Approximately 5% of global iron production is used for cast iron products, which are commonly used for engine blocks, machinery, fences, buildings and construction. Cast iron is produced mainly by remelting scrap of iron in cupola furnaces and pouring the molten metal into moulds. The total energy use for the iron melting is 5–10 GJ/t-iron. The most efficient cupolas use 3 GJ of coke per tonne of cast iron. The relevance of cast iron in energy terms on a global basis is limited at about 250 PJ coke, equal to 2% of total global coke production (IEA, 2007). However, upgrading old and inefficient cupola furnaces in small scale operations collectively offers a meaningful potential, particularly for India and China.