Researchers from the Canadian University of Waterloo have designed a new type of electricity distribution system which offers both AC and DC systems to power homes, industries and electric vehicles. Existing power networks usually only transmit alternating currents. In such networks, the energy produced by power stations is converted to high voltages using transformers to limit power losses related to long-distance transmission to a minimum. The voltage is then reduced in the distribution networks using transformers. Electricity from local substations is, therefore, also AC, and all DC power electronic devices in homes and companies must include AC-DC converters.