近日,國海證券股份有限公司發布名(ming)為《熔鹽儲(chu)熱:長時(shi)儲(chu)能賽道的潛力路線》的最新研究(jiu)報告。
報告指出,長(chang)時(shi)(shi)儲(chu)能(neng)是(shi)未來新型電(dian)(dian)(dian)力系統的(de)(de)重(zhong)要方向。當前(qian)發(fa)電(dian)(dian)(dian)側電(dian)(dian)(dian)化學儲(chu)能(neng)時(shi)(shi)長(chang)大多在2小(xiao)時(shi)(shi)左右,可以一定程度上緩解棄電(dian)(dian)(dian)現(xian)象,但(dan)不能(neng)完全實現(xian)“削峰(feng)填谷”。采用長(chang)時(shi)(shi)儲(chu)能(neng)可以更好調節電(dian)(dian)(dian)力供需,同時(shi)(shi)可以更加充(chong)分利用峰(feng)谷電(dian)(dian)(dian)價提高利潤(run)。根據美(mei)國電(dian)(dian)(dian)力研(yan)究院(EPRI),持續放(fang)電(dian)(dian)(dian)時(shi)(shi)間(jian)為4小(xiao)時(shi)(shi)的(de)(de)儲(chu)能(neng)系統的(de)(de)獲得利潤(run)是(shi)持續放(fang)電(dian)(dian)(dian)時(shi)(shi)間(jian)20小(xiao)時(shi)(shi)的(de)(de)長(chang)時(shi)(shi)儲(chu)能(neng)系統的(de)(de)76%。
熔(rong)(rong)鹽(yan)(yan)儲(chu)能(neng)是長時儲(chu)能(neng)的一(yi)種技術路(lu)線,規模(mo)有(you)望實現跨越式增長。熔(rong)(rong)鹽(yan)(yan)儲(chu)熱(re)(re)(re)蓄熱(re)(re)(re)時采用智能(neng)互(hu)補系(xi)統將風電、光伏(fu)、夜間低谷電作為熔(rong)(rong)鹽(yan)(yan)電加(jia)熱(re)(re)(re)器(qi)的電源,通(tong)過熔(rong)(rong)鹽(yan)(yan)電加(jia)熱(re)(re)(re)器(qi)加(jia)熱(re)(re)(re)熔(rong)(rong)鹽(yan)(yan),儲(chu)存熱(re)(re)(re)量(liang);放熱(re)(re)(re)時在換熱(re)(re)(re)系(xi)統中高(gao)溫熔(rong)(rong)鹽(yan)(yan)與水進(jin)行換熱(re)(re)(re),釋(shi)放熱(re)(re)(re)量(liang)。熔(rong)(rong)鹽(yan)(yan)儲(chu)能(neng)可以(yi)根據能(neng)量(liang)需求自由調整輸出時間,敦煌百兆瓦熔(rong)(rong)鹽(yan)(yan)塔式光熱(re)(re)(re)電站的熔(rong)(rong)鹽(yan)(yan)儲(chu)熱(re)(re)(re)時間可以(yi)達到11個(ge)小時。
圖(tu):熔鹽儲熱原理(資(zi)料來源:中科儲能官網)
根(gen)據(ju)不(bu)完全統計,2022年招標/簽約/建設中的熔鹽儲熱項目達(da)16個【詳(xiang)見如下(xia)匯總(zong)表】,總(zong)裝機規模達(da)3074MW。
報告(gao)介(jie)紹了熔鹽儲能的幾大優勢:
①儲能(neng)(neng)規(gui)模(mo)大:熔(rong)鹽儲熱規(gui)模(mo)通常在幾十兆(zhao)瓦到幾百兆(zhao)瓦之間,例如(ru)甘(gan)肅省金昌市(shi)高溫熔(rong)鹽儲能(neng)(neng)綠色(se)調(diao)峰電站儲能(neng)(neng)規(gui)模(mo)達到600MW/3600MWh;
②儲能時(shi)間長:熔鹽儲能可(ke)以實現單日10小(xiao)時(shi)以上的儲熱能力,敦煌百兆(zhao)瓦熔鹽塔(ta)式光(guang)熱電站(zhan)的熔鹽儲熱時(shi)間可(ke)以達(da)到(dao)11個小(xiao)時(shi),遠遠高(gao)于當前(qian)2-4小(xiao)時(shi)的配(pei)儲比例要求;
③壽(shou)(shou)命長(chang):熔鹽(yan)儲熱項目(mu)壽(shou)(shou)命在(zai)25年左右;
④環保安全:不產生(sheng)污(wu)染(ran)排放。
同時,報告(gao)也指出(chu)了(le)熔鹽儲(chu)能技術的局限性:
①成(cheng)本(ben)較高(gao):已投運的(de)裝機110MW配10小時儲能(neng)(neng)的(de)新月(yue)沙丘(qiu)熔鹽塔(ta)項目的(de)總投資額(e)約(yue)(yue)8億美(mei)元(約(yue)(yue)合人(ren)民54億元),據此計算(suan)投資成(cheng)本(ben)在500萬/MWh左右,據《電(dian)化(hua)學與蓄熱(re)儲能(neng)(neng)技術(shu)在可再生能(neng)(neng)源領域的(de)應用》測算(suan),在不(bu)考慮能(neng)(neng)量損(sun)失(shi)的(de)情況(kuang)(kuang)下熔鹽儲熱(re)度電(dian)成(cheng)本(ben)約(yue)(yue)0.443元/kWh,則在50%轉化(hua)效率(lv)的(de)情況(kuang)(kuang)下度電(dian)成(cheng)本(ben)約(yue)(yue)0.886元/kWh。
②能量利用(yong)率較(jiao)(jiao)低:在換(huan)熱系統中高(gao)溫熔(rong)鹽與水換(huan)熱,產生水蒸(zheng)汽,驅動渦輪機工作階段能量浪費較(jiao)(jiao)多(duo),效率較(jiao)(jiao)低。
③熔鹽(yan)具有腐蝕性(xing):熔鹽(yan)中含有的氯化鹽(yan)、碳酸鹽(yan)、硝(xiao)酸鹽(yan)對熔融罐、管(guan)道等設備具有一定腐蝕作(zuo)用。
報告(gao)整理了目(mu)前熔鹽儲熱的4種典型應用場(chang)景:
1)光熱發(fa)電:二元鹽(60%硝(xiao)酸鈉+40%硝(xiao)酸鉀)是(shi)目(mu)前多數光熱電站(zhan)選用的傳儲(chu)熱工質,其熔(rong)點(dian)為(wei)(wei)220℃,最高工作溫(wen)度可達600℃。2009年(nian)3月成功運行的西班(ban)牙安(an)達索爾槽式光熱發(fa)電站(zhan)配(pei)置(zhi)了熔(rong)鹽儲(chu)熱系統(tong),成為(wei)(wei)全(quan)球首個(ge)商業化聚光太陽能電站(zhan)。截至(zhi)2021年(nian)末,熔(rong)巖儲(chu)能在全(quan)球儲(chu)能市場中累(lei)計規模占(zhan)比1.6%,在國內累(lei)計規模占(zhan)比1.2%。
2)清潔供熱(re)(re):借助峰谷電(dian)加熱(re)(re)熔(rong)(rong)鹽(yan)(yan)蓄熱(re)(re)集(ji)中供暖的“煤改電(dian)”技術(shu)實施系(xi)統大致有熔(rong)(rong)鹽(yan)(yan)電(dian)加熱(re)(re)器、低溫、高溫熔(rong)(rong)鹽(yan)(yan)罐、混(hun)合(he)熔(rong)(rong)鹽(yan)(yan)、熔(rong)(rong)鹽(yan)(yan)泵、熔(rong)(rong)鹽(yan)(yan)-水換(huan)熱(re)(re)器等設備(bei),對(dui)面積超過10000m2的建筑更為(wei)適用,整(zheng)個系(xi)統的投資(zi)成本大約在150元/m2,供暖運行成本根(gen)據峰谷電(dian)價不(bu)同在13~18元/m2,具有良好的經濟性能(neng)。
3)工業(ye)蒸汽(qi):熔(rong)(rong)鹽蓄(xu)熱(re)(re)(re)技術不僅可(ke)(ke)以(yi)(yi)使用(yong)谷電(dian),還可(ke)(ke)以(yi)(yi)大(da)量使用(yong)工業(ye)余(yu)熱(re)(re)(re)、太陽能集(ji)熱(re)(re)(re)或直接利用(yong)火電(dian)廠生產的(de)蒸汽(qi)等,通(tong)過這(zhe)些熱(re)(re)(re)源來(lai)直接加熱(re)(re)(re)熔(rong)(rong)鹽,便可(ke)(ke)以(yi)(yi)實現相(xiang)比電(dian)熱(re)(re)(re)轉換更高的(de)能源轉換效率。而在(zai)輸出端,熔(rong)(rong)鹽蓄(xu)熱(re)(re)(re)系統除了供(gong)暖,還可(ke)(ke)以(yi)(yi)服(fu)務需求更加多樣(yang)化的(de)工業(ye)蒸汽(qi)市場(chang)。
4)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)靈活(huo)性(xing)改(gai)造:火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)靈活(huo)性(xing)改(gai)造的(de)主要目標是改(gai)善(shan)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)的(de)最小出力限制,擴大(da)機(ji)組(zu)(zu)(zu)(zu)出力調節的(de)幅度(du),減小熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)聯(lian)產組(zu)(zu)(zu)(zu)合(he)中(zhong)發電(dian)(dian)(dian)(dian)(dian)(dian)對發熱(re)(re)(re)的(de)配比(bi)(bi),即(ji)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)解耦(ou)。目前實(shi)現(xian)發電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)熱(re)(re)(re)電(dian)(dian)(dian)(dian)(dian)(dian)解耦(ou)的(de)技術路線較多,熔鹽(yan)儲(chu)能(neng)技術是其中(zhong)重要方(fang)法之一,其可(ke)與(yu)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)熱(re)(re)(re)力系統參數相匹配,顯著(zhu)改(gai)善(shan)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)供熱(re)(re)(re)調峰(feng)(feng)能(neng)力。蒸汽加熱(re)(re)(re)熔鹽(yan)儲(chu)能(neng)的(de)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)調峰(feng)(feng)技術與(yu)現(xian)有的(de)火(huo)電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)組(zu)(zu)(zu)(zu)調峰(feng)(feng)技術相比(bi)(bi),具有能(neng)耗低、機(ji)組(zu)(zu)(zu)(zu)運行更節能(neng)可(ke)靠,改(gai)造成本低等優點。
此(ci)外,報告給出如下投資建議:行業方(fang)(fang)面(mian),隨(sui)著電力系統對調節能(neng)力需(xu)求提升、新能(neng)源開發消納規模不斷加(jia)大(da),長時儲能(neng)建設進度有望加(jia)速(su)。維持行業“推(tui)薦”評級。個股方(fang)(fang)面(mian),建議關注首(shou)航高(gao)科、西子(zi)潔能(neng)、上(shang)海(hai)電氣、安彩(cai)高(gao)科、洛陽玻(bo)璃、中能(neng)科技、魯陽節能(neng)等。
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