In the 200 years since the links between electricity and magnetism were discovered and formulated by Oersted, Ampère and Faraday, society has become dependent on electromagnetic systems to deliver electrical energy to end-users. The majority of the electrical energy produced - about 25,000 Terawatt hours in 2016 – is created by transforming mechanical to electrical energy through turbo- and hydro-generators and wind turbines. Every Watt hour of energy generated also passes through several transformers (electromagnetic systems) on its way to the end-user.