Around 25 per cent of the electrical energy consumed by the process industry are used for powering pumps and fans. By optimizing flow control, the consumption of electricity and operating costs can be reduced substantially, as can the environmental loading. This is the claim of Control Drive Sweden AB in Karlstad, Sweden. The Swedish company has developed a variable speed drive for equipment such as pumps and fans that reduces the energy requirement by 30-60 per cent, according to the manufacturer. The pay-off time for the investment is estimated to be 6-24 months.