Energy: Ever important

By Teemu Turunen and Jaana Kuorelahti, Metso's Paper and Fiber Technology

BRUSSELS, Nov. 7, 2011 (RISI) - The European Council decided in March 2007 on the EU's main objectives for climate policy up to 2020. According to the decision, the EU is committed to reducing emissions by 20% from 1990 levels, regardless of the actions of other countries. The decision also states that the EU will automatically raise the target to 30% if an international agreement is reached committing other industrial countries to comparable reductions and the economically most advanced developing countries to emission reductions. To reduce the emissions, the European Council states that the proportion of renewable energy sources in the common consumption of energy must be increased to 20% within the EU area. As for the reduction target, the efficiency of the end use of energy is the most significant factor in the CO₂ reduction target. Comparisons of IEA's 450 ppm scenario and the reference scenario show that the effect of energy efficiency on the whole is over 50%.

In practice, the measures are implemented by utilizing well-proven methods and technologies (BATs). Improving the efficiency of BAT requires product development and transition to the use of completely new technologies.

In practice, the BATs for industry are divided into the following areas:

• Management of energy efficiency.
• Planning of targets and goals.
• Identification of energy efficiency and energy saving potentials.
• System approach to energy management.
• Implementation of energy efficiency targets and indicators.
• Benchmarking.
• Energy-efficient planning.
• Adding process integration.
• Energy efficiency work at the plant.
• Maintaining knowhow.
• Efficient process control.
• Maintenance.
• Follow-up and measurement.

As the list shows, efficient monitoring of energy efficiency affects several factors. Comprehensive monitoring helps manage energy efficiency, finds energy saving potential and enters sufficiently deep in the process through a system-oriented approach. It can also be used to maintain knowhow, as well as for other energy efficiency work at the target location. Correspondingly, reporting can be utilized to manage and implement energy efficiency targets, benchmark and plan targets and goals. It has been estimated that the improvement potential available through monitoring and control of energy efficiency would be approximately 5% of industrial processes without the process control system update.

The user plays a key role

Energy savings are not necessarily achieved merely by applying new technology. Instead, the user of the applications and equipment has in many cases a key role. From the perspective of energy efficiency, this has been rarely studied in industrial processes. However, the transportation sector has detected that the difference between economical and uneconomical driving can be more than 30%. A person must have enough information about correct practices to change his operating methods. The structure and content of the user interfaces play an important role as a boundary layer between the user and the process. A good user interface promotes the management of the processes and systems. The user interface design must be specifically addressed when the user is new to the subject in question. Figure 1 shows factors addressed in the user interface design.

Figure 1 - Factors in a good user interface design

The feedback given through consumption monitoring and its effects in households have been studied.

• Feedback is most efficient when it is up to date and easily available.
• Feedback must be consumer-specific.
• Comparisons with earlier consumption data is important for consumers to adopt feedback and react to it.
• Graphic comparison with other households in the home electricity bill motivates consumers to change their habits.
• The method and form of giving feedback have not received enough attention.
• Involving consumers in the feedback design makes the feedback more efficient.
• Well-designed consumption feedback included in the bill is an inexpensive and easy way to cut down on consumption.

Another study showed that user-friendliness is also important in developing new indicators and displays for giving feedback. According to the study, the best displays show at least momentary, that is, real-time consumption, costs and provide historical data of the consumer's own energy consumption. Displaying tariffs and carbon dioxide emissions would bring additional value. The design of energy consumption applications should consider factors such as the display location at home, motivation (e.g. financial, competition with others or oneself), parameters (kWh, CO₂ emissions, money), appearance (diagrams, figures, tables), period of time and what energy is measured against (room, total costs, person, etc.). Unfortunately, there is very little research data on what an individual's own consumption could be compared with to achieve the highest savings. Target setting appears to be an efficient way to reduce consumption.

Monitoring energy efficiency on a papermaking line

An examination of the implementation and architecture of the automation system of a typical papermaking line shows that the system is in many cases very advanced and comprehensive. It allows transferring data between different systems as well as processing it further to the needs of various user groups. In many cases, these features have not been fully utilized in monitoring energy efficiency. A good example of this is the paper machine sectional drive power often found in the drive control system.

Energy efficiency-related measurement instrumentation is often insufficient. For example, the following line-level basic indicators cannot always be defined with the existing instrumentation.

• Specific steam consumption (t_steam/t_paper).
• Specific electricity consumption (kWh/t).
• Total energy consumption (kWh/t).
• Energy costs (€/t).
• Specific water consumption (m³/t).
• Compressed air consumption (ksf/t).
• Condensate return percentage (%).

In addition to calculating the indicators, they must be presented in an illustrative and comprehensive manner. If the indicators are to be displayed in the machine control system, they should be provided with a separate hierarchical structure in the system.

The stages of the development project for the energy efficiency monitoring system in a papermaking environment can comprise the following:

1. Measure the energy consumption of each line separately.
2. Define the key indicators of energy efficiency.
3. Highlight the most significant parameters affecting energy efficiency.
4. Integrate energy efficiency parameters as part of operator work.
5. Encourage the staff to make continuous improvement.
6. Add energy costs and their reductions to the agenda of production meetings.
7. Execute fixed-period rounds of energy efficiency for key processes.
8. Benchmark the line in relation to BAT and other equivalent machines.

Motivating an employee plays an important role in the examination of an industrial plant. Motivating through cost savings is not typically as efficient when working within an entity owned by someone else. A good example of this is a Finnish papermaking line, where the interest in energy efficiency had been implemented in practice through a well-functioning initiative system, so the user of the process also benefited from self-invented energy efficiency measures.

To be continued ... Read Part II here.

Teemu Turunen and Jaana Kuorelahti, Metso's Paper and Fiber Technology, teemu.p.turunen@metso.com

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