Plant & Works Engineering June 2022

I ndustrial compressed air applications consume 11.71 TWh of electricity per year, accounting for as much as ten per cent of all the energy consumed by industry. 1 As energy prices continue to rise at an unprecedented rate, many operators are seeking innovative ways to cut their electricity consumption from compressed air. At the same time, sustainability has become one of the leading factors for decision-makers when selecting a new air compressor. In addition to cost and performance considerations, determining a compressor’s impact on the environment is now a major consideration in the purchasing decision. Traditionally, compressors have used fixed speed motors, which means they run at a consistent speed, and produce a fixed amount of compressed air per minute, regardless of air demand. In most scenarios, it is unlikely that the exact amount of compressed air generated will be required. This means the compressor can potentially be creating compressed air that ends up being wasted. In addition, fixed speed compressors run unloaded, as the stress of an engine start-up would put pressure on the motor. This can be a waste of energy as the machine is running without producing any compressed air. In contrast, variable speed compressors have the ability to start and stop under full system pressure. They use an intelligent drive system to constantly alter the speed of the motor and to match the air generated to the required process demand. This allows for the required high speeds for compression, while generating sufficient flow to meet plant requirements, hence minimising power consumption. This technology can potentially have a big impact on businesses productivity, efficiency and sustainability levels. When compared Process, Controls & Plant Focus on: Compressed Air 24 | Plant & Works Engineering www.pwemag.co.uk June 2022 Lowering energy consumption with variable speed compressor technology Colin Mander, Business Line Director at CompAir, discusses the role that variable speed compressors can play in helping businesses to reduce their electricity consumption. Indeed, every kWh in electricity saved now, will contribute to even greater savings with the current and unprecedented increase in electrical costs.