Refers to the act of using or consuming goods, services, or resources. Often used in economic or business contexts, but can apply to general usage. Note that 需用 is distinct from the more common homophone 需要 (demand).
Electricity consumption peaks in summer.
The use of this product is increasing year by year.
consumables expense; supplies cost
Compound of 需 (need, demand) and 用 (use). The exact historical derivation is uncertain, but the kanji combination naturally conveys the meaning of 'use based on need'.