Although only a small amount of zinc is used to conserve the embodied energy of steel, an important life cycle consideration for galvanizing is the energy used to produce zinc metal. The Swedish Environmental Protection Agency has compared the relative energy requirements of the common base metals and found that, with the exception of iron (the basis of steel), zinc uses the lowest energy on both a per unit weight and per unit volume basis. The energy used in electrolytic zinc production is approximately 7% for mining and mineral processing; 89% for electrolysis and 4% for casting.
Energy use in primary (refined) production of various base metals in relation to weight and volume.
Energy use for iron/steel is set at one in both cases.