Drives & Controls Magazine September 2023

28 n ENERGY EFFICIENCY September 2023 Practical steps to sustainable automation Cutting energy consumption is at the top of most companies’agendas: and not just because of cost. Listed companies must disclose their energy use, carbon footprint and greenhouse gas emissions in their financial reporting. The UK is also committed to reducing energy demand by at least 15% to support our legally binding net-zero commitments. This will require every business to understand and plan the balance between economics and environmental aspects, to secure a long-term future for everyone. Reducing energy usage is doubly challenging in a period of rapid growth in production output. We want more from our production lines for less. This involves taking measures at all levels, starting with planning the latest sustainable energy sources such as efficient heat and power plants that recover waste heat from processes such as compressed air production, and recycling this energy to reduce usage in other areas. Selling recovered energy to other consumers in the area is an option. At the level of individual production lines and machines, ensuring that new equipment is specified with energy consumption in mind is high on the agenda: monitoring, mapping, and optimising the distribution of continuous and peak requirements. These elements ensure that the foundations are in place for continuous improvement. Close collaboration with suppliers helps to optimise new machinery and production lines by incorporating the latest energy-saving technologies. And where immediate capital investment is not practical, the energy performance of legacy machinery can be improved through small practical actions, supported by a knowledgeable operations team. Within Festo, we have already taken steps to improve our own environmental performance. We have quantified energy usage, and prioritised measures to reduce, change and offset. We’ve also set ourselves clear goals. By the end of 2023, all of our sites and buildings in Germany, as well as our production and logistics sites around the world, will be CO2neutral, and our remaining locations will follow by 2026 at the latest. We have also trained our staff in the essential part they play in our energy consumption and therefore our carbon usage and environmental impact. Compressed air Having set our own house in order, we want to help our customers choose the best technologies and components and use best practice in design, build and operations to reduce their energy consumption and carbon usage. This is particularly important with compressed air systems, which are notorious for over-sizing and poor maintenance – both of which can be solved. Fig. 1 gives examples of some simple measures that can be taken. However, this is a generalist approach, and the biggest gains will be made at the design stage, by conducting a critical design analysis considering energy as well as performance and Capex cost. For existing installations, specialist analysis, support and advice can be obtained using ISO/DIS 11011 accredited audits. Low-cost or free audible leak detection audits can seem an attractive option, but often lead to the same faults being identified with nothing being done about them. An audit in isolation is not enough. It needs to be integrated with training and topdown commitment and support. The returns on time invested are impressive, both on new machine builds and existing plant audits. For new pneumatic installations, typically 80% of the lifetime costs are in the energy consumed (the rest is split between the purchase cost and maintenance). So, whether it be at zero or a small added cost, optimisation can have a massive effect on the TCO. A recent audit of a customer’s plant identified tens of thousands of pounds of savings. The initial investment was only a fraction of the cost and provided payback in a few months. Furthermore, even larger savings were identified that could be incorporated through a review of the compressor and distribution network, installation and controls. n A free webinar giving more information on how to optimise machinery design to reduce compressed air consumption and thus improve the total cost of ownership is available online. It demonstrates the latest techniques and tools available to optimise designs for energy consumption, cost, and performance. Reducing energy use is essential to most businesses, and listed companies have to publish their “green” achievements. There are many ways to reduce energy consumption. Steve Sands, technical consultant at Festo GB, examines some of them, looking especially at compressed air installations. Fig 1: Ten top tips for lowering compressed air consumption