Ko te kaha ko te tapeke o te hiko ka taea e te pākahiko rā te penapena, e inehia ana i roto i ngā kilowatt-haora (kWh). Ko te nuinga o ngā pākahiko rā o te kāinga he mea hanga kia "whakapūmau", ko te tikanga ka taea e koe te whakauru i ngā pākahiko maha ki tō pūnaha penapena-rā-me-te-kaha hei whiwhi kaha tāpiri.
Ahakoa e whakaatu ana te kaha ki a koe i te rahi o tō pākahiko, kāore e whakaatu ana i te nui o te hiko ka taea e te pākahiko te tuku i tētahi wā. Hei whiwhi i te pikitia katoa, me whakaaro anō hoki koe ki te whakatauranga mana o te pākahiko. Mō ngā pākahiko rā, ko te whakatauranga mana ko te nui o te hiko ka taea e te pākahiko te tuku i te wā kotahi. Ka inehia i roto i ngā kilowatt (kW).
He iti te hiko e tukuna ana e te pākahiko he nui te kaha, he iti hoki te mana (he nui hei whakahaere i ētahi taputapu nui) mō te wā roa. Ka taea e te pākahiko he iti te kaha, he nui hoki te mana te whakahaere i tō whare katoa, engari mō ngā haora torutoru noa iho.