Ultra-high-voltage electricity transmission (UHV electricity transmission) has been used in China since 2009 to transmit both alternating current (AC) and direct current (DC) electricity over long distances separating China's energy resources and consumers. Expansion of both AC and DC capacity continues in order to match generation to consumption demands while minimizing transmission losses. Decarbonization improvements will result from the replacement of lower efficiency generation, located near the coast, by more modern high-efficiency generation with less pollution near the energy resources.