Metal halide and high pressure sodium (SON) discharge lamps are predominantly used in larger buildings and complexes, such as shopping malls, factories, halls, conference centres etc.etc.. In common with the majority of discharge lamp systems both types require a ballast in operation, but their fundamental characteristics mean that conventional HF and HFR ballast control methodologies are unsuitable. The significant performance benefits and energy savings that can currently be achieved with low pressure mercury discharge fluorescent lamps are therefore not obtainable at the moment for lighting in industrial aplications, larger buildings and complexes. The successful application of high frequency ballast techniques to metal halide and sodium vapour lamps has not been accomplished before at a cost competitive with conventional ballast and control gear systems. In order to be commercially viable the developed systems must be equivalent in size and- cost to existing conventional ballast systems. These constraints place severe demands on the inductor technologies and design protocols developed. It is the purpose of this Exploratory award proposal to assess the feasibility of developing practicable HF ballast designs and lighting control and energy management systems capable of handling the power requirements and control characteristics of both Metal Halide and high pressure sodium discharge lamps - with due regard to the limiting factors of weight. size and cost for use in buildings. Energy savings for fluorescent application of over 30% have already been achieved but in considering the technically more difficult ballast requirement and control of Metal Halide and SON lamps even a 15%-25% overall reduction in energy requirement would represent an annual reduction in European demand in excess of 1,000 GWh of electricity - representing a cost saving in excess of 30 million ECU - 40 million ECU per annum.