Manufacturers need to understand what energy is being consumed – where, and when. They need to pull this information from their production systems. They also need to be able to act on this information to make informed decisions that deliver savings – this requires a level of control. 

To reduce energy use requires a strategic approach built on four key stages: monitor, analyse, control and sustain.

Monitor

An effective moniotoring programme requires a network of digital monitoring devices at its centre to retrieve and record consumption data. Such devices are used to measure the actual energy use parameters of a specific system within a plant, such as electricity, natural gas, water and wastewater.

Data gathered can be collated into information regarding the overall power consumption from different areas of the plant, such as production lines or even single machines. Understanding the energy use profile can lead to remarkable findings, such as the amount of power used when there is no production, which can be up to 70% of the load when fully operational. This is a good starting point to reducing cost.

Analyse

With the foundation of monitoring, data use analysis can be employed to bring about immediate savings. Software can be used as a centralised repository for energy use parameters within a plant or across multiple plants. Such software can help managers to see where issues may exist and help them identify corrective measures. Similarly, the software can create models and energy profiles by measuring peak demand and power-quality parameters, identifying patterns in demand, tracing use against variables such as the weather, aggregating loads and calculating the cost of energy acquisition.

For this kind of data analysis to be effective, data must flow smoothly and without corruptions from plant floor to management systems. Such a system requires integration of power monitoring devices, control technologies, communication networks and visualisation tools into a single system which brings together an accurate picture relating energy consumption to plant activity.

With such an array of devices and technologies required to complete the picture of energy consumption for analysis, a simple, open communication network such as EtherNet/IP or DeviceNet, via wired or wireless networks can be used to minimise complexity.

Control

Having analysed the data plant managers are now in a position to implement an automated control system to deliver savings according to the specific needs of the plant.

Some plants, for example, will be seeking to draw down a more consistent energy load over time and might install a load management system to monitor the use of electricity in selected equipment. It may be possible to turn off certain elements of the plant during peak times and operate them when less energy is being required, thereby evening out demand. A food manufacturer looking to make their filling and processing equipment more energy aware might turn off air supply lines when there is no throughput on the machine or line. Compressed air control and optimisation systems control starting, stopping, staging and blowoff functions of an air compressor system, helping to achieve energy-management goals.

Sustain

It is important, but not easy, to continue to prioritise an approach that treats energy as a commodity in order to sustain the benefits of an effective energy management strategy. The energy use footprint of a plant is constantly changing and it is vital that data is continuously tracked according to output. When data is not tracked and related to production output often enough, it can appear that the initial energy-consumption investments are not paying off. To sustain an effective energy management strategy, the following methods can be very useful:

•  Keep energy consumption as a priority in operational decision making

•  Communicate the benefits of energy savings within the organisation as they happen

•  Extend power- and energy-monitoring solutions to support continuous-improvement efforts

•  Review KPIs monthly

•  Complete a yearly energy management assessment to keep the strategic plan on track.