Meet Sustainability Goals with Energy Measurement and Management

Summary

The use of utilities is directly correlated with profits and carbon footprint, incentivizing companies to minimize consumption, while upholding safety and quality. Utilities are a necessary expenditure, but there are almost always opportunities for savings, which can help companies reduce operational costs, increase product margins, and meet ambitious environmental stewardship targets. 

Central to both operational efficiency and energy savings are the ability to squeeze as much production or output from the smallest net input possible, while maintaining high safety, quality, reliability, and uptime. However, proper energy management requires accurate data capture and appropriate analysis. None of this is possible without reliable instrumentation to monitor plant processes and utility consumption. 

Utilities can be broadly placed into two camps. Tier-one utilities are typically purchased directly from an external supplier, including electricity, water, liquid fuel, and various industrial gases. These are used directly to power many operational components within a facility, but additional general-purpose products are also required to run particular processes such as purging or cooling. These tier-two utilities—created from tier-one supplies—include steam, compressed air, treated water, and heat. This information empowers plant personnel to establish baselines, monitor process efficiency, identify opportunities for savings. 

There are many areas for potential savings in steam, compressed air, heating, cooling, and industrial gas usage. These are common process inputs for plant operation in many industry sectors, and vast quantities of energy are expended in the production and distribution of these utilities. This is why identifying opportunities for consumption reduction in plant processes is so critical. 

For example, steam drives heat exchangers, distillation column reboilers, and similar applications because it is an efficient and controllable mechanism for delivering energy precisely where it is needed. But it is also expensive to produce and distribute, which calls for careful measurement and control. 

Comprehensive utility monitoring and optimization can regularly reduce energy consumption by 5 to 15 percent, but this requires establishing the right energy performance indicators (EnPIs) and making appropriate process operational tweaks or investments. Reduction opportunities depend on instrumentation that can objectively quantify energy flows, energy consumption, and process data according to ISO 50001 and ISO 50006, with related systems presenting this data in terms of EnPIs. 

Guidance from standards 

ISO 50001 is a universal energy management standard, specifying the establishment of EnPIs for setting up an energy management system. These indicators must be regularly reported, checked, and compared against an energy baseline (EnB) created prior to introducing measures for increased energy efficiency (Figure 1). 

Based on this information, potential areas for savings are evaluated, and improvement measures can be initiated for single processes as well as throughout buildings, plants, or entire factory complexes. 

The ISO 50006 standard provides step-by-step guidance to companies for defining robust EnPIs and an accurate EnB for later comparison. The standard also contains several real-life examples, which are helpful because it can be difficult to initially identify relevant variables in an energy system from which to determine EnPIs. Such variables include weather conditions, balance period, plant size, production variations, and energy sources, to name a few. 

Common EnPI examples include: 

• Adjustment for primary energy demand (MWh/year) 
• Total primary energy consumption (MWh/year) 
• Improvement in energy intensity for the baseline year (percent) 
• Energy savings for the current year (MWh/year) 
• Total consumed primary energy (MJ/year) 
• Energy savings since the baseline year (MWh/year) 
• Improvement in energy intensity for the current year (percent) 
• Electricity, water, or fuel consumption (total values, peak loads, etc.)  
• Specific energy consumption, i.e., energy consumption per quantity of produced media, like compressed air (kWh/Nm3), steam (MJ/t), and hot water (kW/kg) 
• Efficiency of steam boilers (percent). 

Software-aided savings 

Installing instrumentation across flow, temperature, pressure, and other critical measurements is crucial for energy management systems, but these systems are not complete without a means to visualize measured values and energy data. This element is the basis for detailed evaluation, compliant with the ISO 50006 standard. 

Energy management software is used to analyze measurement data and create energy reports, and the applications on the market today typically provide access to entire plant monitoring systems via an internal intranet or the Internet. The best software packages incorporate: 

• Web-based secure local or remote access 
• Automatic data import from data loggers, supervisory control and data acquisition (SCADA) systems, production systems, and building management systems 
• Simple operation and easy-to-use interfaces with drop-down menus 
• Simple integration into existing operating data recording systems 
• Modular application design for simple customization 
• Simulation and calculation using multivariate mathematical functions 
• Energy analysis that includes energy consumption monitoring, efficiency assessment, target/actual energy data comparison, and peak values identification 
• Cost analysis: 
  • Create diagrams and displays. 
  • Create and monitor budget plans. 
  • Cost comparison. 
  • Profitability calculations in terms of return on investment. 
• Deviation analysis: 
  • Email notifications and warnings 
  • Limit value adjustment 
  • Notification prioritization. 
• Reporting: 
  • Tailored reports via SQL Server Reporting Services 
  • Cumulative curve calculation and comparative displays 
  • Automatic report creation and sharing capabilities. 

Measurement for monitoring 

Getting started can be overwhelming. However, reliable instrument installation lays the foundation for effective energy management system rollouts (Figure 2). Engaging the right experts can ease the journey from first steps to final refinements by providing end users with high-quality instrumentation, system components, software solutions, and support. 

Components and services to look for in an industry partner include: 

• Robust instrumentation with high accuracy, reliability, and repeatability 
• Smart devices for data logging and transfer 
• Engineering and project management for single applications—e.g., boiler efficiency monitoring—and system-wide solutions 
• EMAS- and ISO-compliant calibration services 
• Professional planning, commissioning, and maintenance of energy monitoring and management systems 
• Expert support from qualified specialists 
• A wide-reaching service network. 

Looking toward a sustainable future

_{This feature originally appeared in the March edition of AUTOMATION 2024: IIoT and Digital Transformation.}