Outside track: Driving up energy-efficiency

Outside Track: ERJ reports on news, views & developments from across the wider process and manufacturing industries worldwide:

ERJ: To what extent are tire & rubber product manufacturers up-to-speed when it comes to awareness of, and investment in, energy-efficiency?

FB: The leading global tire companies have made formal commitments during their latest investor days to first meet their net-zero targets by 2030 and to achieve full sustainability for their processes and products by 2050. Increasing energy efficiency is an integral part of this commitment and it is clear that all players in the supply-chain must contribute to the overall effort, otherwise you will inevitably no longer be a supplier.

ERJ: How have levels of awareness and capex developed over the past 2-3 years?

FB: Rubber and plastic applications are already at a good level. However, the environmental sensitivity of this sector for both public opinion and the media, means that this industry must be one step ahead of the rest. This explains the huge investments that have been made over the past two decades.

In April 2024, the Energy Efficiency Movement published the results of a global survey that gathered responses from 1,282 business leaders across many countries.

The survey revealed that 99% of businesses are already investing in, or are planning to invest in, making their energy usage more efficient. Notably, the number of businesses actively investing in energy efficiency has increased by 7% from two years ago.

The report, entitled “From Insight to Implementation: Business Perspectives on Energy Efficiency Investments” found that of the businesses investing, or planning to, 41% cite the next 12 months as the timeframe for making these improvements.

Moving data to the cloud (71%) is the most common energy efficiency measure currently invested in by businesses, followed by performing energy efficiency audits (69%), and improving energy efficiency of cooling systems (64%).

ERJ: Where are the bottlenecks in adopting the latest energy-efficient motors and related systems?

FB: The beauty of energy-efficient motors is that they generally offer a drop-in replacement for existing inefficient motors. That means an upgrade can be made with minimal downtime or disruption. However, it is important to remember that advanced motors must be installed as part of a package with a variable speed drive (VSD) – the drive is essential for their operation.

In practice, upgrading is easy. The bottlenecks are perhaps more down to perception. New technology is seen as a large upfront cost. Although in many cases it will result in a rapid return on investment, sometimes even in months. That message is now beginning to build momentum.

Another source of inertia is that electric motors are in fact very reliable. If correctly specified and well-maintained they often last for 15 to 20 years or even more. So, we find operators asking the reasonable question of why they should replace their motors that are not that old and are still performing well? The answer is that motor technology has made huge strides in energy efficiency in recent years decade. So it makes good sense both commercially and for the environment to embrace the latest technology and to future-proof their operations.

ERJ: Which new motor technologies should tire & rubber product producers be aware of?

FB: One in particular is IE5 SynRM (synchronous reluctance) liquid-cooled motor technology. This contrasts with the traditional induction motor, the most common technology used in industry, which has inherent drawbacks that arise from its asynchronous speed – such as rotor heating losses, which decrease efficiency and component and bearing lifetime.

By contrast, SynRM technology is characterised by high energy efficiency and by its reliability and low maintenance needs. Indeed, the latest IE5 SynRM versions deliver ultra-premium energy efficiency - the highest level of efficiency defined by the International Electrotechnical Commission (IEC). The usage of SynRM technology with latest available Variable Speed Drives can grant to the process the best success paired combination.

IE5 SynRM technology can also be combined with the advantages of liquid-cooling to deliver high power-density without increasing size. This means that they are equally efficient at saving energy and cutting emissions in new projects as they are in drop-in replacements for less efficient motors.

Maximum output in restricted space is ensured through the motor’s compact size, while high power-density means OEMs building rubber and plastics machinery can upgrade to IE5 efficiency with the same or even smaller frame sizes, avoiding the need for expensive redesign work and enabling more compact machines.

Also, the SynRM’s cool rotor with cooling ribs on the bearing assembly extends the lifetime of the bearings, enhancing overall reliability by reducing the chance of bearing failures – the cause of around 70% of unplanned motor outages.

ERJ: Which aspects of tire & rubber product manufacture is IE5 SynRM particularly suitable for?

FB: An important benefit of liquid-cooled motors is that they do not need fans or ventilation for cooling purposes, and therefore do not disturb the surrounding air. This can be critical for processes that are impacted by airflow, such as rubber and plastics production.

Furthermore, liquid-cooled SynRM motors improve the working environment in industrial plants, especially where noise-sensitivity is paramount.

Their torque characteristics – with a wide speed range for constant torque applications and 100% torque down to zero speed – make these motors very suitable for driving extruders.

In addition, IE5 SynRM liquid-cooled motors enable flexible and accurate control and monitoring of processes for improved overall performance and efficiency.

ERJ: How much lower is the ‘total cost of ownership’?

FB: OEMs and operators might query the need to invest in state-of-the-art motor technology when IE4 will comply with most current legislation. But we need to look beyond the upfront investment and to consider the motor’s total cost of ownership (TCO). Over a long lifetime – say 15 to 20 years - the cost of the motor is far outweighed by the cost of the electricity to power it. For a SynRM, the upfront cost is only around 2% of its TCO, maintenance accounts for 1% and the remaining 97% is spent on electricity.

IE5 SynRM motors have 40% lower energy losses than commonly used IE3 motors. Consequently, the payback time for investing in an IE5 motor instead of an IE3 motor is often under a year. In a typical application, an IE5 SynRM motor could reduce energy usage by 34,675 kWh annually, potentially leading to savings of around €5,200 and a reduction of 13,558 kg of CO₂ emissions. Over a typical 15-year life, savings would add up to €78,000 and 203,370kg of CO₂.