Uhlelo lokugcina amandla (ESS), njengoba igama lisho, uhlelo olusetshenziselwa ukugcina amandla, olungabhekisela ekuguqulweni kwamandla kagesi ohlelweni lwamandla abe uhlobo oluthile lwedivayisi olungagcina amandla ukuze aguqulwe abe amandla kagesi uma kudingeka. Ukunikezwa kwamandla okungenakuguqulwa (UPS) kungumthombo wamandla okufaka ohlinzeka ngamandla aphuthumayo emthwalweni lapho ukunikezwa kwamandla okuyinhloko kwemishini kagesi kwehluleka, okusetshenziselwa ukuvikela imishini enezidingo eziphezulu zokuzinza kokunikezwa kwamandla kagesi. Uma kwenzeka ukwehluleka, inikeza amandla e-AC asekelayo emishinini yomthwalo kagesi ngaphandle kokuphazamiseka ukuze kugcinwe ukusebenza okuvamile kwemishini kagesi. Lokhu kwehluleka kufaka phakathi ukucima kukagesi, ukungasebenzi kahle kwamandla kagesi, ukuphazamiseka noma ukukhuphuka kwamandla kagesi.

I-ESS iyonke ihlukile ohlelweni lwe-UPS.

Okokuqala, ukusetshenziswa kohlelo lwe-UPS kuwuhlelo oluphuthumayo oluvela lapho ugesi oyinhloko uphela. Ngaphezu kwesimo esiphuthumayo, ugesi ku-ESS usetshenziselwa umthwalo ophezulu ezimweni eziningi, futhi usetshenziselwa "ukusika okuphezulu kanye nokugcwalisa isigodi" ngezinye izinhlobo zamandla, njengamandla enuzi, amandla omoya, amandla elanga, njll. Amandla angadluliselwa ukuze kuncishiswe izindleko, noma ukusiza leyo mithombo yamandla engapheli ukuthi ithunyelwe ngaphandle kancane kancane. okwesibili, i-UPS, njengohlelo oluphuthumayo, imvamisa iwukugcina ukuzinza kwemishini ethile ebalulekile, ukuze ibe nesikhathi sokuvala ngokujwayelekile noma kuze kube yilapho ugesi ophuthumayo uvuliwe, ngakho-ke isikhathi ngokuvamile asiside kakhulu, singaba yimizuzu eyishumi noma ngisho nemizuzu embalwa, bese sivula ugesi ophuthumayo, ugesi ophuthumayo ungavela ohlelweni lwe-ESS noma kwezinye izinjini zogesi ezilindile. Okokugcina, uhlelo lwe-UPS lunemishini yokugcina ugesi, ezinye izinhlelo ze-UPS zisebenzisa uhlelo lwe-flywheel ukugcina ugesi, ezinye izinhlelo ze-UPS zisebenzisa izinhlelo zebhethri ukugcina ugesi, kodwa futhi nangesikhathi sokuthula ukushaja uhlelo lokugcina ugesi, lapho uhlelo oluyinhloko lwamandla luhlangabezana nokwehluleka, i-UPS iqala ukuhlinzeka ngogesi ongaphazanyiswa.