Nickel ni ibikoresho by'ingenzi mu gukora ibyuma bitangiza ibyuma kandi bingana na 50% by'igiciro cyose. Vuba aha…
Icyuma cya karuboni ni icyuma cya karuboni n'icyuma gifite uburemere bwa karuboni bugera kuri 2.1%. Ubwiyongere bw'ubunini bwa karuboni byongera ubukana n'imbaraga by'icyuma, ariko bigabanya ubushobozi bwo kugenda neza. Icyuma cya karuboni gifite ubushobozi bwiza mu bijyanye n'ubukana n'imbaraga kandi gihendutse ugereranyije n'ibindi byuma.
Imiyoboro y'icyuma cya karuboni idakora neza ikoreshwa cyane mu nganda za kirimbuzi, mu kohereza gaze, mu bucuruzi bwa peteroli, mu bwubatsi bw'amato, mu byuma bishyushya n'izindi nganda, ifite ubushobozi bwo kurwanya ingese nyinshi n'ubushobozi bwiza bwo gukora.