Aluminium prices on Thursday rose back above the key $3,000-a-tonne level as investors bet that China’s power shortages could be aggravated by damage to dams and the grid by the recent earthquake, leading to lower supplies.

Aluminium is the most power-intensive among base metals and electricity accounts for about a third of its production costs. China is the world’s largest producer of the metal, accounting for about 25 per cent of global output, according to Deutsche Bank.