Aluminum is the most energy-intensive major industrial metal: smelting one tonne consumes roughly 14 MWh of electricity. China, which accounts for nearly 60% of global output, established a self-imposed statutory cap of 45 million tonnes of annual smelting capacity in 2017 and has now collided with it: national production has crossed 43 million tonnes, leaving virtually zero room for further expansion. For the first time in two decades, the global supply engine of primary aluminum has been shut down by political mandate rather than market forces.
In theory, Western producers should step in to fill the gap, but a second structural constraint prevents this: power availability. An aluminum smelter is essentially a dedicated power plant with an attached casthouse, requiring long-term, low-cost power contracts secured for decades. Today, AI data centers, transport electrification, and domestic re-industrialization are outbidding industrial users for available megawatts, with grid interconnection queues stretching years. The United States is smelting its lowest volume of primary aluminum since the 1950s, while Europe curtailed ~2 million tonnes of capacity during the 2021-2022 energy crisis, most of which will never restart. The first planned new US smelter in over 40 years remains stalled awaiting a power purchase agreement, highlighting where the true bottleneck lies.