As we prepare to enter the 21st century we stand on the threshold of a power electronics revolution. The last 50 years have seen the growth of power conversion to the point at which today about 15% of the electric power produced undergoes some form of electronic conversion. However most of this occurs nt the ＇consumer end＇ of the supply chain from battery chargers to locomotives. Although HVDC transmission has exploited line-commutated power electronics for the past three decades, it is the 1990s which have witnessed the commissioning of self-commutated power electronics nt the transmission level. Developments in semiconductors ann their packaging technology will drive power electronics into distribution applications ns device efficiency min reliability increases whilst the cost of the switched megawatt falls. The key semiconductors enabling this predicted transition are reviewed and the anticipated demands of system builders on device suppliers discussed.