Focus on TCO: How you can reduce costs and increase efficiency at the same time with the right strategy

Cost reductions and efficiency increases in production: That is the goal of all investments. Drive technology plays a decisive role in this. After all, according to studies, the consumption of electric drives amounts to up to 70% of the industry’s total energy consumption. Nevertheless, many users still focus mainly on the purchase price when making investment decisions, although the costs for operation and recycling have a much greater impact. Fact is: If aspects such as energy efficiency, operational reliability, maintenance effort and variant reduction are also taken into account, it pays off in the long term. By using highly efficient technology in combination with a consistent variant reduction and standardisation, the Total Cost of Ownership (TCO) of drive systems can be significantly reduced.

Benefits of a TCO analysis in the field of drive technology:

• Comprehensive analysis of the installed drives or drives to be installed
• Determination of the energy consumption
• Calculations for the optimal number of drive variants
• Identification of hidden costs
• Evaluation of savings potential
• Careful consideration of all economic aspects
• Targeted design and consideration of the entire system

This is what you should look out for if you want to reduce the TCO of your drive systems

Drive technology is the key for reducing the Total Cost of Ownership. The optimum drive system for the customer’s individual application depends on the respective application requirements and ambient conditions and must be precisely determined for each project. In general, some factors can be identified that lead to a fast Return on Investment (ROI) and should therefore be used to reduce TCO.

Drive technology properties that contribute to the reduction of TCO:

• Lowest possible energy consumption
• Constant efficiency over a wide speed and torque range
• High overload capacity
• Great adjustability
• As few gear stages as possible
• Installation positions with minimum oil volume, especially for low ratios (keyword: reduction of churning losses)
• Compact design
• Lowest possible maintenance effort
• High operational reliability
• Long service life
• Usable worldwide
• Variant-optimised design
• Modular system

TCO in the conflicting area of energy efficiency and variant reduction

The two major factors to reduce the Total Cost of Ownership are energy consumption and the number of drive variants used. However, there is a conflict of objectives between the approaches of energy efficiency optimisation and variant reduction. Planning a system with drives that are designed for the most energy-efficient operating point leads to optimal investment costs and motors operating comparatively energy-efficiently, independent of their efficiency class. In return, many drive variants must be managed and serviced during the system’s entire life cycle. While a drive concept mainly focusing on saving energy costs leads to a large number of variants, a variant reduction has exactly the opposite goal, namely to provide the required torques and speeds in a system with as few different drive variants as is economically feasible. Thus, costs for administration, service and warehousing can be saved, but the energy costs usually increase. With view on life cycle costs, a balanced combination of variant reduction and energy efficiency can achieve high TCO reductions – particularly in large intralogistics projects for airports or parcel centres where a large number of drive units are installed.

High-efficiency synchronous motors are the key

A very effective measure for reducing the Total Cost of Ownership is the use of highly effective synchronous motors Thanks to PMSM (Permanent Magnet Synchronous Motor) technology, the motors feature a high and relatively constant efficiency over a wide speed and torque range and thus offer optimum energy consumption performance even in partial load and partial speed ranges – a clear advantage over the conventional IE1, IE2 or IE3 asynchronous technology. Therefore, they are more energy efficient in these operating points and, through a reduction of variants, also keep efficiencies at a high level, even in case of overdimensioning. This results in low Total Cost of Ownership (TCO). Synchronous motors reveal their full potential in applications with a partial load range and low speed ranges, which is the case, for example, in the areas of baggage handling, post and parcel processing. Therefore, significant cost savings can be achieved by using synchronous motors. High cost reductions are achieved over the entire product life cycle.

IE5+ motor: High power density in a small installation space

Due to the optimised power density, space savings of up to 40% can also be achieved with the compact IE5+ motor compared to conventional asynchronous motors. The same installation space can also accommodate a more powerful motor with higher energy efficiency. For example, an IE5+ synchronous motor (which provides a torque of up to 4.8 Nm) is the same size as the previous IE1 motor producing 1.24 Nm. Due to an efficient use of materials and a compact size, the IE5+ motor generation has a weight advantage of more than 50% compared to IE3 asynchronous motors within the same power range. Additionally, less volume and less weight result in reduced transport costs and are therefore more environmentally sound. The mentioned 0.75 kW motor weighs about 10 kg in the IE3 version, the comparable IE5+ motor only weighs about 6 kg. If a IE5+ motor is delivered from Hamburg to Stuttgart instead of an IE3 motor, the CO2 emissions are reduced by about 120 g per motor. Considering the fact that systems with up to 20,000 drives are not uncommon, as well as the worldwide delivery of many drive manufacturers, this demonstrates that high efficiency motors not only contribute directly to sustainability by reducing electricity consumption but also indirectly, thanks to their smaller volume and weight.

The integration of motor and gear unit has a positive impact on the TCO

By integrating the motor and the gear unit in one single housing, DuoDrive is very lightweight and compact, coupled with very high power density. Numerous wear-prone parts such as radial shaft seals are eliminated, and thus also maintenance efforts and friction losses. Reduced gear meshing and bearing points also play their part. Due to the minimised oil volume, churning losses are also lower. The DuoDrive can be mounted without any modifications using the same oil volume in various installation positions. This leads to an additional reduction in the number of variants. The compact housing dimensions have another advantage: DuoDrive has a slimmer design than competitor products and thus provides for a narrow aisle width in conveyor technology installations. As the geared motor power can be scaled in the same design without modifying the outer dimensions, plant layout modifications are not required for power adjustments.

Low Total Cost of Ownership thanks to targeted variant reduction

In addition to energy consumption, targeted reduction of the drive variants used also offers great potential for optimising the Total Cost of Ownership. A variant is a combination of gear unit, motor and frequency inverter available in different sizes and gear ratios. Variants may be reduced by using only one geared motor and frequency inverter size for a specific speed and load range. Controlled via the frequency inverter, this drive unit may then cover all required operating points for lower performance requirements or other speed ranges.

Significant cost savings

When reducing the number of variants, project costs tend to rise slightly because larger drives are used in some cases, which leads to additional costs compared to customised dimensioning. In return, however, the operator benefits from optimised operation of their system and significant cost savings in the areas of administration, service and spare parts stocking over the entire service life of the drives. The system integrator also saves costs, for example in engineering, through a systematic variant reduction.

This is how you benefit from a reduction of variants:

• Energy costs: An analysis and consideration of the actual load conditions (keyword: partial load) can achieve permanent energy cost savings. Positive side effect: a smaller carbon footprint.
• Engineering costs: Fewer variants have to be designed and processed in the engineering process. This simplifies the drive selection and visualisation of the system.
• Administrative costs: Fewer part numbers and variants have to be managed. This facilitates the maintenance of part lists and reduces the procurement effort. At the same time, fewer incorrect installations or incorrect orders result in lower error costs.
• Documentation costs: Documentation efforts are reduced thanks to standardisation and reduction of variants.
• Training costs: Easier maintenance, commissioning and parameterisation also means reduced training effort.
• Spare parts costs: Fewer types of spare parts and fewer parts in stock result in less capital commitment for the spare part stocks and fewer errors in ordering and installation.
• Commissioning, service and maintenance: Standardisation, modularity and plug-in capability facilitates maintenance and commissioning as well as repairs. Service intervals and measures become easier to plan, and plug-and-play installation saves a lot of time and effort. Additionally, there is the excellent support from the NORD DRIVESYSTEMS global service network.

Find out more about TCO

Would you like to find out more about how drive technology can help you reduce your Total Cost of Ownership? Download our white paper “Total Cost of Ownership: Drive technology is the key for reducing the Total Cost of Ownership” and find out more about savings potential, optimisation options and how NORD realises TCO reduction.

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