Ukubuyiswa kwengxolo
Iindawo zokugcina amandla, iifektri, iziseko zezinto ezilahlekileyo kunye neendawo zokugcinwa kwedatha zikhupha inani elikhulu lelanga elinokufudumeza umoya namanzi ngosuku. Okuninzi kwalo kungafudumeza amakhaya endaweni yoko. Akukho nto ingakwenza umbane. Kukho isizathu sokuba kutheni, kwaye apho ukubuyisela kusebenza khona.
Helen Ltd / Wikimedia Commons (CC BY-SA 3.0)
Ngaphantsi kwegadi eHelsinki, kwiintaba eziphakamileyo ezitywinwe kwisiseko selitye, umgca weepompo ezinkulu zobushushu uthatha ubushushu ukusuka kumaza acocekileyo olwandle kunye namanzi abuyela kummandla womsebenzi wokufudumeza, kwaye ubeka kubushushu bendawo obushushusa amakhaya. Ifektri yaseKatri Vala, elawulwa yinkampani yombane yedolophu iHelen, yavelisa 570,000 MWh yobushushu ngo-2017 ukusuka kwipompo zobushushu ezikhulu ezintlanu, kwaye enye yesixhenxe, eyongezayo ngo-2021, yayilindeleke ukuba ikhuphe le nto ibe ngama-200,000 MWh ngonyaka; amandla ayo afike kuma-123 MW (Wikipedia, Energy in Finland, citing Helen, 2018). Ubushushu belukhona. Yasetyenziswa ukutyibilika elwandle lweBaltic.
Ubushushu obulahlekileyo buye bube yi “ndawo yomthombo wombane” obukhulu akukho mntu ubala. Uvavanyo lwango-2016 luqikelele ukuba 72% yengxolo ephambili yehlabathi ilahlekile emva kokuguqulwa, ikakhulu njengefuthe, kwaye ukuba 63% yamaza obushushu agqithisileyo angaphantsi kwe-100 °C (Forman et al., 2016). Inani lesithathu libalulekileyo. Ubushushu obupholileyo bungekho kusetyenziswa ukwenza umbane kwaye busetyenziswa kakhulu ekufudumeza iinkalo. Eli phepha lichaza ukuba kutheni, kwaye yintoni efunekayo ukuyisebenzisa.
Yintoni
Ukubuyisela umva ubushushu obulahlekileyo kuthetha ukutsala ubushushu obuza kukhulula inkqubo naphi na kwaye uyinikezele kwinto efuna ubushushu. Iifomu eziqhelekileyo ezintathu:
- Ukusetyenziswa ngokuthe ngqo. Amanzi ashushu okanye igesi evela kwifektri, kwisityalo sokutshisa okanye isitishi sombane sidlula kwisixhobo sokuguqula ubushushu ukuya kumjelo wobushushu wendawo okanye enye nkqubo. Le yindlela eninzi yeDanmark neSweden yothungelwano lobushushu baqala ngayo.
- Iipompo zobushushu ezikwindawo epholileyo. Iinqanawa zokucoca amanzi, iindawo zokugcina idatha, iivenkile ezinkulu, iitikiti zemetro kunye namaqondo obushushu okufudumeza amanzi aphakathi kwe-10 ukuya kwi-40 °C kuphela. Ipompo enkulu yobushushu iphakamisa ubushushu ukuya kwi-60 ukuya kwi-90 °C ekufunekayo kuthungelwano, usebenzisa amandla angaphantsi kakhulu kunamanzi ashushu.
- Ukwenza umbane. Ukuphuma kobushushu obushushu kwi-kiln, i-furnace kunye ne-injini, ngokuqhelekileyo ngaphezulu kwe-200 °C, kungaqhuba umphunga we-turbine okanye umjikelezo we-organic Rankine (ORC), i-turbine encinci esebenzisa udaka olubandayo kubushushu obuphantsi kunamanzi.
Indlela esebenza ngayo
Ixabiso lobushushu limiselwe ngobushushu bayo. I-kWh enye yobushushu kwi-30 °C ne-kWh enye kwi-600 °C zilinganayo ngenani lezixhobo kodwa azifani nomthombo ofanayo. I-Carnot efficiency, isiqithi sokuba nayiphi na i-injini eguqula ubushushu ibe yimisebenzi, yi η = 1 − T_cold / T_hot, ngeqondo lobushushu kwi-kelvin. Ngemeko-bume kwi 25 °C (298 K):
- ubushushu kwi-30 °C (303 K):
1 − 298/303 = 1.6% - ubushushu kwi 90 °C (363 K):
1 − 298/363 = 18% - ubushushu kwi 300 °C (573 K):
1 − 298/573 = 48%
Iinjini ezinyanzelekileyo zifike kwiphesenti engaphantsi kwezi zinto. Iindlela ze-Organic Rankine, eziqhelekileyo ukukhethwa kokufumana umbane ovela kubushushu obuphakathi, ziguqula ngokuqhelekileyo malunga ne-5 ukuya kwi-20% yobushushu, inyuka ngobushushu bayo (Quoilin et al., 2013). Ngaphantsi kwe-80 °C, ukwenza umbane akusoloko kufanelekile i-injini.
Iipompo zobushushu zisebenza ngendlela ephindwe kabini. Isithuba sepompo yobushushu si COP = T_hot / (T_hot − T_cold): xa ilift incinane, kukho ubushushu obuninzi kwiyunithi nganye ye-electricity. Ukunyusa ubushushu bendawo yokugcina idatha kwi-30 °C ukuya kwi-80 °C iCarnot COP malunga ne-6.4; iipompo ezinkulu zobushushu zifike malunga nengxenye, malunga ne-3. Ngoko 100 kWh ye-30 °C yobushushu obulahlekileyo kunye ne-45 kWh yombane ivela kwi-145 kWh yobushushu benethiwekhi. Umbane awulahliwanga: uphela njengobushushu kwakhona.
Umgama usinye isithintelo. Ubushushu bubiza kakhulu ukushenxisa. Iipayipi, iinqanawa kunye nokutywina zibiza kakhulu nge-kWh kunezintambo zesithuthi, kwaye amanzi ashushu alahlekelwa ngubushushu ngexesha lokuqhuba. Ubushushu obulahlekileyo bubalulekile xa umsebenzisi wobushushu ehlala kufutshane nomsitho, okanye xa umjelo wobushushu sele uqhuba ngaphezu kwayo. Iinethiwekhi zexesha elidlulileyo “zohlobo lwesine” zisebenza kwiqondo lobushushu eliphantsi (elingama-50 ukuya kuma-70 °C) ngokuchanekileyo ukuze kusetyenziswe ubushushu obuphezulu obuphantsi (Lund et al., 2014).
Ixesha liyesithathu. Isiko ledatha livelisa ubushushu ngonyaka wonke; amakhaya afuna uninzi lwawo ebusika. Iinethiwekhi ziyilungelelanise le nto ngokugcina ubushushu, ezinye izityalo zokushisa kunye nonyaka oshushu ngokususa ubushushu obungenakusetyenziswa.
Iinjongo
- Iqondo lobushushu. Ininzi yenkunkuma yobushushu ipholile kakhulu kumbane. I-Carnot equation ayikwazi ukuxoxwa.
- Umgama. Umgca osuka kude nakweyiphi na isixhobo sobushushu awunaxabiso, nokuba ukhulu kangakanani.
- Ukungafani kwexesha. Ubushushu beshishini kunye nendawo yokugcina idatha buhlala; ubushushu obufunekayo buxhomekeke kwimozulu kwaye buphezulu ngemini ebandayo.
- Ukuthembeka kunye neekontraki. Umjelo awunakuxhomekeka kwifektri enokuthi ivale okanye kwisixeko sedatha esinokuthi sihambe. Iikontraki, ukhuseleko lokusebenza kunye nokwabelana ngomngcipheko zibalulekile njengokuba kunzima ukuyila.
- Ukusebenza kakuhle kuqala. Ubushushu obulungileyo obulahlekileyo lubushushu obungenakuveliswa. Iinkqubo ezingcono kunye neeseva ezisebenzayo zinyusa into efumanekayo yokubuyisela, kwaye le yinto elungileyo.
Iiprojekthi ezibonakalayo,
| Iprojekti | apho, xa | Umgca womthombo wenkqubela phambili | Izinto ezigxininisiweyo |
|---|---|---|---|
| Ifektri yobushushu nokushisa iKatri Vala | Helsinki, eFinland, ukusukela ngo-2006, | Amayeza acocekileyo kunye nendawo yokufudumeza amanzi, iipompo ezinkulu zobushushu kwiintaba-mlilo | 570,000 MWh yobushushu ngo-2017 ukusuka kwipompo zobushushu ezisixhenxe; enye yesithandathu ukusukela ngo-2021 idibanisa ukuya kuthi ga kwi-200,000 MWh ngonyaka; malunga ne-123 MWuHenry, ngo-2018; I-Wikipedia) |
| Imeta Odense data center kunye neFjernvarme Fyn | Odense, Denmark, ukusukela ngo-2020 | Ubushushu beseva obunyuswe ziipompo zobushushu kwinethiwekhi yedolophu | Injongo: 100,000 MWh yobushushu ngonyaka, eyaneleyo kumakhaya angama-6,900 (Meta, 2020) |
| Iindawo zokugcina idatha | Stockholm, Sweden, ukusukela ngo-2017 | IStockholm Exergi ithenga ubushushu ukusuka kwiziko ledatha | Inkqubo ye “ishishini lendawo yokugcina idatha apho akukho bushushu bulahlekile” (Stockholm Data Parks) |
| Iindawo zokugcina idatha | I-Finland, iSweden, iDenmark, iNorway | Imodeli ye-potential | Ubushushu bendawo yokugcina idatha lunokugubungela inxalenye ephawulekayo yokufudumeza kwedolophu emizini yaseNordic ukuba amanethiwekhi kunye neexabiso zivumela (Wahlroos et al., 2018) |
Iimpawu ezimbini zenkqubo zibonisa apho oku kuqhuba khona. IJamani ngoku ifuna ukuba amaziko edatha atsha aqala ukusebenza ngoJulayi 2026 asebenzise kwakhona i-10% yombane wabo, onyuka ibe yi-15% ngoJulayi 2027 ne-20% ngoJulayi 2028, ngaphandle kokuba kukho umyalelo wothungelwano lobushushu (Energieeffizienzgesetz, icandelo 11). Kwaye amaziko edatha akhula ngokukhawuleza: i-IEA iqikelela ukuba basebenzisa malunga ne-415 TWh yombane ngo-2024, malunga ne-1.5% ye-umbane wehlabathi, beqhuba ukuya kuthi ga kwi-945 TWh ngo-2030 (IEA, Energy and AI, 2025). Ininzi yale mandla embane iphela njengeqondo lobushushu eliphantsi.
EDenmark, eFinland naseSweden ukufudumeza kwephondo kubonelela ngenxalenye enkulu yentengiso yobushushu, nto leyo ibangela ukuba baqhube ukusetyenziswa kobushushu obulahlekileyo (Werner, 2017). Ezinye iindawo inxalenye elahlekile ihlala iyinethiwekhi, hayi ubushushu.
Ixabiso
Ukubuyiswa kwe-waste-heat akuvelisi umbane, ngoko ke inqanaba eliqhelekileyo lendawo (uphahla lwelanga $0.19 nge-kWh kwi- Imodeli yomgca we-Fan, ngaphakathi kwexesha leLazard ngoJuni 2026 $0.09 to $0.20 yelanga lorhwebo lwesilingi) isebenza kuphela kwimeko ezincinci zeqondo lobushushu oluphezulu ezivelisa umbane. Ubushushu, umncinane yibhoyile yegesi. Ukusetyenziswa kwamanani ajikelezayo afanayo Iphepha lokugcina ubushushu (igesi yentengiso ethe tyaba kwi-€35 ngeMWh, i-carbon kwi-€70 ngetoni, ibhoyile ye-90%), 5 ukuya kwi-6 ye-eurocents nge-kWh.
Ubushushu okuvela kumenzi wobushushu obuphantsi oludlula kwipompo enkulu yobushushu ibiza umbane ohlukaniswe yi-COP, kunye nezixhobo ezisasazwayo ngaphezulu kobushushu obunika. Published costs for large heat pumps and connections vary widely by site, so we show the range as a calculation (20 years, 7% real discount rate, COP 3, pipes and connection not included):
| Ixabiso elifakwe kwipompo yobushushu ngekW nganye | Electricity €50 per MWh, 3,000 hours a year | Umbane €50, 6,000 iiyure | Umbane €100, 3,000 iiyure | Electricity €100, 6,000 hours |
|---|---|---|---|---|
| €500 | 3.2 c | 2.4 c | 4.9 c | 4.1 c |
| €1,000 | 4.8 c | 3.2 c | 6.5 c | 4.9 c |
| €1,500 | 6.4 c | 4.0 c | 8.1 c | 5.7 c |
Iisenti ze-euro nge-kWh nganye yobushushu. Ubalo lwethu: iindleko zezixhobo × 0.0944 ÷ iiyure + ixabiso le-elektrikhi ÷ 3.
Ubushushu obubuyiselweyo buhlala bu konkura negesi xa ipompo yobushushu isebenza iiyure ezininzi ngonyaka kwaye umboneleli ukwindawo ecaleni kwenethiwekhi. Iindawo zayo ezibuthathaka ziipayipi (unxibelelwano olutsha lweekhilomitha ezimbalwa luya kubiza ngaphezulu kunepompo yobushushu) kunye nomngcipheko wokuba umthombo uphele. Ukusetyenziswa ngokuthe ngqo kweqondo lobushushu elishushu leshishini, ngaphandle koxinzelelo lokufudumeza ngaphaya koko, kuqhelekileyo ukuba lixabiso eliphantsi kakhulu lobushushu olunokuthengiswa ngumjelo.
Ukwenza umbane ukusuka kubushushu obulahlekileyo buhlukile: iyunithi ye-ORC ikhupha kuphela apho ubushushu bushushu, buhlala kwaye bukhululekile, yaye nalapho imveliso yayo incinane xa kuthelekiswa nobushushu obuya ngaphakathi.
apho ingaphumelela khona, nalapho ingaphumelelanga
Inokufumana:
- Iidolophu ezineenethiwekhi zombane ezikufutshane neendawo zokuqokelela idatha, imisebenzi yokuhambisa amanzi, iinkqubo zemetro, iivenkile ezinkulu kunye neefektri.
- Iindawo zokutyela zeshishini, apho ubushushu obulahlekileyo bemveliso enye buyinkqubo yokushisa kwemveliso enye.
- Iindawo ezintsha zokugcina idatha ezidweliswe ukusukela ekuqaleni ukunika amanzi ashushu, ngakumbi ngobushushu obucocekileyo kwi-40 ukuya kwi-60 °C.
- Izindlu eziphezulu zeqondo lobushushu (isinyithi, iglasi, intsimbi, iikhemikhali), apho ukutyibilika ngaphezu kwe-250 °C kungaqhuba iORC okanye umphunga weturbini wombane, okanye ukuqala izinto zokufudumeza.
- Ubushushu bezinto eziphilayo, ehlala ikhona, ikwindawo ephakathi kwemijikelo yemimandla emikhulu kwaye ifumaneka ngexesha lobusika.
Akukho nto iphumelelayo:
- Iziqhamo ezikude ezingakhoyo kumsebenzisi wobushushu okwindawo ekufuphi: isiseko sedatha yelizwe elinobungozi okanye isityalo esikhuselekileyo.
- Ukuguqula ubushushu obuphantsi beqondo lokushisa lube lumbane. Kwi-30 ukuya kwi-60 °C iCarnot ceiling yipesenti embalwa; akukho sixhobo sitshintshayo eso.
- Iindawo ezingabakho nendawo yombane, de kube umntu eyenza enye. Uthungelwano, hayi ubushushu, luhlala lube yimali ethe ngqo.
- Isizathu sokugcina inkqubo elahlekile. Ukusebenza kakuhle kukuqala.
Izinto eziqinisekisiweyo, ezinokwenzekayo
Iqinisekisiwe: iCarnot imida kwiqondo lobushushu ukuya kumandla kunye neepompo zobushushu; ukubuyiswa kweqondo lobushushu olukhulu ukusuka kwiziko ledatha kunye nezinto eziphilayo ukuya kwinqanaba lokufudumeza eHelsinki, Odense naseStockholm; amajelo okutya okushushu kweshishini lonke eDenmark naseSweden; iiyunithi zeORC zokubuyisela amandla egesi ukusuka kwifuthe elishushu leshishini.
Ingalindelekanga: iinkalo ezinkulu zedatha eYuropu zinika ubushushu obusetyenziswayo, zixhaswe zimithetho njengeJamani; amanethiwekhi aphantsi kobushushu athatha ngaphezu kobushushu obuphantsi; iiseva ezipholileyo eziliquid zinika amanzi angama-50 ukuya kuma-60 °C afuna umpompo wobushushu omncinci okanye awukho.
Izibalo: umbane obalulekileyo ngemali ukusuka kubushushu obungaphantsi kwe-80 °C; ukubuyisela ubushushu emizini engenamzobo wenethiwekhi; iipaneli ze-thermoelectric kwizinto eziqhelekileyo zokufudumeza iinkunkuma zihlawulisa ngokwazo.
Imibuzo yophando oluvulekileyo
- Ukwenza iimaphu. Kutheni, kubushushu obunjani nangokuninzi kangakanani ubushushu obulahlekileyo olungenayo, xa kuthelekiswa nobuninzi beqondo lokushisa ekufunekayo? Iimaphulo ezivulekileyo, zendawo zihlala zincinci.
- Iikontraki kunye nomngcipheko. Uphi ohlawulisa unxibelelwano, nowuphi othatha umngcipheko ukuba icebo livale?
- Iinethiwekhi eziphantsi kobushushu. Ukuguqula iinqanawa eziphezulu zobushushu kunye neendawo zokufudumeza ukuze zisebenze ngokupholileyo.
- Iipompo zobushushu obuphezulu ukunika umphunga kwi-120 ukuya kwi-200 °C yeshishini, ukusuka kubushushu obulahlekileyo kwi-60 ukuya kwi-100 °C.
- Indawo yokugcina yexesha lonyaka egcina ubushushu bendawo yokugcinwa kwedatha yonyaka omtsha.
- Imisebenzi eqikelelwayo. Iinkcukacha zenyanga ezipapashiweyo malunga nobushushu obunikezelwa, umbane osetyenziswayo kunye neendleko zeprojekthi
Izinto ezifunekayo
Iipompo zobushushu kunye neendawo zokutshintshiselana ngobushushu zikhula. Iinkqubo ezintsha eziluncedo zikwindawo zokudibanisa izithuthi kubasebenzisi ngexabiso eliphantsi, kwiqondo lobushushu eliphezulu lokufudumeza ipompo, kunye nolawulo. Imodeli esebenza kufuneka inikezele ubushushu obulinganiselweyo kumsebenzisi osebenzayo.
| Inkqubo | Umsebenzi | Uxanduva | Ixabiso elipheleleyo | Ixesha |
|---|---|---|---|---|
| 1. Uvavanyo lobushushu | Uvavanyo lokuhamba kunye nobushushu bemijelo yezinto ezilahlekileyo zendalo kwiiveki ezininzi ngezixhobo zokurekhoda; yenza iimaphu zabaxumi bobushushu ngaphakathi kwe-1 ukuya kwi-2 km | Ingaba kukho ubushushu obunenzuzo, kwiqondo lokushisa elisebenzayo, elihle ngokwaneleyo kumsebenzisi? | $5k to $20k | 1 ukuya kwiinyanga ezi-3 |
| 2. Umbonisi webench | I-10 ukuya kwi-50 kW yokutshintsha ubushushu kunye nepompo yobushushu kumsitho obonakalayo, ngemitha yobushushu nombane | I-COP eqikelelwayo, ukubola nokunyamezela kumgangatho olungileyo | $30k to $150k | 6 ukuya kwiinyanga ezili-12 |
| 3. Uqhagamshelwano loqhubi | Uqhagamshelwano kwisakhiwo okanye kumjelo omncinci, unyaka wedatha, ikontraki yonikezelo lobushushu | Ixabiso elipheleleyo nge-kWh nganye yobushushu kunye nemodeli yekontraki | $0.3M to $2M | 12 ukuya kwiinyanga ezili-24 |
abafuna
- Abanjiniyela be-heating yendawo nabaqhubi benkqubela phambili.
- Iinkqubo zokuhambisa ubushushu, ngakumbi kwiinjini ezinkulu kunye nezinga eliphezulu lobushushu.
- Iindawo zokugcina idatha kunye nabaphathi bezixhobo zeshishini abazimisele ukudibana kwiqondo lobushushu kunye nedatha yokuhamba.
- Abacwangcisi bezixeko kunye nabaqulunqi be-GIS ukumisela amacebo nabasebenzisi.
- Abagwebi nabaphandi bezoqoqosho ukuba bacwangcise ikontraki yobushushu edibanisa umngcipheko ngokuchanekileyo.
- Inkqubo yobunjineli yokutywina, ukubola nokucoca izitshintshi zeqondo lobushushu kwimijelo emanzi njengeendawo ezilahlekileyo kunye negesi ye-flue.
Unayo imbono engcono?
Abathile abaxhasi beFoundation banokuba nabaqhagamshelana nabo abanokuva ilizwi elinamandla lengqondo. Ukubekwa, imbono kufuneka ibe isebenza, imodeli yobomi bokwenyani eyenza amandla; kwi-idea yokubuyisela ubushushu, oko kuthetha imodeli enikezela ngobushushu obulinganiselweyo okanye umbane, kunye nemveliso yayo kunye nokusetyenziswa kwayo kweenkqubo zezixhobo, ezingasathethi ke. Iimbono zephepha zithandeka kakhulu: ukuba ifizikhi kunye namaxabiso aqinile, sinokuzipapasha apha kwiwebhusayithi. kodwa ukunyusa ikapitali ngaphandle kwemodeli esebenza kakuhle kunzima kakhulu, kwaye akukho nto apha inokuba yithemba lokuxhaswa, ukuphinda kwenziwe okanye ukunikezelwa.
Thumela imbono yakho nge ifomu yonikezelo nengxaki eyenzayo, uvavanyo lwefizikhi, ixabiso eliphakathi kwi-kWh nganye, kunye novavanyo olukhawulezayo olunokuthi luqinisekise ukuba ayichanekanga. Ukuba unemodeli esebenza kakuhle, dibanisa imveliso yayo eqikelelwayo kunye nendlela oyiqikelela ngayo. Iphepha izinto ezivelisa amandla lithelekiswa nalo namanye amayeza asetyenziswayo kwi-radar yembono.
IiNkqubo
- Forman, C., Muritala, I.K., Pardemann, R. noMeyer, B. (2016). Ukuqikelela uxinzelelo lwesinyithi esilahlekileyo. IiNkcazo zeNkqubo yoKhuseleko lweNkqubo yeNkqubo 57, 1568-1579.
- U-Helen (2018). Ipompo entsha yobushushu iya kukhiwa kwakhona eHelsinki; Wikipedia, Umbane eFinland.
- Injongo (2020). Isixeko saseOdense: ukubuyisela ubushushu.
- Iindawo zokugcina idatha eStockholm. Iwebhusayithi yenkqubo.
- Wahlroos, M., Pärssinen, M., Rinne, S., Syri, S. noManner, J. (2018). Imbono yexesha elizayo malunga nokusebenziseka kobushushu obulahlekileyo: iimeko zezixeko zokugcina idatha eMntla weYuropu. IiNkcazo zeNkqubo yoKhuseleko lweNkqubo yeNkqubo 82, 1749-1764.
- Quoilin, S., Van Den Broek, M., Declaye, S., Dewallef, P. noLemort, V. (2013). Uvavanyo lwetekhnoloji-yoqoqosho lwenkqubo yeSikhumbuzo seRankine esiphilayo (ORC). IiNkcazo zeNkqubo yoKhuseleko lweNkqubo yeNkqubo 22, 168-186.
- Lund, H., Werner, S., Wiltshire, R. et al. (2014). 4th Generation District Heating (4GDH). Energy 68, 1-11.
- Werner, S. (2017). Uvavanyo lwamazwe ngamazwe lokufudumeza kunye nokupholisa Energy 137, 617-631.
- iJamani (2023). Energieeffizienzgesetz (EnEfG), icandelo 11: iindawo zokugcina idatha.
- IEA (2025). Umbane ne-AI.
- Lazard (Juni 2026). Ixabiso eliNciphisayo leNkqubo, uguqulelo 19.
- Local Solar System Isiseko. Imodeli evulekileyo yomgca we-fan wall: ixabiso lelanga elinomtsalane kwindlu yangasese liyi- $0.19 nge-kWh.
- I-Wikipedia. Amager Bakke: 157 ukuya kwi-247 MW yobushushu bendawo kunye ne-63 MW yegesi evela kutywala lwesixeko, enethambeka lokukhwela i-ski ecaleni kwesakhiwo.