Household DC networks: State of the art and future prospects

Over a century ago George Westinghouse, with the support of Nikola Tesla, defeated Thomas Edison in the ‘War of Currents’, thereby successfully establishing alternating current (AC) as the primary mode of electricity transmission and distribution. Large power plants such as coal, nuclear and hydro, are often located far from consumption centres. With transformers, the voltage level of AC power is easily increased to very high voltages, which is preferable for long distance transmission, before being stepped down again to levels that are safe for consumers to use. Today, however, there is a revival of direct current (DC) for high voltage transmission, particularly for long distances, and integrating largescale renewables such as hydro and wind parks.