The author submits that the highest possible efficiency of an electrical undertaking can only be attained by studying all the factors which at present militate against a low selling price per unit. The low average power factor existing on many undertakings could be raised, and consumers should be encouraged to improve their power factor by the establishment of a principle of granting a rebate for a high power factor.It is considered that a kVA charge plus a kWh charge is more equitable to power suppliers and consumers than a pure kWh basis of charge, and, now that the 1922 Act provides for a kVA basis at the option of any supplier, it is felt that a change should be made as soon as possible.Consumers should be educated and advice given gratuitously by a supply department so that the most suitable plant may be installed in order to obtain the highest all-round efficiency. By increasing the average power factor on any a.c. system the capital expenditure on generating, transforming and distribution plant, and also energy losses, can be considerably reduced to the advantage of both supplier and consumer.Power-factor-correcting apparatus is now on the market and is suitable for all requirements. Each type should be considered on its merits for every installation. The selling price of electrical energy per unit should be reduced on an improvement of power factor, and increased where it falls below a pre-determined standard.