Steelmakers fire up to swap centuries-old reliance on coal for electric arc furnaces

As Tata Steel and British Steel close their polluting blast furnaces, will Labour get behind the switch to more energy-efficient technology - and secure jobs?

The warning is to wait for the snap, crackle and pop" as three glowing electrodes are dropped into an electric arc furnace in Cardiff. What follows sounds like thunder and lightning. It is a human-induced storm in a massive, ceramic-lined cup, holding 140 tonnes of rapidly melting steel.

The plant, owned by Spain's Celsa, melts scrap steel using high-voltage electrical currents that generate the 1,600C needed to turn the metal to liquid. The glowing steel is then ready to be cast, twisted and crushed into the rods used to reinforce concrete.