I loko o kahi kaapuni AC, aia ʻelua ʻano mana uila i hoʻolako ʻia i ka ukana mai ka lako mana: ʻo kekahi ka mana hana a ʻo kekahi ka mana reactive. Ke ukana resistive ka ukana, ʻo ka mana i hoʻopau ʻia he mana hana, ke ukana capacitive a inductive paha ka ukana, ʻo ka hoʻopau ʻana he mana reactive. ʻO ka voltage mana hana a me ke au i ka pae like (ʻo ka mana AC ka ʻokoʻa ma waena o ka mana hana a me ka mana reactive), ke ʻoi aku ka voltage ma mua o ke au, ʻo ia ka mana reactive inductive; ke ʻoi aku ka au ma mua o ke voltage, ʻo ia ka mana reactive capacitive.

ʻO ka mana hana ka mana uila e pono ai e mālama i ka hana maʻamau o nā lako uila, ʻo ia hoʻi, ka hoʻololi ʻana o ka ikehu uila i nā ʻano ikehu ʻē aʻe (ikehu mechanical, ikehu māmā, wela) o ka mana uila. No ka laʻana: 5.5 kilowatts o ka motika uila he 5.5 kilowatts o ka ikehu uila i hoʻololi ʻia i ikehu mechanical, e hoʻokele ana i ka pamu e pamu i ka wai a i ʻole ka mīkini wili palaoa; e hoʻololi ʻia nā lako kukui like ʻole i ikehu māmā, no ka poʻe e noho a hana i ke kukui.

ʻOi aku ka mana reactive; ʻo ia ka mana uila i hoʻohana ʻia no ka hoʻololi ʻana o nā kahua uila a me nā kahua magnetic i loko o kahi kaapuni a e hoʻokumu a mālama i ke kahua magnetic i nā lako uila. ʻAʻole ia e hana ma waho, akā ua hoʻololi ʻia i nā ʻano ikehu ʻē aʻe. ʻO kēlā me kēia mea uila me kahi coil electromagnetic e hoʻopau i ka mana reactive e hoʻokumu i kahi kahua magnetic. No ka laʻana, ʻoi aku ka nui o ka mana hana ma mua o 40 watts o kahi kukui fluorescent 40-watt (pono pū ka ballast e hoʻopau i kahi hapa o ka mana hana) e hoʻopuka i ka mālamalama, akā pono pū kekahi ma kahi o 80 mana reactive no ka coil ballast e hoʻokumu i kahi kahua magnetic alternating. No ka mea, ʻaʻole ia e hana i ka hana waho, e kapa wale ʻia ʻo "reactive".