J. H. BechererIENDRS4-069

INDUSTRY AND ENERGY DEPARTMENT WORKING PAPtMENERGY SERIES PAPER No. 47

Kerosene Stoves: Their Performance,Use, and Constraints

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Report No.:11345 Type: (MIS)October 1991 Title: KEROSENE STOVES: THEIR PERFORMOctober 1991 ~~Author:

Ext.: 0 Room: Dept.OCTOBER 1991

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Joint UNDP/World BankEnergy Sector Management Assistance Program

(ESMAP)

KEROSENE STOVES:

their performance, use and constraints

by

Willem FloorRobert van der Plas

Octobe 1991

1n ndEntf D.p,mnEnV QmddB MW7Th wowW SW*1818 H S N.W.

ab,g8, D.C. 20433

This mpt tea of a sew lesu*d by Mhe ixfuy adEney Ds.pw"N for dh kutoWan and gWdmao Bo* W"f. ft ma not be puM.ed or qwosd asrursehn ,ftw of the U nk Bw* p, nor don the Bw*Gaup aowept ,.poVt hr to JOIDUor

E XBECKROU ND .. .................... ................................. I

IntrodK uton .. ... ................ .......................... IInter-fud SubstitLuion . . ... .. .......... ............ ...... I

2X DNMlODUC1lON ............... ...*........ 8Wood Snto ................................. 8Charcoa stoaes ...... ......... .. .. .................. .... SLPG Stvs.......................... .. 9Ned for a Krose Stave for Aficn H ouuShhI . .... .... ....... .. ..... 9Deveoqpment Work on Kao ene Stovs ............................. . 11

HWigh power w ss . ................................. . 12Lowtpowweick stow..es.. 1 .2 .. ... ....................... 2Pre modlo d 8 0 0l..aV0o.. ............... . . .. . 12

3. HIGH POWVER KEROENESTVE ........................ 15Waaw BoCong pab . ......iffereat . . rO.. ki.. . ................ 16

et te .x..dsb . 16

Aiuain h1(Stove odd T) . ..* ................. *...*....................*.. 37

4. LO)W POW)ER KROERXNE SnYVES ................... 23

coig ta ................ ...... 24C9suuqerAUXETabtDTd *.-........................-.............-----*e.... 26

Thee" oddel oef Itme and FOuelSavip ................ 26Skm I *04iatiom ,..,,....................... .. ,,.......,,. 27Flow resuictbn .................... ....... 28

S. CO)NCWUSIONS ............. ......... *0.....30

Anna I: F'nuus Cbn4micn of DSet Aeb"lvs for S^sCooing ......... 32

Anne E Testiqgof P esuied St^em ............. t . . 36Pb"w Rating Too .......... ......... 37

Aw m (Sk Mad) .o......o.......39

TaM I v-G o hRae(8 ................................... 2

'table 1 Average Groth Rate ( 8 4 - 87) ............ ..... 2Table 2 Comparisn of Household Fbuels ...................... . 4Table 3 Skwe Use in Niamey, Zinder, and Maradi .............. 8Table 4 Fuel Conaunption Parneters .......... ......... 10TableS Specifi Fuel Consumption for Different Stove lTpes ........... 18Table 6 Controfled Cookig Tests with Kerosene Wick Stoves .. ......... 25Table 7 rine and Fuel Saving Options . ..................... 27Table Al.1 1990 Fuel Pres in West Afkican Countries . ........ 32Tale A1.2 Fuel Cbharatrisics....... ........... 32Table A13 Stove Charatistics . . ...... 32Table A1 Annual Costa for Cooking ....... 33Table A2.1 Summary aucrist of Preswrized Stoves . ....... 36TableA2.2 Power Output Nozle DiamewerCobinatio . .. .... ... 37TIable A2.3 Characterii of a 4 kW Pressurized Burner ...... .. ........ 38

Figure 1 Keosene andLPGC imption(70 . . ........... ....... IFgue 2 Kromsene and LPG Cdonsunpton ......... .. 3Fiure3 Rightand Wrong P stion ofEvapotor trSha i........................17Fiue 4 Relaion Betwen Power Outputt and Efficiency of the Stove ............. 24Figure 5 SFC as Function of Stove Power ..... .. ................ 25Fre 6 Coolng n a Function of Stove Pow . .................. .. .. ... . 26Fure 7 Reldation Beween the Effiiency of the Stov and the Ratio of Pan nd Buner

Dianeter ........................ 26Figue 8 Breakdown ofTotaAnnua Cooking Costs (All Countries) ........... 34Figre9 BreakdownofTotlAnnua lCookdigCosts(M aurtaaia) ............. 35Fipre10 BreakdownofTotalAnnual CookingCosts(N*wr) ............. 35Figre11 ThomnasCup ............... 39Figue 12 PEl... .... * .... .. ....... 40Figue13 Prinus .. . .... ................. 41Figme 14 Supero r. .**.............. # * O.. ***** 41Figure 15 Zeppeln............. . . .... . ... . *..* ............... 42Figurl6 N I...e .** ............ * 43Figure 17 Bip Bandkh ......... ...... . .................. ..43Fiure 18 Malgahe Chuaoa= .......... ............................. 44Fige 19 Sakkanal .......... .... . ........... . .... . .. 44F*mue20 Rnederea ....... .................................... . 45Fgure21 R tj. Jiko . ............................. 45FirWe22 Wa.g.he Wood . ........................ 46Ft= 23 Ma Sauki ........................... ............. 9 ..... 46

ACRONYMS, ABBREVIATIONS, MEASURES

Co Curbon MonoxddeEDP E Vergy Department PaperT Index of Toxcity

LPG Lquirled Petroleum GasSFC Specific Food Cnsumtion

1 MY meg Joule - 104GJ- 103 kJ' #OE tons of oil equivalent - 42.5 GJ - 10j2 million keal - 40.5 mfllion BTUI MT metric ton 1000 kg1 kg of wood 18 MJ (at 15% mcw", moisture conwent wet base)1 kg of charcoal 31 MI

lter okerosene(= 0.8 kg)35 MI1kg of LPG 45 MJ

EXECUTVE SUMMARY

In this report we dsow that, althugh LPG and other fels are ining ground, kerosene is tim amajor household cooking fuel in many countries. A partcular case is Indonesia where in 198 some135 PI 1 (3.8 million me valued at US$400 miion) of keose was usd In simple kerosene sovesFew othr eanergy technologies use such re quantities of fueL Impvig enerna efficien inkerosene stove, theref, coud yield potential large fuel savings and coud be an eonomiallyattractive actvity. Te purpose of this report therefor is to show how it is possible to inae thepotential for kerosene savings, imroe household welfar and reduce the cost of supynkeosene to the economy.

Prior to the field actii on which the finding of this report are based, research on kerosoestoves haJ identified the key de ans of stove It also howed that theperformance of eing stoves varied greatly. Based on thes findings it was docided to:

(a) identify and test a high-power stoe adapted to West Afrcan conditions an,if necessy, modify its design;

(b) test the laboratory resuts in the field and work with users ad produes ofkerose stoves; and

(c) raie the qualty of existig low power kerosene stoves athr than to developor identify a boest stove.

The acvities undertaken consited of stove testing and coa_ner acoeptabiity survy supportedby appied research. The field suvys were preceded by water boiliog tests to provide technicalpaamnete such as the eq and power of the stoes to be field tested. Because theselaboratory resuts do not show how much fuel is actuallY used for a certain cooking task, controlledcocking tests wee conducted using a standard meal prepared on differen stoves lese cookingtests drated the potential fe savings reuting from the use of a more efficit model, butalso those resuling from a chang in consumer bebavior. In addition, safety tests were canductedto determine the tempeature of the relevant parts of the kerosene stovs and to meas thequat of Finally, conmers were given the modified sto for use at home and totest them under real life codi The debriefing of the houseives yielded much practInomadin about the pros and cam of the use of a partar kerosene stove. Thee conum_remb led to frther alied rech to try ad address the problems thy had identified. As aresult of these actvie the folowing condusion can be drawn.-

As far as stoes with a power output higher tha 3 kW are concerd, we have been able to ideiafanddopt an Indonesian wick-sove, the Thomas Cup 36 (P . 5K)K, for use In W. Arica

households. The 1, was d to be an adequae and muatable keoe stove durin

1 Pi N . O GI - l,amo u

Kamm"sa StowsPp

merous field tests in the Cape Verde, Senegpi Maurita, Burkina Fa, Mall, and Niger.Hsees have indicated that they consider this stove to be a proat -t that they like and arewiling to buy. Ihe tve is efficient and reliable, and therefore acceptable to o Mer Currently,dte TC31 is beiag marketed in Niger as a commcial product

Anothier potentily promising kerosene stove (of the pressrized type) Is the Columbian Superior(P,, -5 Kw). However, despite its ve Wpealing desi there are sti tehl problems withthis stove, which has been designed for use with codnol (an itermdiate product between keroseneand psoline) which is not avaiable hi all countries. Some of these poblems have been resolvedduring field tests, others however stm remain. Further, applied research is necessa, in partiuato addrs the issue of kerosee tance.

Additnal work on stoves with a lower power output than 3 kW n Indoneia showed that thetechnical changes required to save kerosen and/or change the power of most existing kerosenestoves are siWle and ineensve. For examle, simply turning around the pan support (at zerocost), and plcing a flow rescor at the bottom of the flame holder ineas the stove's eiency.Further reearch may yield additional simple and in ive, energy saving technical canges.

The economics of kerosene cooking in Indonesia suggests that a 5% change in a stove's keroseneconsumption would be worth over Rp 500 (present value) 1 to a typical consmer, assumig adisnt rate of 10%. The additional cost of producing such a change would be much ss Foreaml, the cost of an arfiow-restictor (<30) Rp), omitted in most art l sov could lead toan avea kerosene savings of 3-6%.

The workin Indonea also showed that, consumers purchang a stove cauuot asceta its fuel.eoomy, either through physical ection or reputation Als, stove produe are alo ignorantof ti stve' fud economy. Civen the diversity in quality of output, for the same model bythe same producer, implies what is needed is not so much a bettr stove desi, but rather a changein the qualit of production and to create consmer awaess about these issues

In both the W. Afican and Indonesian cases it wu d that simple behavioral anescan sav cobddwable amounts of kerosene. Turning down the power during the simmering proe(which is not done by many househdb) can save up to 10% of kerosene used. Also, the effectof the technial and behavioral chas are interdependent. If a 10% more efficient stoe is usedat the same high powe stting (for a typical Indonesan meal) as with the nonficnt stove, 3%of dw kerosene wM be saved Tis higbr efficient stov will thus deiver more enr to the pan,which, could result in time savins. I in addition, the power output is reduced by 10%, so that theket delivered to the pan remains as it was with the non-efficin sov ths wil sm 6% of the

Furh applied research progmms to improv keros stoves can be exe to uinwraddioal keose savihng p b The two simae technical chang identified for low powe

3 IJS 1 - RP 10 (1990)

Krene es tag.e Hi

stoves were uncovered in a relatively short time. It is likely that frther savings could be obtr tnedfrom other design changes by, for example, changing the quality of the wicks used, andimprovements in the flame adjustment mechanbm.

Finaly, this report confirms the Bank's earlier finding that wick stoves appear to be a generallybetter technical option than most prese stoves. Good wk stoves have efficiencies of 40% ormore as compared to 55% efficiency for - - ,urized stoves, but are cheaper, and have feweroperational problems. The Columbian Super - stove could be an exception to the rule, if certaintechnical fuel problems can be resolved.

Kn'su Siff PI

1 BACKGROUND

1.1 The household energy sector is the lat of all eneg consming subsectors in mostdeveloping countries Households account for 40%-$O% of total enery use, mainly depending onthe level of dvelopment of a particular country. Ihe household enerV, sector often is also thefastest growing one with regards to consumption of modern fuels such as kerosene, LPC, andelcricity. lhis growth is manifested by a sometimes rapid switch from traditional to modern fuelsin the urban areas

12 Tradional fuels such as wood and charcoal provide the least cost solution to householdsin many low-income LDCs. However, this is so only because wood fuels are normally not pricedat their economic costs: the price strure of both wood and charcoal normally includes a largecomponent for transport and wholesale/retaI, but very litde is accounted for the costs to grow thewood or replae it; costs related to environmental damages resulting from overcutting of wood areusually not incorporated. In addition, woodfuels can be purchased in quantities which suit consumerneeds most close1y (in small monetary quantities), while cooking equipment costs are zero or vetylow. Households therefore continue to use woodfuels uns: (i) scarcitie start occuringfequentlyr, (ii) woodfuel retail prices increase substantially relative to modern fuels; (iii) disposableinomes increase; or (iv) subsidies are provided on modern fuels and equipment

13 Wood and charcoal stoves are generallyinense - if not free of costs (e.g three ere a CTstone open fire) - and uses discard and buy new stoves when needed, which in the case of 140

charcoav stoa may be two times a year.Because of the low purchase price, the decisionto by a new stove is normaly not an issue for S0

dcussi with the head of tie household, 20 =

unless a switch to anothe fuel is proposed. 0 72 74 76 79 00 S2 94 St S0

Int-fer- Subhstitu_tion

1. The use of moden fuels (kerosene, '10: w^ gbbn

Uri, eleti) is on the rise within the urbanareas in many countries, e i amongouselholds in the middle and hger income

brt8 3. lbi ener switch is due to a combinaton of incomes, increased avaiabty and/ac t of£moder fuel rap uaseW pric an declining supp of bims

elsk in combinim with lw (often d ) modern fuel prioes It is likely that this inter-fuelsubstiution wM continue in man of the developing coutries in view of rising n he

SW Nun 1 wSM &P fti u ke . ead LPG maptdo ft mU dwdopWiI cosano co_mbie, ad fo- m ICURb

Km.., Sttes Pap 2

often existing price differentials are in favor of this substitution in many countries and areaccentuated by the higher end-use efficiencies and conmfort levels of modern fuels.

1.5 Table 1 shows average annual ('84 - '87) growth percentages of petroleum and LPG use InAfiica, Latia America, and Asia. Kerosene use increases seven times faster than LPG in Africa,while LPG use increases 2.5 tines faster than kerosene in Asia. In Latin America, keosene useactually dedlined, indicatig that these countries are one step further ahead on the road tosubstitution to LPG or electicity from kerosene than their counterparts in Africa and Asia.

1.6 Of the modem cooking fuels used by.households in developing countries, karosene fau*1I f'k .dominates (see Figure 1). Although its .E*'i.

growth in consmaption is, generally, not as.~.pronounced as that of other modern fuels, one should realize that a decline in the giowth .i of kermsene consumption generally occurreo 1*4 .

while there was a siutnosincrease in the use of other, 'more convenient', fuels such asLPG, natural gas and electricity ~. However, Ta i1'at the same time, such a 'decline' masksongping penetrtion of kerosene in other segments of the household sector that were usingwoodfuels Previously Kerosene invariably is a households first modern fuel when it dlimbs theenaV~ ladder while LPG in many cases is the second modem fuel which is used only after thehousehold used kerosene for quite some time. First, kerosee is used as a lighting fuel (in urbanas well93 in runalareas) and to ignie the wood or charcoal for cooking. and finally it is usedas aprincipal cooking fuel.

1.7 in Asia kerosene dominates as the urba household cooking fueL Ini Indonesia kerosenaecmout for over one quarter of petroleum product sales, with about 7 mOoio mi3 sold in 1967.Of this, about 3 mlfion m3, or 40% of to-ad sales, were sold to 93% of urban househods'.- Othemajor kerosene user in Asia are India, (35% of all urban households), Pakistan (42% of urban

houshols),and Sri L anka (30% of urban households)'.

1.8 In some countries of the Middle East, LPG is making inroads on the posfitio previou*lheld by kerosene., but the latte stll is an important household fuel in countries such as Egpy,Jordan, Turkey, and Tunisia. in Jordan, for example kerosene represents 34% of total final energ

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AFRICA

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KEROSENE 22 LpG

ASIA (llnl. Middle Eust) S. AMERICA

million MT millon MT

0KERSENE 0 LPG K aS LPG

* 2:. Kerese and Us cowmpf

Muse by houeods in 198. As suc:h it stf outpaced LPG which taki second with 29%7In Egypt, kaeose 'Was used by 13 mMiLon households in 1981 ', while in Tunisia, 27% ofhFsdk used kaeosene in 1984 9,

W9 In Ain America thie use of kerosene for household cookig is by now leso wdexd tbaitwas a decade ago and LPG is caffently a more irapotnt cooking fue than kmero Howw,,ther are quite a few countries where keroee use is important, such as in Peru while abo in mmC:eltn America countries keroe stil occupies a maljor pstion l°.

7 GOPA.h& EO Pbf AyAO M Dead in the HWM Sa, Jj M.

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aidus byhueod n18.A uc tsilo:ae P hihrn~ eodwt 9InEytkrsn asue y1 ilo hou_sehlsin18 m hlei unsa 2%o

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1.10 b Aica kmerosene is used redd We byhu ks fcokSpuoses Insm

70% of the howod usekasew as a oooWqg Pue u. In Dzjibu neady 100% of tXbouJ in d pial city u krsene as cooking t, wi in otbr town the nube of

K _ So s fS

househokd usng kerosene vary between 44% and 76% '. Simlarly, there is some penetrationof kerosene as a household fuel in Nieri (18% In 1981 , Zair, and Coqgo. In other urbanareas in Africa (Naibi, Dar es-Salam) a larger number than the curt one (25%) of householdswoud use kerosene as a cooking hel, if it were accesble and repul availe . That theswitch from bioma fuels to kerosene can happen very rapiy is demonsated by the case ofEthiopia where wiin a three year perid (198447) the households in Ads Ababa changed fiomhaving no keroene stoves to 70% of the housholds having one. As a resut of this switch it isexpected dat kerosene wil be the mowt important houseold fuel in urban Etiopia in the 1990s1'. Of course, the situation in Ethiopia is not typical for other Africn countries. The switch tokerosene as a household fuel was occasioned by the act that there was an increasing scarcity ofadiiona household fuels concomitant with risig and widly fuctuatin pie and a switch to lowqualty fueb such as agiculural wastes, twis and leaves. Expenditr for houehold fuels increasedto one-third of cash income for poor households In view of this situation conumers adopted astrateg of diversification of fuels for secuity reasons. Ihe suoos of the keosene stoves can beascrbed to the continued acce lity of that fuel on the market, the availabiy of adequateappliances, and stailty of prces for both the fuel and the stove

1.11 A different inter-fuel switch was also observed in the case of Cape Verde where until 1984,some 60% of urban households used kerosene as their prnipal household fueL In 1988 thispernta has dropped to 12% due to a major switch to LPG 16 ThIs shows that - on thehousehold level- kerosene and LPG are inang , and that the main determining factor areincome leve,1 availbiliy, and convenience in use.

1.12 Why this attention for kerosene, given the fact that more comfortable and deanor cookingfuels are available, which also have higher end-use efficiencies In fact, severa Aircan emake a conscous effort to introduce LPO rather than kerosene, as a preferred urban cooking fueL,even though it is not the most economic solution 17 The reason for focussing on kersene stovesi hat kerosene offers in many cases the least-cost solution for houseold cooking in many countristhat stat on the road to stitution. It provides the user with a more moden, dean, and efficientcooking fuel compared to charcoal or wood while at the same time, conideable ener' savings and

ESMA?, Kg=&JIm.oLQ_int iuJ iZn3 198

14 ELU: Tmf - U,lan WooRdful SiumSsl4v &Vlt L

Is UP. Mink- UAn t 9.Hr,XaESMAP. Ea=ln usog= t 1, I98. Howeve, this outletaigIssmay no oqr MM at pl ' boewm ti euDit, Iw-aa kIoms Ms fom t Sodt UnWaam so low WdMio

X mAP. X g Yak xatmu.adr 1M

1? M1 CHL ousutdI (Cgsm Vetde, CM4 Emuki Fuo V(Al Maidmba, NAW, SmW uopi,)v4flaadl sfm htm dk fomtimpu~ma CommoAky htoai fwr mampi to make .bdudh LPG bota) waIdIto do _ hmmemr in uuIaftLG deqitedo fe d) do LPG opto is adm dout-oui codit d

f hfr dwo m0tls

Kreisue Stowe ?q4 6

biOmass fuel saving are obtained After all keosee is extensive used as a maor oooking fuein very populous Asin and Latin American countries, where other modern fues are readilyavailable, and there is no reason to doubt that this cannot be the case for many African countriesalso.

1.13 In Afica, problemswith kerosene as an urban cookingfuel are likely to be end-usc orientedand not related to -, t-ansport and distribution. Attention should therefore be focussed on thestove. Transport -t i stAribution of petroleum products a well esablished prctioe and appearsto be relatively : ". kerosene is used for lighting even in the remotest areas '. Storage ofkerosene is quite &:ukLe and modem faclities eist parallel to casual facilities like barrels, re-usedbeer bottles, etc. It thus appears that if the demand for kerosene increases, the existing splnetwork wi be able to meet this demand.

1.14 What do we know about kerosene M. stoves? The curet wick stove technology only ~..'dates from 1916. Research on kerosene li.i wia#IIhousehold devices bascaly came to a standstl .W § 3m s k s.after World War i, after wM-ch households in -- ~j j

westen countries inrasingly switched to .coalgas, LPG, naural gas and electt. Ihe . .state of the art of simple kerosene devices l .m.which was depicted in 1937 by a student of the..use of oil products (see text box I 19), isgenr*still valid oday. _ @ _ _

1.15 In view of the fact that more than 1/8 t box 1of the world population use kerosene forcooking and/or lighting and that no reliable and modern information on keroene stoves wasavailable, ESMAP in 1983 asked the Woodbuing Stove Group of the Eindhoven Univet ofTechnology, which had done much work to put biomass stoves on tLe scientific map, to test anumber of commonly used kerosene stoves to obtain a better udetanding of their performanceand ha i The results of this work were published in September 1985 °. Thi report,based on an exensive testing proga of 18 kerosene stoves, revealed that most kerosene stovesin use have a rather low maximum power. This, in combination with the meased efficiencies,would reult in unduly long cooking times when used for food prepation in, for example, manyW. Afican counties

U s is s ol_w,ado. nodhig is "W abost atau prictinv4 tana & retur an, OM.

W Raop, OU Mds NybM THelopse, 37.

D Bsy Dqatmet Pawer N6. 27. Rel,osth cited as EI,P No. 27.

Ku.....~~~~ ~~~ Stv Fag 7

1.16 In Chapter. I the omparative advautages of modem fuel oves are correlated to biomastoves. In addhion, devopmetwork on keosen stoves are hghlted Finally, the stoves thatwere tested are disussed in some detail.

1.17 In Chapter M the reult of the lboratoty work and fiedd tes with high power stove aredised and cnsions are drawn with regard to safety and e Mental apec as wel as toconsumer acoceptablit of these stoves.

L18 In Chapter IV the low power stoves are disssed. It is shown that there are qualt andsafety probaems with these stoves. Also, that ineesve technwa improvemts can be easyappled in eo ft stoves. Further, the importanceof consumer behavior is bhilighted.

1.19 In Chapter V poicy and techncl conusions are drwn for operatonal use.

Kene scames Par 8

2. INTRODUCIION

21 In the earlier EDP 27 rport ESMAP conduded toat most kerosene stoves, althoughrelative1y efficent, have a low power output. For certain countries - certainly in the Sahel - thisis one of the main obstacles to their acceptance. lTe same rpt fiurther concluded that stoveperformance could be enhanced by desig and operional ivemen. In view of thesecondusions, as wel as the importance of kerosene as a subitute household tuel, ESMAP continuedits actMies in the field of kerosene stoves with a view to:

(a) develop a kerosene stove suitable for W. African cooking practioes; and

(b) attempt to further improve kerosene stoveperformace for Asian countries.

The followng sections will report on this folow-up ESMAP work and on the results that wereobtained, but flrs the state of the art of wood and charc stoves will briefly be discussed as thisis the actual situaton before households switch to modern fuels. See Annex II for drawing of mostof these stoves.

,Wood Staves

2.2 Wood stoves commonly used mn Africa are .

the three oe open fire, clay or ceramic soves, ormet stoves In urban area when householis usewood, mainly metal stoves are used while in rural _____________

are moy three stone stoves are used. Table 3 ishows the distiutiofn of stove use among 180 wood using households in 3 towns in Niger (1988). i i _Typical retai prices of these stoves range from F.CFA0forthe3stone stve to FCFA7SO- 750 -1000 for the Malache and F.CFA 1000 - 2000 for X m. _the imoved stoe 2 Te median daily wood | . * ,

pchase is me F.CFA 150 per 1 :houseold with a taditonal stove ergy savingsrage from 20% to 30% cmpared to the trdional metl (Malae) stove, and more nampared to the 3 stone stove.

23 Charoal is not oommonly utlied in all countries, but there where it is used, the metalMa4ache is the most common stove Improved chrcoal stov exist in many couties, and the

2 w F.CFA 298 /W (19)

AMmag Rh uudidau gore for both cmosI sd wood we aenm uf.aod to at Mopdm .ve, dtheanwh* q.E .. charnel *Oe hwadw empi a at. an VWh0th fe i bune.

Kt"WM slova Pa 9

model(s) used vatry m ountry to country. Te Sakkanal stove is ted in Senegal andMauritania, or its variant Muli-V3; charcoal use in Burkina F and Niger is Isgairicant andimproved c l stoves have not been introduced there; in Eastem Africa, there are the KeogoJko in Kenya, the Rondes in Rwanda, etc. 2s. Imprved stoves are typicall 2 t. 3 times moreexpensive than the Malgce stove '. Average daily charcoa expendtures ange from F.CFA 200- 230 per househo_d in Senegal, UM 100 - 130 in Mgauriania, F.CFA 225 - 250 in MalL, and FRw65 - 80 in Rwanda.

L,G Stove

2.4 Several LPG stoves are found in W. Africa and thy may appear under different names indifferent countries. 'Me most fiequently used modl i Senegal, Mali, Niger, Cape Verde, andMauriania are: Blip Banekh, with a 3 kg botde (Camping Gaz, UM 2200); the Nopal dwith a 6 kgbottle (Total, UM 3000); and a Carena with either a 3 or 6 kg bottle (Camping Gaw, UM 2800,botde exta). In Niger, apart from the Camping Gaz models, the Dor6 can be found, having aconicaL mutmannite pan support adapted to local ooking practices, using the 6 kg Total psbotto and a Primus burer.

Need for a Kerosene Stove for Afdican Households

2.5 Severa African countries have woodfuel resources which are In a precarious condion.Options to aleviate this pressure are being pursued, hiuig d ion of impoved woodfuelstoves, plantin of trees, foret mt, and substitb Jon of cooking fuels. When anideredor a per meal bas, one can condude that in general cooking with woodfueb is not the best apto:desp improved sto (which can reduce the cost of cooking up to 30%), cooking with kerosnerequies the same or less moey, and is more comfortable. Tbis depends of course on the relatpricig levds of the differet fue, but in gneral it is valid - at least for many of the Sahelincountrie Although improved wood fuel ses can ave up to 30% of te energy used, keroneand gs stoves could ae up to 65% of the energ used for cooking In tems of wood however,kersene stoves save much more than the best wood fuel seer wil save. With that in mind,field test (as pat of Household Energy Strateg development work) were done to identifyhoueholW opinon on these issues i several countris

2.6 Table 4 shows, as an eamp the verage spedfic fuel cosuption t for the preaatipof tre sadad meals in Burkina Faso (white rice with saue, fid rice with sauce, t sauce;a tota of 16 kgrice/t and 8 lkg saue for each stove) It s de----- that the SFC for LPGi the bwt, flowed by kerosene, and wood. ITis test did not include chrcod becas it is not

1 For todm detm *o }SMAP: Too Raub e Cll Stovs fo Devuopsg Countries Doc. 1RWAND Eaism w.ih do lI ved Choud Stoves 19 (in pit).

) Ms_m co PCFA 4S-6S0 - 1967)1i Sh &; UK 1M9- 600 in Mah ta (1; F.CFA 1000 -Sin N.M (1965) ad FEw LI) in Rwamnd

UVidbw i( lStalalaiuo Rmusdoseokffod

KamuMO Stows Ppim o

used for cooking in BurkinaFaso, but would it have 1 p-ibeen used, the specific fjtti.tflnconmsunpon would pro- wo

abyhave been on the ......

same level as the wood $7.stoves.4*~~q*~t*VS~ W . .

2.7 The analysis can be e.taken one step ufurter, and by calculating the substi:..::

one, kg of new fuel ([PM,. . ~. .

kerosne, chrca) would W& 4-replace an amount of x kgof wood in the traditional 3 stone open fire. In this partiar case, the improved 3 stone open firewould replace 1.5 kg of wood used in the traditional 3 stone open fire; simIarly, 1.6 kg of woodwould be replaced with metal woodstoves, and 4.9 and 4.8 kgrectively with kerosene and LPGsoes. Thus, the substiton ratio would be the lrgest for kerosene.

2.8 Field test within the context of the Niger household energy strategy project (1986)demonsat tht for use in a West African country, a wick kerosene stove which has a high poweroutput might offer a suitae alernative for household cooking purposes. One of the kerosenestove models with a moderate to high power output and a hig popuarity in Indonesia, the ThomasCup, was tested by households in Niamey and Zinder (Niger). The results of these test showedthat initil perception of the households was quite positive However, it was found thatiovements were necessaiy on the mechanical and technical aspects of this stove modd, inpartiular its maximum power was too low in comparsn to wood and gas stoves, reslting in onWercookng tie In additon, the Asian kerosene stoves tested were o sturdy enough for W. Africancooking pcies would result in unacceptably short lifetimes

2.9 Based on households' reactions and the stove tchniian' eprience, aciteria were ientifiedfor such a suitable kerosene stove for cooking in W. Afica:

(a) its maximal power output (P.. under W. African imat condi shouldbe of the order of S kW while the minimal power output ('0 should be le than1.5 kW; the combusion process shoukl, at all power output vs, be such that theemision level of CO and soot are minimal;

(b) its average efficiency should exceed 40%al'

a t pe W' W" -ai the mar ef at am pf e > , P n at a ikul _w4tpt(F5 )

Ksam 8tw a 11

(c) its lfetime should exceed 2 years, even under W. African cooking oonditions;

(d) it should be dean, easy to operate and maintain, and it should be safe, esp. forchildren.

Develament Work on Keroen Staves

2.10 Folowing the aforegoing eoqeience, it was decided to improve/re-design an edstingkerosee stove model to overcome these problems. ITi led to the desig of the PET stove, aprototpe muti-wick stove, which was developed to obtai higher power level and a better tun-dowm ratio than the eristing kerosene stoves. The desig work was caried out by the WoodbumgStove Group WSG] of the Eindhoven University of Technology. The addional research anddesign activities also reslted in a better understanding of the physics of the performanoo of wks2X. Some of the concusions of this work are:

(a) the kerosene transport capacity of the widkis not the llmiting factor in gettg ahigh maximum power,

(b) the maximum and minimum power levels are determined by the size of the free wickend, and the temperature;

(c) the life time of the wicks can be increased by preventing oxygen approaing thediect vinity of the wiciks; and

(d) the temperature and thus the power can be nreased considrably by dosing the pbeween the outer flame holder and shield.

2.11 lib prototype as well as several other models have bee field tested, and the rests ofthese tests are presented in the current report. One observes that two rdativel ditct daseso existin pctice: low-powe stoes (which range in power (P) from approximatey 1 kW to 2.2 kW) andhig-power stoves (with a range of 2.6 kW to over S kW). For the pwpose of this report, a P..of 2.5 kW wM be ued as cut-off point for the determintion of low- and high-power stovesAlhough it is raized that this distinction between low and high power sto is rather arbary,the reason for doing so is the following. The majority of kerosene stove uses, mail in Asia, habva st with a Pmax of 2 kW. For their cooking purpose they do not need a more powerfl stove.Another goup of consumers, maily in Ist America and the Middle East, prefer stoves with aPina of more than 25 kW, often a preurized stove.

2.12 Finay, there is a group of comers which do not as yet use moderm fiels, notably inAfica, which finds the 2 kW power range too low. Consequently, ther interest in these stoves is

2 i_P. P. VUm, B. ebm on tobnuu um at 9o K(lt Ma Woodmagt to Gr7pMbIk*m Unkaivuuy of TednwIog Fdiunry 1L7 (iiauat repot to ESMAJ).

limited, although thes consumers have egpesed an interest in the purchase of ker e stoveswhich have a power rating high tan 3 kW. It is for this reason that we he made the distindobetwee low nd high power scoves, whih is arguably artifiiaL For one coud argue that a goodhig power stove that has a good tamndown ratio can also be used as a low power stove

2.13 Ultimately, only the consumer can and wil decide what stoves de wants Sorne womenprefer low power stoves, because this allows them to work on ohr tass whie cookign Othersprefer high power stoves, because they avow fiasr cookin No single dsoe deswi may satify allusers, who will make their choice based on the trade-off between cost and comfort of the stovesavaile in the market.A few of the stoves mentioned throughout the report are desied in the fowing paragrphs4their design parameters are included in Annez IL

H1g power wick stoe

2.14 The f stove is a prototpe wick o it has a cylndrical burner with 21 wIcks, and avety rigid frame with a conical pan suport. The tank capacity is 3 liters or 2.4 kg whi gives 6hoWs of ful power with a P.. of ael 45 kW to 5 kW.

2.15 T he (TC,6) is an Indonedan stove, which has a cyindrical buner with 36wicks, pbced m a frame that serves as a pan support. The wic ane arranged in two oncentriccirles. These burers can be operated independently frm one another. The tank capaciy is 4 kgand provides 10 hours of operation at full power of S kW. The original deign bas bee adaptedfor the preparation of W. African food such as t6 as well as for the use of spheric pots.Therefore, the suporting stucture has been reiforoed and the pan spport modified A smalervsion also eists the TCa, with 20 wicks, and a maximum power of 3 kW.

Low per wick steo

2.16 It is quite likely that fiy or more different low-pow ve models eai in Asian and LatinAmerin oountries, often losey resembig one anor, either lcally produced or imorted fromCn, Inda, etc, and of a waying quality. It goes beyond the scope of thbis document to desieall (or even generic) brand names, it sfis to indicate that there me enough choices for tecosumer to make a selection. For a desrip of sevea tov, se EIDP No. 27, or otaLEvIAS U.

Pnuwgm -. stoem

2.17 With regards to pressue stoves, EDP no. 27 [p. 43] conuded that these did not seem tohold mu& prospect a a big ompetir to wick sovews deqst their hig d&iec. AltouPressurized stoves perform satsactorly thi operto entb varo This bbis not

only dear fm lbatowy workd but is also confirmed by usr such as in Tfna, for amle, Wo

a R't* and D opmm Cio f,Oisad Gas T _eio, £kM, lA

Karus St8O Pamp 13

complained about the functioning of their currently used presried stoves (Canou) in thefolowing terms

(a) the difculty of lighting and controlling the flame;

(b) the stability of the sove;

(c) the complicated maintenance; and

(d) the quality of the stove.

Lighting a presuized stove is indeed more complicated than lighting a wick stoe, and forinex enced uers dangerous moments may occ when the lhting procedue is not preciselyfollowed.

Pressurized stoves also:

(a) requi alcohol (or another fuel) for preheating of the burner,

(b) are easily blocked by small impurities inq the keroene (which often canot bepented with the prevaling practices to transport, store and handle kerosene); and

(c) seem to offer less propective portunities for local production.

2.18 Despite these negative aspects of prsurizd stoves, to which should be added their oftenher purchase price, many households in quie a few counties use these stoves. ESMAPherefore decded to include these stoves in its field test program, so as to allow the cumer

rather than the tecican dede which stove would be the desired one. Through die work ofWttkowsky2 ' we learnt about the eisence of the Superior, a presse stove manufacturd andwiey used in Colombia, with a power rating of S kW. Based on the aviabeinformation tis stove seemed to meet W. Afican cooking reqirements. Ihe stove therefore wasioduded in the ESMAP testing acties in the Cape Verdes, Mali Tunisa and Niger.

2.19 The most commhigh pre stove is the ,m which its in a variety of models withdiffent dimensons pan suppors, power ranges, etc. he fld resrvoir capacty is typicall 0.5liter, whie P, ranges from 1.5 kW to 2.5 kW. Derived modes eist aIso, like the Z _mli. whichis a Primus type burer to which is added a large keroe resevoir, mounted on a 50 cm highframe; it is used with an extenal bicyde footpump.

220 m S = looks very much lie a as buning tae cooker. The stove consis of a fiuetank with pump, a fiui duct, a gec duct, one or two buners, and a supporting stuctr The

w A. Wikw at L ad Un1_euu__y it Bmwm, 137.

Kaorens p kP 14

Superior with one bumner has a tank capadty of 0.8 litr or 0.6 kg, which givs 1.5 hous ofoperation at ful power, a two-buser model exists as welL

3. HIGH POW EROSENE OV

3.1 The technical perfonnance of a stove is haac d b [aJ the power output (P); b thefuel efiency (E) at different power outputs; and [c3 the ablit to control the power output, whchcan be epessed by the sowcailed turn-down rtio. In addion to technical pefomance parameters,there are severad other aspcts wich need to be tested like safety, ease of use, cleaning andmaintenace requirements. To dtermine these parameters four standardized tests 30 bave beencaried out, vi.

(a) water boiling tests, which seres to esabi P_ E,, P,,, and E.,,

(b) safety tests;

(c) controled cooking tests to detemine the fuel c pin for a standardmeaL and

(d) consumer acceptability tests.

32 Pa, and E.,. determine the speed of cooking; the higher tAese figures, the faster food isheated up. A high E,.. resu in a lower fuel consumption durin& the heating up period, but a highPau ince the fuel -nsumpton; of these two, E., is the most imprtat factor that determinesthe fue consution. However, for the entire cooking prooess, the infuce of P,b and Eb. aremore important becu normally the heating-up phase is shorter than the simmering phase.During the immeing phase, Pu,b is the most impott fctor that detem the fulconsumption. (See EDP No. 27 for more information).

3.3 These tests were carried out withi e context of ESMAPs household enerV stategsmdies in eg. Burkma Faso, Cae Verde, Mal, Nie, Mauritania, Senegal and lnsi The waterboilig tests as carried out in these countries with astance of lal labortore are simlr tothose desied in EDP No. 27. A pan (filed with water to 2/3 of its caaciy) and the stove areweed and the stove is lit. Water is brought to the boil and kept boing for 30 minutes, with thestae at Pmax The stove and pan are weighed at predermined times during this process. Nowthe power is reduced to the lowest level possile, while the water must remain boiling. Thi lowpower phase is continued during 60 minutes, during which the stove and the pan are weiedseveral times. From the data obtained, the power rating P., and P,, can be clated, as weU asthe ef6icien Es and Eaw

3.4 After completing the water bong tests, controled cooking tests and soft tests werecaied out For the contrled cooing tests, the lo countepart pridd a recp ft what isconsdered to be a tpical local meal The cooking was cauied out by local women, under dosesupervision of the stove t ian. Ihe purpose of this test is to arive at an estimtion of the fudconsumpion, that would be achived in pracce, were any of these stoves actually be used by

In saorda v*h tfatnatsa Made rdocrded by MA.

gEmemm Sto. Pa4P id

households In the county. After these series of test, stoves ae finally given to a sample ofhouseholds which give ther feedback on prolonged use of the stoves. Te objective of theconsumer aeptablt tests is to obtain an indication of the s maktsit.

35 Detmination of the power rating of the stoves mendoned above in parWaps 2.11- 2.14and 2.17 was done without a pan. The stoves were lighted, and the wicks adjusted so thatcombustion took place with blue flames Then the stove was operated during 30 minutes, afterwhich the fuel comption was established. ITe minimum power was also measured without a panduring 30 minutes. Initially the wick settings were as used In EDP No. 27 which means that thewick in the minimum positon were level with the top of the wick tubes.

3.6 - The results of these tests show that the behavior of the wick is as described in EDP No.27 and the maximum power Pis in accordance with the number of wicks, viz. 150 W/wick. Theeffiiency is reasonably good at maximum power (45% - 60%). The low power Is in general, noteasy to control because often the lever mechanism does not operatewell, but also because the flameat low power is not always visiNe for the operator. As to this aspect it is clear that stoves with arotat wick control mechanism are easier to control, for the operator tends to manage the fire insuch a way that she can still see the flame. Here the advantage of the double wick of the TC.becomes evdenLt In the experiments with the TCu only the inner flameholder was used to do thesimmering which permitted easy maintenance of the minimum power level of 12 kW or even lower.

3.7 Th Superior has been designed to use odnd (an intermediate product beween kersnd asoline) as a fiel Tests in the laboatoay as wel as in Tunia and dhe Cape Verde

demostrated dthat the Superior performed well with local kerosene, provided the burner was Cdenand the fuel duct was preheated carefly, although the power output was sometimes lower thanmaxmum value In Mali, however, it was impossible to light the Superior with kerosn of Mlianqualt and gaoline was used saisfiatorily. The Superior has been testd only recently, and itsperformance with other fuels than cocinol was not wel known. Wittowsy, In the aboatoty haddetmined its Pmax at 5 Kw, whie in the Cape Verde [Wodd Bank Household Enery StrateWPaper, 1990] it was measued at 3.7 Kw, a difference which can likely be explained by the prevailingwind conditions. In Mal [World Bank, Household Ener Strateg Paper 19911, it would not workwith kerosene, and it was given gasoline instead whh resulted in a P. of l.8 kW an an eeentperformance Measuements performed in Nie (May 1990) onfirmed the resu of airlboatory tests its P is on the order of 4.9 kW, whle its fficen (E. I a- ima 48%.

3.8 Safety tests were performed to detemine whether a stove wa safe to use in househds.Stability and material strength are two of the f1ac involved. However, the most imptort faci the te erau of the several stove parts and of the kers If the stove part, such as thecontrl mecaism beo? ies too hot, the stove cannot be turned down anmre In a convenient way.Keroene has a flash point above which it can ignite (40.i) without fame. the kmer

temperature in the reservoir Increases, the riskof the reXvoir catchng fire inreases also.Kerosene wil start evaporating when itkbecomes sufficiently wartmm, kinit easy to be d

lighted at the filler cap or any other spot wherekerosene vapor can escape.

3.9 Ignition of prsurized stoves is notalwys easy and if done incorrectly, it can b) e h:WW*Uresult in fire hazard. The ignition of theSuperior stove was tested in Nige (May 1990),and it was found that the evaportion shaftshoud be lightly inlined for the kerosene toevaporate corrcty (see figure 3). When the 3 D b ) and (top) p ofshaft is in a declined position, kerosene can not eo¢evaporate and the stove wDI show difficultieswith igniting. Even in the horizontal position these problems may occur. It is therefore necessaiythat the shaft is positoned oorrectly, and consumers be made aware of this.

3.10 These safety tests have always been performed in colaboraidon with a local institution,preferabl one with a standing aiperience on stove testing sch as Onersol in Niger, CERER inSenega, the BIFA (Base Technique Foyers Am6liores) in Ma-,ritania, the SGS Supertestlaboratories in Tuisia, the foresty center (SNF) in Cape Verde, LEMIGAS in Indonesia, etc. Aninternationaly recruited stove techician normally worked in dose cll on with personnel ofthe institution, etablishing testing procedures and trafing personnel in peroming tet andaWg tst data.

3.11 Controlled cooking test do not give much more information than what codd have beendeducted frm the water boiling tests, although diffeenes bw; reen stoves in terms of wookigtimes, fuel consumption are more pronounced. In addition, it is possible to dermine the fel costsper meal for the different stoves. Table 5 shows an overview of the resulb of some of these testsin a _nber of countries.

3.12 The time to prepare a Mauritanian dish, Ceebu Jeen, amounted to between 102 and 104minutes with the TC,,w two LPG stove (Nopal6, 8lip Banekh), and an improved arod stoe(Sakkal Multimame), and 122 minutes with a tad a charoal stoe (Ma4gche square), and

112 minutes with a presuized kerosene stove (Zeppelin) and an LPG stove(Carena). Te differenes between the LPG stoves and the kerosene stove wen most dear intem of er use: the keoene stoveused on average 2.0 MI/kg of food cooked, whle the LPGstoves used 1.6 MJ; the charcoal stoves used 2.0 Ml (improved stoes) ad 2.3 MI (tradiol)

respectivly. Hower, in . . after of fuel costs 3, the ~ ~ kerosene stoves used 9.3 ~ V UM per meal ($0.12), while " 5the LPG stoves used 14.0 ~~ ~ ~ , 1UM ($0.19), and the char- t 2 ; 1 S 1 coal stove 12.5 UIM (un- ~* * ~ ~ ~ *A4proved) and 16 UM (tadi- . _ __. __. . _

tional)o. 136M"o h

3.13 In Cape Verde,diffaert stoves were used f f S .

in the antrolled cooking . e. 6 ff e s lttew and the specific fuelconsumption (SFC, per kg m,ie.of cooked food) was the Tabl e wWefollowing: 13.6 MI for the3 stone open fire 7.6 MJfor an improved wood stove, an average of 6.2 Ml for the LPG stoves (Ensaol Small, Camping GazFeu, Camping On Carena), and on avge 6.4 MI for the kerosene stoves (Lux-1, TCov Pets,Sunfower, Zepeln). In terms of monetary saving, none of the LPG stoves could be cheaper touse than wood toves, and some of the kerosene stoves could only be margll cpap to se thanwood stoves.

3.14 mh SFC in Cape Verde demonstates that it depends on the tp of meal prepared: inCape Verde, a long simmering period is requirdJ, which, in combination with prevailig windconditirns, result in an SFC which is substantially h4fher than in othe countries.

3.15 In Senegal, Ceebu Jewn was prepared on wood, charcoal, LPG and kerosene stoves ThSFC for the diffent stoves in this case was 3 stone open fire 3.7 MI per kg of food prepared;Sakkanal wood stove: 3.1 MI, averag for charcoal stoves 2.1 MY; averag for kerosee stoves: 2.4Ml,- averag for LPG stoves 1.9 MI.

3.16 In Indonesia, Chap Choi (chicken) was prepared on kerosene and LPG stoves The SFCwas sdown to be a lnea functio of the stove's P... with an averaep valu for ag. kerosene stovestested of 4.4 MI, and 3.3 MI for LPG stoves.

3.17 The following four condusions regarding the speci fad fueleran,ethough different tye of meals were prepared:

(a) the WC for stove using woodftels is geerll higher than for thos using modem

"1 Both fiw ane ni subiifau

Kweuss ows miap3

(b) the diffece in SFC betwee mprved stove and tadhita stove is qutedificant (both for charcoal and wood);

(c) the SFC for wood stovw is higher than for charo0d stoves; and

(d) the SFC for kerosene stovesis approximael b 20%W hier than for LPG stoves.

Two remar need to be made, rearding (c): if caclting the SFC in tem of primay ener, theSFC figu for carcoal stoves needs to be mtpied ba r ately 5; thi means that the SFCfor carcoal stoves is much iger than that for wood stoves, reecting the infficiny of charcoalproduction; and regrding (d): the SFC diffeence between LPG and kerosene stoves is inaccodncewith tetheoreticald exctation: LPG stoves are aprimately20% more efficient thankerosne stvs, and the difference of the calorific value of both fue is almost lie same.

Q M _Acoetait Tet

.18 Ihe stoves were also submitted to a consumer acooeptab survey In a number of W.Africat countries such as Cape Verde, Mauritania, Mali, Budkina Fan md Nigr. The standardmehod was to invite a number of households to cook their meals with the soe during one weewkPrior to this, it was adapted to the shape of the spherical cooling pots, while the upport semwas reinforced to allow the preparation of local foods such as t6, that requi heavy stirrin& Also,the women we shown how to use the stoves safely and efficiently. In addition, the maintenancerequiments were epained, and each par ng household received a quantity of kerosenesufficient for 2 to 3 days. DurnS the test period, the households were viited by a surveyor and atechnician each day. Obsevato were noted and technical problems, if any, were solvaed. Afterthe test week the women were debriefed as to their reaction and the diffenes in peeption, IaxW were noted with those prior to the test weekL

3.19 In Budkina Faso the particpting hoseholds unanimus acepted the 'W, stove, and thefolowing condcsios wer drwn:

(a) the stove is stable and suitable for use with vario sizes of pots;

(b) it is ea to igites and smokeless;

(c) it is rather esitive to wind; and

(d) the wiks wear out rather quicky.

3.20 Ihe same result was obtained in other W. African counties such as M auriana, werhe the_ntroducto of low power kerosene stoves in 1973 had met with advese conmr reaction. In

198U, thirteen households in Nouakchott were given an adapted Thomas Cu)p, a PET stove, or apressurezed stove to be used for one wweek During that time the stoves were used for food

Kmesm. Stows Pop 20

preparation at least twice daiy. 'e women wung the stoves had no compaints about safety,Inconven;Awe, taste difference, smell, etc. In fact, they waore quite pleased with the stoves andwould have liked to keep then, irrst of the type of keroene stove they had used Ihe sameconcluons could be drawn from cooking demontabions, wher a total of 120 women participated:keosene stoves should be cnidered as alteatives to LPG stoves, for they perform comparabbto LPG stoves, but at a lower cost Unfortunately for them, high power keosen stoves a e notavaiable on the market in Mauritania.

321 However, the PET stove which performed wel in the laboratoty, encountered sevaltechnical problems during tests in Burklna Faso and Ner (1988.89) pa arly incs gtomperatur in the kerosene reservoir and a power drop while operting in high ambienttemperaturs i Niger (1989), 180 kerosene stoves (PET stove) were used by households in threecities (Nianm, Zinder, and Maradi) durng the perod of one week while these households werevisted every day. I reactis have been very positive and some of the most interesting restare presented beow:

(a) 85% found that kerosene stoves were easy to light, and that they started quicklr,

(b) 89% of the sample appredated its kerosene sove, 94% said that they could ue itfor al their cooking needs, and 65% indicated that they did not need to use itoutdoors like they are used to do with their woodfuel stove;

(c) 41% indicated that the cooking times wee reduced

(d) 88% indicated that the stoes did not smoke;

(e) with the use of kerosene stoves, househos indicated that they coud reduce theneed to clean the outside of their pots and pans (70% needed to cean onoe a weekwith their old stove and 9% twice a weekl, whereas this is 0% for once a week andS7% for twice a week with kerosene stove) and

(f) 94% of the howsehokds indicated that the taste of the food was not affected by thekerosene stove.

3.22 After three months of usage, it appeared that only 66% of the stoves stl remaind inworking condition, whe the rest broke down for one reason or another. From the technica: yatof rLew, the stove were not yet good enough for a wideecale n e thoughousehods clearly liked them and were interested in using them In other words, householdsshowed their wiinge to switch to kerone for cooking, even thowugh a suitable stoe did not yet

Km 8mm Si. PIg21

3.23 'Te PET stove, despite further ovements made during the field tests which overcamethese obstacles 32, did not reach a suficient stage of development to want disnation.Nevertheless, some consumers indicated that they were willing to buy and use this stove in theabsence of a better alternative. The PEr stove as tested in Cape Verd& had a higher power output(comparable to LPG stoves exsting on the market in Cape Verde) and was better protected fromthe wind than any other kerosene stove tested, and househwods indicated that they preferred it overthe other models, despite its shortExisting stoves on the market in CaX: Verde includea variety of L stoves and kerosene stoves Howevr, these kerosene stmoes have a very lowpower output, and they have lost their market share followkg the widespread mtroduction of LPGstove

3.24 The TC fared better than the PET stove. After strof the frame of the stove,the TCM prwved to be not only better (from the operational and energ points of view) than thePET stove, but also that it could be considered for d tion. Although the TC]m still does notmeet all of the criteria for a good stove for W. African households (see §2.9), its pefce issuffiiently reiable to warrant large scale co _ns acceptability tests. Its mai draw back is thatthe 1C, only reaches high power levels at the expn of the stove's fuel economy.

3.25 Although the Superior arrived too late in Cape Verde to be field tested under ESMAPsuevion, the Foresty Department agreed to distrbute the stoves and monitor consumersatisacin an a monthly basi Although no technical feed-bdc was obtained this way weneverthekss leart that lighting the stove sometimes caused problems We also learnt that the userswre gonaely pleased with the stove's performanoe. It proved to be much trd than the otherkerosene soves, while its power output was valued sufficiently high for eisting cooadg pracdtca

3.26 A similar reaction was obtained in TunWia in 1989. During a stove acceptdemonstration in Aln Dram (N.W. Tunisia), in which SO women participated, the Superior, as

ompared with the LPG stove, was considered to:

(a) have better stability,

(b) be safer,

(c) be portable, which the LPG stove is not;

(d) to have a higher maximum power, that allows for fase cookin&

In additon, they stated that kerosene was always available while LPG i not, mai it a strongargment for its use under Tunisian conditions.

U_ P. Bu_a aud P. Vir, bmft gm PT Kmawi* B9ams TedinolGp BuudiAdImry 1681 ( se pofto ESA).

.Mws SkeWs Pwa 22

327 Becaw most kerosene stoves are sensitie to the wd, they are usually uod indoorsTherefore, it Is Imortant to deteme their safety with repec to the combsion quality andespcialy onWcerig the poductn of aurbo monoxde (00). Tests were caried out on theThom Cup in Bukina Faso3 aad showed that the stovds CO emisios are low, as its IndeOf Toxic (T " was only 0.31. European standards require an Ir value of about 12 forkeroe stoves. aus, it may be conluded that the Thoma Cup can be consdered as safe witrespect to the production of CO Simlar results were meaured for the imental so-calledREr stove, wher a value of 02 was reached 9.

3.28 Gas leakwes (Methane, Butane) ane detrimental to the envronmet in that they increasethe greenhouse dc Compared to CO emision, metbane is a aor of more hn 10 times mrdetmental and it is therefore im atve to minmize paile leaks. Most of the LPG stovesleaked gas from time to time mainly as a resut of operator err (when coeting the reservoirto the bune, foWtting to ignite immedately the burer, etc), which cannot happen with kerosenesoves. Th chance of such leakage occurring exist with prsurized toves, but only if these arenot sufficiently supervised.. in both cases, the occuee am be m winmalzd through operatreducation

3.29 Additional nironmental problems with kerosene stoves may occur when the reservoirs arenot correctly fled and/or the stwes are not properl cleaned, and keomsen may spill on thegrund. Hweer, the user accpace uveys did not indicate a problem but if ocaring it couldbe solved reatvely ea through operator education.

* _ ood Soveu. Gas ad Ke Stwas in &dg Pmm Feb. s8; Ca_8aues Rapd

*0 11w Ie f TaId&y itnmnIkadcs for di o Imd*of tdo .ao*uila VWs ad Isdeflad astho ratio 'Ofthasaussad p_Puit-g, of cuiat mNioild and cbaes d odd% mi1u by a federf 110.

U -D B M lD dm dN aRd" I on oetrob s Gmn Apdt 19, p. 2 RDI).

4 LOW POWR KEROSENE STOVES

4.1 As mentioned before, most low power kmerosene stoves are found In Asia Past work ontesting kerosene tves in Indonesia had already yieldedinfod mation about the -hrcitics ofthe types availabe in the market Most stoves are of the low power, multi wick type, and have acomparable basic desi. But these apparently simila stov with minor differences cause theperformance to differ widely. Fires due to eqxloding stove are not unommon and can beprevented by better designs Past tests also reveal the eience of a wide rang both In power andefficiency, resulting in a wide variation in their fuel onsumption These resuts suggest that a largescope for improvements eixsL In EDP No. 27 a first attempt was made to link design features toperformance for 20 stoves from all over the world. In its work In Indonesia ESMAP aimed toextend the inights gained in the earlie. report into the determinants of the performance ofIndonesian stoves as a kind of pagr p toto for simlar low power wick keroene stoves.

42 Lemipas, the Indonesian Gas Research Insdtute, conducted ensive tests for ESMAPUon the peformance of 18 kerosene stoves found on the market in Jakarta. 'he work constd ofa detailed description of the stoves followed by a series of tests: power rig tests, efficency tests,fuel conumpti tests, and safety tests. However, as wi be eplained later, of the 18 kerosstoves tested in detai, 11 did not pass the Indonesian standard SU 0135-76 which is based on theBritish Industi Standard.

Wate Ming Tests

43 These tests (see Chapter 3.) showed that the maximm power of the stoves tested inIndonesia ranged from 1.0 kW - 2.0 kW and fon 3.0 -33 kW. wer pcwe stovs exst, but arerarely used in households; the majority of households use the low-powe stovs I uned outdffcult to find a sove with a power between 2 and 3 kW. The miniimum power lees of sometoves were high compared wih the maximum power ratig, and therefore an atnatv wick

setting was appe vi, the wicks entered the wick tubes when the lwer was placed in the lwetposiion. If the wicks would be turned lower combuston woud not continue beoteen the flameholder, but only near the wick at the top of the wick tubes, while the fames would sti be stabluThe minimum power ranged from 0.2 kW to 1.9 kW, which resled in turn down ratios rnginfrom 1.0 to over 4.0.

4A Efficencies of the stoves varied from 33% up to 51% as meaured repeatedly througb watrboing test I was striking that no relation eisted between the prie or the brad na nor thetp of produce (fatoiy or artian) and effiency. IThb means that neiter rep norconsumers are able to identify high effcienq stove

4.5 To better understand the results from these efficency the efficiec wasplaod aist the power output of the stove (Figure 4), and the ratio betwoe pan and burner

USa Am= 3; TofesaLm d sL Sft f6 LM*u MW s).

K ams" Pa 24

diamte of the outer famlder (Figre 7). As is shown in the figures, the efficiency of thestove is hier when the power output is kloer, as weU as when the buner is more compactcompared with the pan diameter. The influence of using a larger pan on the efficiency of a stovewas already shown in 37 but that in addition small burners should be preirred Is a new findin.A compact bun means that the wick surface is small, resulting in low power levels of the stove.However, when combined with hiher effiiencies this low power ratig does not necessarily meanlgr cooking times for the same amount of food.

Safety tests

4.6 The safety tests established the temperture of the seval stove parts, duing a testigperiod of fwe hours To that end, each stove was lighted with an almost full resevori; the tesswere stopped after five hours or if only 10% of the initial ke e was let Every hour thetemperatures and weit of the stove was registered. According to Indonesian standards (SII 013576) the tmpature of the reseroir when 10% of the kerosene is left should be macimum 50CThe tempeat of most stove parts regularly touched by the operator shuld be maxdmum 80C,and the remainder of the stove's surfice (excluding the burner) should be maxmum 94C.

4.7 Tempatures of 18 wick stoves were *,, tul

measured and k was shown that a majority of the soves did not comply with the quality standard: 5*

thet eMPet of 50% of these stoves in the 40servoir was in awes. of the flash point, and 10%

of the stove had often touched parts withtem atures in mee of 80 *C. Consequently, it 2D

Sommended to consuct a heat shield to uoreduce the tempature of the reseoir. .D

4.8 As far as other safety aspects are power output (W)concerned, such as reservoir constton and Rme 4: Reaio betw pow outt adthidmes of ml or stability when slanted at 15%, dffiC7 of suethe stove showed beaer results. In a theseaspe the stoves passed the test.

Controlfed cookin=

4.9 The reuls of the controlled cookng tests shown in Table 6 demonsrte that udsig a higpower stove can lead to considerbty hie les of fuel use, ae for svm with the sameefficenc. They also demonsrte the potential fuel savings which could be obtained from urniqgthe stoe power down during selected cooking operatons, and fIrm minimizin the water used forrice steaming.

91 Peu 27, BD? 2?, Worl Buak MR.

Euremin stove VPeg

4.10 Inf~gip 5 thespecific fuel umpton[SFCj is plotted as a .. '.

function of the power of the .stove. The SFC i n eases~

with an enlargement of thepower output In Figure 6 .. ;the tim requihed for thecooking of a standard meais psndted. Ls time isneeded to cook when the ; t N ~.power of the stove is 1 .*

increased. Thee relations . . ~..~ canh be explaine as follows &

The preparmtion of the rioe th i n l cmnsst for about 50% of ~ $4 s'.:...

the time of heating up and i .r 50% of owneing. uthe faY1Y;durtion of the heating up o >ld•. Ie period is diecty inf luenced f a m If t .s. .

by the efficienc [P.. andE.j of the stove, Le. thehighe P. and mea. are theshorter this ped wil las

4.11 I'he efficiencies obtained during the SFC as Function of Stove Powerwater boiling tests showed les variation than c Pctic Fuel consumption m IlmJ)

the power levels Tfhereore we may conclude 7

that the most impoksn factw tha influencesthe dVItioof theheating up petiodois P of ofthe stov4L De more power is used the foastthe heating up period is completed. The 2simmer period is constant for ai meals. f thi Vis done with lower powl than P. lessf i

1.5 8 3 2.1 4is used. 'hese results were confirmed for both 00tof et" (iekW)

the entire standard meal and the cooking ________4__p_

proces as wellas for rice onl.U

4.12 The use of stoves with high efficiencydoes riot necessaril mean that lkw fuel is sed.Stove VI, with an efficiency of 3096, does not signficantly use more fue for the entire cooking taskthan stov Il which has an efficienc of 51%. This is partl due to the variation in consumebehavior, specifically, to the amount of water Used. The water lef over with stwoe VI is mudi moretha the wate left over with stov IlL AIxo, the amount of cooked riceb Is are with stove MI tha

KerWus Sism" hPar

with stove VI. The amount of uncooked rice wasientical, ho a. Ibis illuatahthe difculti Cooking Te as Functin of Stove Powerencountered with compaing water boilg and controlled cooking tests.

2

4.13 There wee no specific studies done which s

testel the consumer acceptability of kerosene e _ 4

stoe in Indonesia because cooking with kerosene ., * W)

is a normally accepted practice. Al of thekerosene ves consderd in this rport are inactualy use, even though for example, 60% of the e 6stoves failed the laboratory safet tests.

Theoeial Model of Time and Fuel Sav

4.14 A model of houehold cooking and water I -_heating was developed showing how different SC

fctors affect daily kerosene consumption for a so -typical household starting with a typical stove. Iheresuts of a sensitiviy analysis usig this model are 4

shown in Table 7. Looking at the stove perforce 30

lione, rouh 1/3 of kerosene consmptiondpends on efficenc and roughy 1/3 on power(the rest being unexplained: consumer behavior).Thi implies, for example, that if efficienc e

ieas by 30%, kerosene consption wil I tS 2 23 3 i5

decrease by 10%, and cooking time wi decrease m 7: Relat btw te e5duq of thsomewh_k However, if this efficiency cIeas is stvs and to rtio of pan sad bu_n dim

accompanied by a power decline of 30% (leavingthe power delivered to the pan roughly constant), kerosene cspti wil dreas by 20%, andooking times will not have altered.

4.15 The two more user-dependent factors stove power a4ustmet whl cookin and thequantty of water empyed for seamin rice, were alo modeled. If power is dewesed by two-thirds during both water simmering d rice steaming) after the water hs alry bee br tobo4), the households daily kerosene use would fall by about 10%. Ahernaely, f the moun ofwtr ued for stming rice is dereaed from 13 to 03 liters, a 4% of the daW krose usecoud be saved.

4.16 Saving of rougl 25% in kerosen consmption can be achieved by combding efficienqinpyovno_ts and maximum power reduction with a better tun-down rato and the use of leswater for rice ataming Specifically, this would involve a decLine in mammm per from 2.0 to

45 tunn theE 1|l| 1

andorant,& pandr-

amut thestoe isd foralogtm rmele e oe svs,iws~~rImba lodace teoe tb0a n s i nl e fiinr"

Ibo this.t s o e &

.* dao sd toav we 18 p

NKaI.w Stew Pe4P 2

4.18 Tho two apcs onsdeed weae an air flow resttor and an adjustable pan support Itis shown that the air flow resiwor can impro the eficey with 5% to 15%, whie adjusting thepan sppot position can imp the eicieq with upto 25%.

4.19 Air flow thbugh a keros_e sove is requied for the combusion of the kerosene vapor.Therefore air has to enter the combuson zone via the sheld and the outer flame holder, and theinner fame hoder. If too much air is drawn into the stove via the inner fame holder, relatiymore air wi escap via the hole in the top of this fame holder. Thi wil result in a wider flameplume above the stove and c y the efficiency wil be lower.

4.20 Tbe eficenc is also ;nleced by the tempeat of thoe ases leaving the sov T'heaage tempatur of the gases wil be lowa if more air is pumped through the stove. it is dearthat the air which goes to the Inner flame holder, which is closer to the pan, is more important inthis respect than the air going through the outer flame holder. A way to reduce the flow throughthe inner flame holde is by placing a flow restiction at the bottom of the flame holder (or at thetop of the wick holder). Two complete and elborate tes serie on the inluee on the efficiencyof a stoe with and without a flow restiction were carried out with the Dua Saudara stove. Theorgal desin which did not have any fow resitnce at al in the inner flame holder, was modifiedwith a zinc plated metal sheet in which holes were drled. The net reut was an increase inefficiency a a result of the flow restriction. The PET ste also had such a restictor in its design.

4.21 Another important result fhm these tests with and without flow resticton is the reductionof the tempeaue of the keae in the reservoir. The flow restriction act as a radiation shieldbtoween the hot inner fame boder and the top of the tank and the wick pipes. Other modificatht wer tested during the Lemigs work (adding wood insdation beneath the wlkhokder pate;

dg a restictor and holes in the shield) did not resut in any sgnificant influence on efficiencyor safety M.

422 Six ofthe tested kerosenetoves had ap supportwhichwas ns d of metal andwasplacd an top of the stove. Sone pan suports are fixed (of stoves procured by artisan), whtathers are no.. Mm movable pan support has two posions One is the panw positi where thewelded cidres of the spport ar above the joer ir. Te other is the so.called w posi,beoaus its purpos is to provide tra sup for the use of a wok, where the weded circes arebeneath the join ron. ibb means that in cae of the pan' position the pan rests on the rin&while In case of the VW posion the pan does not and sin deepr into the sove.

123 lie efficency tesssod that wher pots had been ading on the ' posion tat thenmarW affidea were sigficandty lower tha those in VW posiion. When on the sam tove

' LaaS VP 614."

Kam St"" Par 29

the pan spport was revsed from ' position to 'wole posion ther was an increase iefficiency ranging from 10% to 25% '°. The are many more stoves than were teted, thus noreal quantified dimensions of the changes in canstuon could be given -Howeve, for eah stovt these dimensios can be determined separat*.

4.24 Ihee two simple changes would have a sigifin ect on kerosne consmption ifadopted. Furthermore, they were uncovered in a relaively dsort time: it is likely that similaraving could be obtained from other design changes or, for example, changing the quality of the

Wks used I. A program to improve the quali of kerosene stoves can be expected to producea variety of keroene saving possibies during the couwr of its work, pecialy if suffietattention is given to applied research (as cpposed to simply enfrig standar, for example).

425 Both fatory and artsanal stove production are amenable to the m identifieddu*g the course of this study. Factoies, beIng both larger and having more ready acoess tocapital, are a more obvious target. Even the smallest artbanal produce should, however, be ableto add a flow restrictor and produce stoves with efficient movable pan supports, and some evn do

4.26 Materials are the major cost item for both factories and artisans. For artisas reliablityof materil spy is also crucial. Tis could provide an opportunity for govenment assstance,linked to a stove Vimovement program 4a. In addiion, fitoy prodon, being moestandardized and easily acoessible, could be affected through official stove standards. But the samecold also hold for part of the artianal produrs, a major part of whom are often dustered in onearea, sometimes making the same model of stove.

AU dingo in .fieq ant. rlaie due a 10% effimq ibona maw dmi *fo, soy, 40% to 44%,

a1 8e& V/Is i9s p. 8-10 dmu hwwi s an be btto jwowP p_daguh zWpM decad by WON atlag uarad doe bomttdom Sudm thaw ande d the wIholder. Ale%, by givig the vIt a pioweftt ala gin

For adetihdprposah frnda pwun-WAP,I Jdaose Udn liomid ns SUu<W*vd1- Us R_qt, p -9, md vL 2 Appewdv4 A4wadm 2.

XNOusigns A8p 30

C CONCWSIONS

5.1 In the pree chaptrs we have reported on the reults of field and laboratoty tests ofkerose stoves in Indonesia and W. Africa. The anabl shows that there are simple, butimptant, techical possibilities to improve the quality of exist stoves. Also, that, If adapted,there are keroe stoves that can be marketed in those parts of W. Africa where until nowkerosene stoves have been rejected by the market as an alternative to cooking with wood orcharoaL Furthemore, that there are still non-tec obstades tht need to be overcome tomake use of these findingS Ihe challenge for polcy makers in the developing world is to translatethese technical and economic opportunities into sccesf stove programs.

52 The test focussed on low power stoves (<2.5 kW) and high power stoves (> 25 kW). Powerand efficin varied considerably among the low power stoves Both consumers and nufuare inorat of the stoves' fuel economy, and neither group can ascertain this tirough physicalispeco The high power stoves were both wik and presurized stoves. Here also there is adifference in power and efficienc), and especially in the turn-down ratio.

53 Ihe report confirms earlier findings that the determmants of fuel economy are (a) maximumpower (P.), (b) the ratio between P and Pw the so.called turn down ratio, and (c) fuelefficioes E.. and E;t. In addition, the report illustrates the importance of (d) consumerbehavior, as a determinant of fel economy.

5.4 In case of lwgm stoves the rveport concludes that, above all, there is a need for aproguam of standards and endorents with acompanying spport for the Improvement of themanufatudi g of kerosene stes. in addition, only minor and inx e te changes wouldbe calle for. The case of v is less staighw The 1T wick stove, with

ations, has be sown to be a marketable product that meets with comer atis on. TheSuperior, a pressuied stove, ony performed atisfatily and met with conumer satsfaion inTuniia and Cape Verde. Additional, more laborate, market studies are required to confirm thiand provide cosumer's feedbacL However, eewhere in W. Africa fuel problems bedeied thesmoo perface of the Superior. Therefore, more work is needed to ideW whether thepoblem here is fuel related or a desig flaw.

5.5 In op ona terms the folowing Iiw-cri1m nLtsim can be drawn:

(a) It would be desirable to initiate a stove manacturing quaity control progrm.Such a progam should have two components One for fctoty produced stoves(both impot and local ones) which wi emphasize sandds anderThe other for artisnally produced stoe which require dirct support in improvingtheir prodution process Factories are more ameable to standards anendorsemens and produe an a larger sca Ardsans are not easily amable tostandards. Mme progamm, therefore, should be initially be imited to large groups ofartbans, who may already be iovved in gveTAmet spported activities;

K_inm st,o ;a p 31

(b) Programs should be undertaken to increase consumer awareness and solicitconsumer partiipation in the kerosene conservation progm. Without pressurefrom consumers it will be very difficult to cohvince produer to inprove stovequality. Standards and endorsements must be undertood by the consumers as welas producers, so that consumers can assess the costs of purchasing a sub-standardstove. Simultaneously, the knowledge and preference of consumers (or theirrepresentatives) must be tapped to insure that the standard program is appropriateto their needs; and

(c) Finaly, consumers should be made aware that a fuel efficient stove can only realizeits potential if it is used properly. User dependent actors such as using the turn-down ratio and the quantity of water used for cooldng can considerbly effect fueleconomy. Consumers, therefore, should have ace to information about how tocook more economically.

6. In addaion, the following technical conclusions are submitted:

(a) the TCm is a good stove for those consumers who prefer a high power stove. IheSuperior, although it got good marks from women in two countries, stil suffers fromtechnical problems which adversely effected its performce. These problems aremost likely fuel related, because in Columbia this stove performs wel when usedwith cocinol;

(b) there is a need to create an after-sales service for the repair and maintenance ofkerosene stoves in those countries where Governments or private sctororganizatons intend to launch large-scale kerosene stove promotion schemes. Thecreation of such a srvice need not be epesie if one makes use of eaiting repairfaities who will participate in the promotion schemes, attracted by the proped of

new customers;

(c) additional applied research is required as an integral part of a kerosee steprogram. This rsearch should be undertaken by a single research center withinformation dienation to interested national or intenational pivate seorgroups or NO0s. This research should be aimed at maldng incrementalimprvements such as improving the flame control machanism of kerosene stovesthe effect of different quality of wicks on stove perform, and the fuelparameters for a better performance of the Superi stove; ad

(d) finally, as the tests for specific fuel consmpdon have demosrted, kaeos stovacan be quite competitive with LPG stoves. Further pnements in the quality Ofkerosene stoves (btter qualit cks, better flame control mhanism) will spplythe fnishing touch

Km stem Pag 32

Ann I: Financial Comparis of Dih*eot Almatle for Cookg

In this Annex, different cooking opdons are compared from the end-users point of view. It Isaumed that the usee diet is not a fuon of the fuel used (which probably is an over.smplificatn), and that each optio use a similar amount of end-use enea (approimately 22MI/perwn/day).

In this anali, actual 1990 retail a are used kom W. Afican countries as published in 0. Seea summary Table Al.l below:

Table A1.I 1990 FUEL PRICES IN WIST AFRtICAN COWTRIES

lurking Nail Mwuritania Niger Segl Chad avero

Wood 20 20 20 20 20 20dcaoal 45 SO 123 60 60 66kero1en 200 300 96 131 231 250 201

LPG 250 314 172 308 220 509 296

It is lear that kerosene and W pnces vary quite a lot between the different countries. LPG ison aerage 50% more expensive than kerosene wich can partly be explained by the bigher costsfor W distribution than for kerosene, and partly by the fai that kerosene is genery less tedthan M. In any event, in the analyi we look at finanil rather than economic cos since weare lookng at the end-user level rather than at the national economy leveL If an economic analysiswere done. the difference would be that the costs of wood would be higher than is reflected byfinancial costs (reflectig resource value + replacement costs) and consequentl, this also holds forcharcoaL

Ihe following Table A12 shows the fuel characteritics, taking average retai prices from theprevious Table A1.1.

Tbtle A1.2: FUEL CNRCTERISTICS

reteft price NO/kg Us$/kg USO/kiF.CFA2kS USN

ood 20 61 19 0.06 3.19dmerool 68 205 31.0 0.20 6.61ke1o 201 610 43.5 0.61 14.03 1)

LPG 296 895 45.7 0.90 19.59

1) conveslon tactor sed: O.t kg a I liter

Table A13 shao ilvestment cost for the different doves, dteir enery effdiccies and expoctedaverg lifetime, and annulized equipmt costs.

KiossueStove Pap33

Tale A1.3: sTW CARACTERISTICS

costs .n, life wvltyus$ d1 . yer VW

wood tr 3 15X 1 3.3wood lpr 6 281 1.5 4.5

charood tr 5 221 1 'S.$daoal tr 12 35X 1.5 9.0

krosai 18a 451 4 5.?Itp 35 552 5 9.2

Table AlA combimes ai data from the prevous three tabls and shows the totd anual c of thedifferent cooking optins availble to housds It also ge dat for dai Iol use, primayener use, and casb expenditures. II analsis hows tat (i) aual oe cos an le th 5%of the total annual cookong fud bill (eEcudg food); and () (improved bkom stove poidthe cheapest option, although kerose is of the same order of magnitude as charoal wih atraiional stove (See Graph AM.l).

it must be said however, that the tuation ages drstic with the relatie fuel prie strcturein each counlty, see Graphs A12 (Maurtania) snd A13 (Nger) wich show that keroee is themos cost effective option for Mauritania, and improved wood stove is the best cost effective optiofor Niger.

Table £1.4: MNtRL COST FOR COOKING

kV1dy NJIy USVdsy sto M

wood tr 7.9 150 0.48 3.3 115 1wood IW 4.2 SO 0.26 4.5 94 9

cdar tr 3.3 418 0.68 5.5 247 M2daol r 2.1 23 0.42 9.0 155 164

kemsm 1.1 50 0.70 5.7 256 U2lpo 0.9 41 0.80 9.2 23 302

17 in primary Mi6w teru; cv;Passtion otf:teRe y 15X.

Karma stone Pap 34

FIGURE 8

BREAKDOWN OF TOTAL ANNUAL COOKING COSTFUEL + EQUIPMEW

350

0 n- -¢

wood tt wood impr ¢haoi tr charcoa bnrkrme lpg

stovre modelsfOh lut equipment

Kgrose stoe Pap 35

FIGURE 9BREAKDOWN OF TOTAL ANNUAL COOKVNG COST

FUE + EQUIMNW ItU*n

4sM

4 ^ Mauritania

64W

wot ww wowt d"w kmm o

stove models

rm ie m

FIGURE 10

BREAKDOWN Of TOTAL ANNUAL COOICNG COST

I H

dt wo hiW dwooutl' kwt hs 1

stove models

C]" q

Kimu_ 8wi POV36

An II Testig of Presuubad Stov

1. In vapor Jet bunes, krose J aabe at hie¢ than atmwpheric presue which isadleved by a hermet sled fuel contaier which is brought to preue with a sahandpump. Becuse of the pre e difference, the keone rise and arrives in the hot vapoerwhere it evaporates and leaves through a mall nai In a high veloc jet In the free Wsebete the nozle and de flame hoade/stabilizer, the jet mixes with air which enables the gsmixture to burn ith a blu fame.

2. Detail de- Tabe A2.1: ummary 1of pressurized stovesping bes pefa- .

mance of presu-.bed burers aegien in Table A2.1. '".

Tbe 8tm,

output of a vapor b . b.

unc dotn of the itvapor t.enaomtd

o 8 a sond nWehcm ihthe stvdpre==ban

difference. 'There. .w

toht the prsur i tbcan be easilybuiW-up as well aseasil be cOntroIed Most of the handpumps which came with the stoves showed a poorper1formance. Becaue bicyclepumps sometimeshave abetter performanc tanhand pumps,inIndonesia one can oten see a bicycle pump connected to the stove.

T113 Is

4. Thequaityof the nor4sappered to beetremeyimpor. Atboth forthe promneandfwr the safey of opertin the stove A burr in one of the norzles caused the norzk to kom acloud of keromee vapo instead of a vapor jet. For safety reason this nockl had to be excludedfrm further tating. A secnd norile which came with the stoves was cloked-up completely andcould not be use This imple albo that the quaIty of the keroen should be sufficiently high towarrant a satifatryprfrane

Kwfaine StomSPS

S. Firstly, the power ranges of the two burners selected (Super JLH and the Bee & Buttely)wer detemied for different nozle sizes Secondly, the efficency was measured as a function ofthe power and the 'pan bottom - burner head" distance. It was esential to have conto over thepower output of the stove, which was done with a presue governor valve. When a stove is usedwithout such device the pressure will drop as kerosene is consumed, the air volume of the tankices and thus the pressure and power will drop. Ihe fuel tank wa plad on the electronicbalance to record the fuel weight los; the time was recorded with a stop watch For the efficiencymeasuements, an aluminum round bottom pan (size 3; diameter: 300 mm) was Slled with waterand hung above the bumer at a fixed ditance.

nle porout

6. Ihe eximents with the burners (Super JHL; Bee & Butterfly) were performed fordifferent noze, diameters. The pressure was vared firom 5 kPa to 200 kPa, which refects thequalit of the pumps. Each exrment lasted about 15 mmnutes in whih the presre was keptconsant at selected values The exeriments with the Bee & Butterfly were performed twice. ITeresls with the noae of 0.65 mm could be reproduced within the ental acuacy. Ontheoretical grounds it was expected that the stove would give a higher power outputh the 0.80mm, but the experiments showed the contrary.. However, during the series with the 0.80 mm nozle,the flame was blon away from the burner, indicating that the nowzle was damaged. Tbis showsthat in order to obtain a maximum performance, the nazle has to be in oent shape.

7. A series of expeiments was performed to determine the influen of the power output onthe efficiency. Ihe distance between pan and burner was kept constant at 6 mm. Ihepower ccurve meaured with the 0.6 mm nozle lies a few peentag points bigher. Itindicates that there are other parameters besides the power and the 'pan - bunee distace whichare important. Consequently, al buner dimensionsshould be chosen according to the nodze sie

Emdm

& On the bais of these tests, the SUPER JlHL was TAble AZ.2: Power Output - Nooszeselected with nozzles of 0.4 mm and 0.6 mm for the Diameter Combinationseffiincqy tests Taking into amount the quality of thepump, the power range of e stohe /nozdesre Ov in Table A2Z.

* Bmurer Distace

9. In a seond saies of f npriamets, the power wabeld constt while the dist (d) bewee burr and 1.the pan was varied Th result of the tests deary showth reduction of the effliem with iaeasing 'pan - burer' diance. As was ezxpe the

Kareo sawSove PaOP 3

eperiments with the 0.6 mm nozhle showed higher effiiency numbers. However, directcomparison is not possible due to the different power levels used in the series.

10. TIe vapor jet burners tested belong to the classic primus type stoves. For a given pressein the kerosene tank, the power primarily depends on the diameter of the nozle. The theoreticalrellation between pressure, nozzie diameter and power output which depends largely on the squareroot of the differential pressure and a temperature component, was confirmed by measurements.Ihe objectives of the work were to design a stove with a maximum power larger than 4 kW.Taking into account the quality of the pumps which came with the stoves. this means that thenozze diameter should be larger than 035 mm. On the other hand, the nazle size is restictedby the minimum power requirements. Ihe epeiments revealed that a minimum power smallerthan 1 kW is not fea8ible with a nozle of 0.6 mm. Mus, the diameter of the nozles to beconsidered range from 0.4 mm to 05 mm. The vapor jet burners are very sensitive to impurities(e.g. litle sand pariles) in the kerosene. They clog the nozzle easily. The larger the nozziediameter, the less important this problem. This finally leads to a nozzle diameter choice of 0.5 mm.

11. Once the nozzle diameter is known, the other Table A2.3: Characteristica of a 4 kWburner dimensions can be found using the empirical presurized burnerexpresions. The dimnensions are sumnmarized in TableA2.3 below. The choice of the noze described above MMEimplies that It is not necessary to improve on the quality # 'I.:.:,.:of the pumps. t suffice when the maximum pressure edelivered is than 150 kPa (1.5 atmosphere). The iefficie nymeasurements dearly showed the influence of .~

the distance betwee pan and burner head. On the onehand, this disance should be kept as small as possibel .. ..

while on the other handt the pans of different siz shouldnot be allowed to touch the burner.

Annex m (Stove Model)

Wick Stoves

FIGURE 11: Thomas Cup 20

od~ ~ 7G

LJ

sOw 8 rup D

FIGURE 12: PET

g | S g I | 11= | _ _ S S r S .! illll | _11111 | 111 1111 | II il_ | a_a _ | - aN ral _ | _ _ a S N gs! _11 | _ l * 11 I

_ f _ X X * s !. _ W I_ l IL | 111 I

_ aN _ _ S s s -_ sg _ _ W gs S - .I _ | B s | - I- S N E E E -

-=id_l R _ C_ e a |-

_-i ., X X | |_ g I _ | | * -

_ - _ fi fi *-a 1_ f 1 | *g_ a a_ _ a asil * _

_ ag _ _ | | | g_l | g _ | , | *-_ 11N | . X | 111_ S _ s i E E -_ - _ I I - * -_ - I | I | *-__ - _ I | | | |-w__ w I | I | *-_-| _I | g g | |__ * _ I l I | * S_ 11 _ I l I-* 1111_ 11 _ I l I-* 11111i_ 11 | ! l l - * e= 111 _ I I I 1113 * -_ - _ | l | | * s_ _ s I l I 1 * 1111__ I l I-* lilll__ | | l 111 | 1111_|1 I | | 1 11 ilgill__ I | |-|-____ I I | | | |____ I g I g g-I S I 11S Illi glill____ l I l S R-

____ I i | 1|111 11|1 igll_ | g fi asa S-

____ F B g g N N

_.

Pressurized Stoves

FIGURE 13: Prlmus

4

Pan support

Durner-Xt

Pressure relfef valve-

Keronew tukli

FIGURE 14: Superior

CL?~AMWY., w

I

I I0

uTIOddQz :SI 3nnfOI

I" I[. . -- .-- . _I

sw~~ ~~~ T I

lm l~~~~~~~~~~- rr t I I B 8 r I~~~~~~~~~~

b I I 0= I 1> ~0 IFl

I-A4L-'T 1t e. Ce, 11 tX I~~~

. L \ 4 [ _\<t |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-

w.

0~~~

- -~~~~~~~~~~~~~~~~~~~P4 44

Cbarcoal Stoe

FIoURE 18: MaIache

FIGURE 19 Sakknal

b_ . ,~~~~~

_ [-:: . 1b. - ~~~I ; - - \/d a~~~~~~

.1 _ _ _ _ _ _ _

FIGURE 20: Rondereza

FIGURE 21: Kengo Jio

o~~~~~~~1< ~~~~~~~~~~~~0

1'-- 1<

u...Stm Pa8p 46

Wood Stoves

FIGURE 22: Malgche

FIGURE 23: Mal Sauli

=~~~Iw~ r I

ft X9low .ram