kW• Mini 100kWto1MW

• Small 1MWto10MW

Macrohydroconventionalinstallations:greaterthan10MW.Forgeneralpurposesmicro‐hydrowillbeusedtorefertogenerationlessthan10MW.

2. TechnicalOverviewA fundamental design requirement for economic sustainability is the efficient use of the water resource.Modern

turbinetechnologywillallowupto95%oftheenergyavailablefromwatertobeconvertedintoelectricity3.

The power output of a hydropower plant is proportional to thewater flow rate and the head (the height throughwhichthewatermustdescendbeforegoingthroughtheturbine).Theflowrateisthequantityofwaterflowingpasta

point inagiven time ‐ typicallymeasured in litresper secondor cubicmetresper second.Thehead is theverticalheight,inmetres,fromtheturbinetothepointwherethewaterenterstheintakepipeorpenstock.

Thepotentialpowercanbecalculated4asfollows:

Theoreticalpower(P)=Flowrate(Q)xHead(H)xGravity(g)=9.81m/s2

WhenQisincubicmetrespersecond,Hinmetresandg=9.81m/s2)then,P=9.81xQxH(kW)

However, energy is always lostwhen it is converted fromone form toanother.Powerwillbe lost in thepenstock

carryingthewatertotheturbine,duetofrictionallosses.Withcarefuldesign,thislosscanbereducedtoonlyasmallpercentage.

Example:Aturbinegeneratorsetoperatingataheadof10metreswithflowof0.3cubicmetrespersecond

willdeliverapproximately,(9.81x0.5x0.3x10=)18kW.

1DepartmentofEnergyPhilippines‐http://www.doe.gov.ph/ER/Hydropower.htm

2BaselineStudy:Hydropower inSouthAfrica,Department ofMineralsandEnergy,CapacityBuilding inEnergyEfficiencyandRenewableEnergy(CaBEERE)‐2002

3HErdmannsdörfer,SmallDecentralizedHydropowerStations‐AFutureforRuralAreaswithoutDieselPower,Germany‐EnergyPartnerforAfrica

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The type of energy conversion technology required is related to the head classification. Hydro power conversion

occurs through the use of either impulse or reaction turbines. Impulse turbines convert the kinetic energy whilereactionturbinesconvertthepressureenergyintomechanicalenergy.Reactionturbinesworkbyfullyimmersingtheturbineblades inwaterandmustbebuilttowithstandtheoperatingpressure,turbineexamplesincludeFrancisand

Kaplanturbines.Impulseturbinesmakeuseofahigh‐speedjetofwaterstrikingthebucketsmakinguseofthewatersmotion,turbineexamplesinclude:Pelton,Turgo,cross‐flowturbines4.

Figure1–Typesofturbines,reactionatleft,impulseatright.

2.1 ConfigurationOptions

Run‐of‐river

Themajorityofmicro‐hydropowerplantsarerun‐of‐river schemes.Thistypeofhydropowerplantoperatesunderlowheadand ismainlybuilt inrivervalleys.Electricity isonlygeneratedwhenwater isavailableandwillstop if the

flowfallsbelowacertain level.Asaresultsmall independentschemesmaynotalwaysbeabletosupplyelectricity,unlesstheyaresizedsothatthereisalwayssufficientwater.

Themaincomponentsofarun‐of‐the‐rivermicro‐

hydroschemeareshownintheillustrationbelow.This typeof setup requiresnowater storagebutinstead diverts some water from the river along

the side of a valley to be ‘dropped’ into theturbineviathepenstock.Therearevariousotherconfigurations which can be used depending on

thetopographicalandhydrologicalconditions,butall adopt similar general principles andmethodologies.

Figure2:Layoutofatypicalmicrohydroscheme5

4Onlineresource‐http://www.hydro‐turbines.com/id74.html

5Micro‐hydroPower,PracticalAction–TechnologyChallengingPoverty

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Damwalls

Damwall hydropower schemes are usually not implemented for small ormicro‐hydro due to financial constraints,however; this configuration is viable if such dams have already been constructed6. Themain issue is how to linkheadwaterandtailwaterbyawaterwayandhowtofit theturbine inthiswaterway.Thetwoconfigurations inthis

casearetoplacetheturbineatthebaseofthedamifachannelcanbeconstructed,thealternativeisasiphonintakeasshownbelow.

Figure3.Siphonintakeconfigurationwiththeturbineplacedattheapexofthesiphon.

WaterInfrastructure

Insomeinstancesthereistheopportunitytoharnesstheenergycontainedinthebulkwatersupplyanddistributionsystem,oneexample is constructingahydropower facilitywithin irrigation canals.Anotheroption is to integratea

turbineintothedrinkingwaterinfrastructurebetweenreservoirandthewatertreatmentplant.Insomecasesplantshavespecialvalvestodissipatethekineticenergyandthereisanopportunitytoconvertthisenergyintoelectricity.

6GuideonHowtoDevelopaSmallHydropowerPlan–ESHA2004

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3. LocalPotential

Figure4:AreaswithmicrohydropotentialinSouthAfrica(DME,Eskom,CSIR,2001)

Thehydropowerpotentialhasbeenshowninthe“BaselineStudyonHydropower inSouthAfrica”(CaBEERE,2002–anassessment conductedby theDME) that there existsa significantpotential fordevelopmentofall categoriesofhydropower in the shortandmedium‐term in specific areasof the country. The imagebelow showsall areaswith

hydropotentialand it isevidentthattheEasternCapeandKwaZulu‐Natalprovinceshold significant capacity–andnotably,withthebestpotentialforthedevelopmentofsmall,hydropower(lessthan10MW).

Furthermore, the Eastern Cape province (particularly in the area of Transkei) is identified as potentially themost

productiveareasforhydro‐electricdevelopmentinSouthAfrica.InvestigatingthepotentialintheLowerOrangeriverforhydropowersetup inseriesortandem,showsthatsome12hydro‐electricplantscanbe installed inseries,eachsitehavingapotentialoutputofbetween6MWand25MW7.TableXshowstheavailableandpotentialofhydropower

inSouthAfrica.

Another study indicates that there are 3500 – 5000 potential sites for mini/micro hydro electric power plantsidentifiedalongtheeasternpartsofthecountry8.

7Clackson,E.(2002).Refurbishmentandupgradingofexistinghydro‐powerinstallations.Personalcommunication,Nelspruit,Mpumalanga,July

8BBarta,HydropowerPotentialinSouthernAfrica,TradersIssue20,November2004‐February2005

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Table1:TotalformacroandsmallhydropowerinSA‐excludingpumpstorage(CaBEERE,2002).

JobCreation

Theshort‐tomedium‐termpossiblehydro‐electricityproduction isestimatedatsome450GWh/year,dependingontheloadfactoradopted.Themedium‐termpotentialforjobcreationonlyfromthedevelopmentofmicrohydropowerschemesisestimatedatabout3,000jobs,withsome1,100jobsonapermanentbasisintheoperation,manufacturing

andadministrationofhydropowerdevelopment9.

DuetothepresenceofsizableandestablishedminingindustryinSouthAfrica,thereisalargeindustrialsupportbasecapable of providing needed expertise for manufacture, servicing and refurbishment of essential hydropower

products for the development of small hydropower systems. It is estimated that for every 1 MW of hydropowerinstalled,twopermanentjobswillbecreatedinthehydropowerindustry8.

4. RegulatoryFrameworkIrrespective of the size of installation, any hydropower development will require authorisation10 in terms of theNationalWaterAct1998,Act36of1998. Theact stipulatesthenecessityto registeraWaterUseLicense,andthe

followingentitiesarerequiredtoregister:

• Individuals–suchasfarmers,small‐holders,land‐ownersorlessees.• Communities–suchascommunalenterprises,traditionalfarmersgroups.

• NationalorProvincialGovernment.• Companiesandbusinesses–includingpartnerships,publiccompanies,privatecompanies,companiesnot

forgain,guaranteecompanies,foreigncompanies,incorporatedprivatecompanies,closedcorporations

etc.• WaterUserAssociations.• WaterServicesProviders,includingWaterBoardsandLocalGovernment.

9BaselineStudy:Hydropower inSouthAfrica,Department ofMineralsandEnergy,CapacityBuilding inEnergyEfficiencyandRenewableEnergy(CaBEERE)‐2002

10DepartmentofEnergyWebsite‐http://www.energy.gov.za/files/renewables_frame.html

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Registrationdoesnotsetupentitlementtousethewater, thewateruse licenseauthorisesproponenttousewater.

Registration should be seen as the first step in establishing a relationship as a water userwith theDepartment.FormstoregisterareobtainablefromanyofficeoftheDepartment.Registrationcannotbeturneddownordenied,ifthewateruseisofalegitimatemeans.

Thefollowingisabasicoutlineoftheprocessestoobtainawateruselicense11:

• ApplicationsareobtainedandsubmittedtoDWAFregionaloffices.• The regional office will assess the applications and advise on the requirements. The Regional office will

furthermakearecommendationtothedelegatedofficial.• The regional office will thensubmitthe application to the Head Office:Chief Directorate: Water Use for

furtherhandling.

• TheChiefDirectorate:WaterUsewillreviewthelicenseapplicationforcompliancewiththePolicy• TheChiefDirector:WaterUsewillthenmakerecommendationsfortheMinistertomakeadecision.• ApplicantsmayappealthedecisionstotheWaterTribunal.

Formoredetailedinformationreferto“AGuidetotheRegistrationofWaterUseUndertheNationalWaterAct(Act36of1998)”andseetheinstructionsatwww.dwaf.gov.za/Projects/WARMS

5. BarrierstoImplementationThemanychallengesfacingsmallhydropowerexploitationaregenerallysharedbarriersofrenewableenergyindustry

and independentpowerproducers.Thesebarriersarethe lackofclearandconsistentpoliciesonrenewableenergyand associated requisite budgetary allocations to create an enabling environment for mobilising resources and

encouraginginvestment.Furthermore,theabsenceoflow‐cost,long‐termfinancingmodelstoproviderenewablestocustomersataffordablepriceswhileensuringthattheindustryremainssustainableexasperatesdevelopment.

Micro‐hydrofacesthefollowingspecificissues12:

• Limitedaccesstoappropriatetechnologies,withspecialtechnicalchallengesduetothelocalcontextofsmallheadsandhighvolumesorveryhighheadsandlowvolumes.

• Limitedinfrastructureinthefield’sofmanufacturing,installationandoperation.Eventhemostrudimentary

turbinesorpartsthatare criticaltomaintenancehave limitedmanufacturing supportonthecontinent.Anexample is the un‐available capacity to manufacture high‐density polyvinyl pipes that can serve as goodpenstocks ‐ few countries have these products and as a result implementation at simple sites has been

hampered. (However,duetothepresenceofthemining industry inSouthAfrica,there isa large industrialsupport base in existence, capable of providing the needed expertise for manufacture, servicing andrefurbishmentofessentialhydropowerproducts,whichisprimarilymining‐typeequipment.)13

• Limitedcapacitytodesignanddevelopmicro‐hydroforareassometimesconsideredtooremote.Generally,SouthAfricahaslimitedcapacityofexpertstoundertakemicro‐hydrofeasibilitystudies.

• TheregulatoryadministrationissuesrequiredfortheWaterUseLicense.(TheDepartmentofWaterAffairsis

saidtohaveastrategytoguidetheprojectdevelopmentofhydropower).

Themicro‐hydroexperienceinthePhilippinesisthatoff‐gridelectrificationishinderedbyhighupfrontcostsandtheneedforgovernmentinterventionandsubsidy14.

11GuidelinefortheDevelopmentofRenewableEnergyProjects,2008–EthekwiniMunicipalityKnowledgeRepository

12SmallhydropowerforruralelectrificationinSouthAfrica‐usingexperiencesfromotherAfricancountries,Klunne‐CSIR2009

13BaselineStudy:HydropowerinSouthAfrica,DepartmentofMineralsandEnergy,CapacityBuildinginEnergyEfficiencyandRenewableEnergy(CaBEERE)‐2002

14DepartmentofEnergy,Philippines‐www.doe.gov.ph/ER/Hydropower.htm

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GovernmenthaveestablishedtheWorkingforEnergyprogrammewhichwelcomesprojectdevelopers interested in

providingsustainableenergysolutionstoruralcommunities,usingspecificallymicro‐hydro15.

15Moreinformationatwww.reee.sacities.net/resources/wfe.htm