For manufacturers, managing energy use is essential to cut costs, improve efficiency, and reduce footprints. Every dollar saved on utilities directly boosts your bottom line. For instance, saving $10,000 per year on energy is like adding $100,000 in sales every year (assuming a 10% profit margin). By reducing expenses like utility costs, you increase profit margins on every product sold.
In the manufacturing industry, every dollar of extra profit strengthens your company’s financial stability. Plus, lowering energy use reduces Scope 1 and 2 greenhouse gas emissions, helping you meet carbon reduction targets and customer expectations. With growing pressure from both business customers and consumers to reduce emissions, having a system that provides reliable data to set and track reduction goals is essential. This is especially important for companies looking to comply with the Science Based Targets Initiative (SBTi), carbon disclosure project (CDP), and other initiatives that offer a trusted method for validating carbon data.
What is an Energy Management System (EMS)?
According to the International Standards Organization (ISO)
An energy management system involves developing and implementing an energy policy, setting achievable targets for energy use, and designing action plans to reach them and measure progress.
What is an Energy Management Information System (EMIS)?
Another common term you may have heard is an energy management information system (EMIS). The U.S. Energy Department explains that an EMIS is “…comprised of devices, data services, and software applications that monitor, analyze, and control metered building energy use and system performance…”. The devices that provide the data to the software applications are typically sub-meters that log electricity, natural gas, and even water (more on that later on). In essence, an EMIS is a tool that helps track and retain gains achieved by an EMS.
Robust Energy Conservation Programs Use Both an EMIS and EMS
An EMIS essentially provides the hard, cold facts about energy performance by collecting, analyzing, and reporting data through a software interface to support organizational decisions. An EMS provides the comprehensive policies, protocols, and procedures needed to act on the results in the context of an organization’s energy goals (such as driving change in facility energy performance, tracking results against reduction targets, knowing when and where to implement an effective energy efficiency measure, alignment with continuous improvement strategies, etc.)
A robust energy conservation program for a manufacturing facility would employ a combination of EMIS within an EMS to deploy a comprehensive energy program to log, analyze, monitor, and adjust energy-consuming equipment and processes to optimize energy performance. Even a building automation system (BAS) can optimize aspects of a Heating Ventilating and Airconditioning (HVAC) systems. However, a broader EMIS system can optimize HVAC as well as process-related energy management (where energy use can fluctuate based on throughput, product type, changeovers, maintenance shutdowns, etc.).
In this scenario, an EMIS system can relay process-related energy data to software that can alert staff to energy consumption out of range of a preset threshold. This is where the EMS takes over, as it includes protocols for how to interpret the alerts and what action(s) to take. As such, it is key that human intervention is applied to interpret the EMIS data and alerts and decide on the appropriate course of action in operational context.
The figure below illustrates this.
EMIS and EMS for Determining Energy Use Baselines in Manufacturing Facilities
The combination of an EMIS and EMS helps set energy consumption baselines, which are important for tracking the results of energy-saving measures. For example, an EMIS can measure and record how much natural gas a steam boiler uses in a manufacturing plant to create a baseline for energy consumption. An EMS considers factors like seasons, production rates, and peak production times when calculating this baseline. Tools like CUSUM and regression analysis can help verify the baseline, either through the EMIS software or manually. Energy use can also be visualized using tools like a Sankey diagram or thermal balance pareto, either within the EMIS or as a separate EMS tool.
EMIS and EMS for Tracking Changes to a Process
Once a baseline is established, changes to the process can then be seen through the EMIS data and analytics. For example, if an EMS team installs a heat exchange system to pre-heat boiler makeup water using waste heat from another process, the resulting drop in natural gas consumption can be observed via the EMIS. Since the baseline consumption already considers the variables mentioned above (weather, production rate, etc.), the observed drop in thermal energy use in the EMIS analytics can be attributed to the implemented energy efficiency measure.
EMIS and EMS for Tracking Decarbonization, Net Zero, and Other Sustainability Initiatives
This type of measurement is crucial for facilities with decarbonization or carbon reduction goals. For example, an EMIS not only tracks energy savings but also calculates the drop in greenhouse gas (GHG) emissions from using less natural gas, for example. If a facility switches to electric boilers as part of a decarbonization plan, the EMIS can measure and report the GHG reductions by tracking the increase in electricity use and the decrease in natural gas consumption. By applying emission factors for both electricity and natural gas, the net GHG reduction is calculated. The EMS then compares this to the expected reduction target, determining if the savings are on track or if further measures are needed to meet the goal.
Real-World Examples of an Energy Management System in Action
We’ll use a few real-world examples from manufacturing facilities to illustrate the above key steps and to illustrate the importance of a combined EMIS and EMS.
At a food manufacturing facility, although overall energy and water consumption were being tracked at the utility level, devices such as amp loggers, natural gas meters, and water meters were installed on key processes as part of an EMS initiative.
One of the key processes that had amp logging deployed was the facility’s air compressor system (in manufacturing facilities, air compressors can use a signification portion of electricity). Furthermore, only about 10-30% of the electrical energy is used to compress the air (the rest is lost to heat). As such, minimizing air compressor energy use cuts out a significant portion of wasted energy (a concurrent process integration study by Enviro-Stewards is exploring reusing the waste heat as a heat source for other processes).
Logging data of the air compressors through an EMIS (Stewwi) revealed that even under light load (minimal need for air for production), the air compressors were unnecessarily consuming over 250 kW of energy. This type of higher-than-expected energy consumption is commonly due to air leaks within the distribution system and at end users. It was estimated by the project engineers that the leaks accounted for almost half a million kWh of unnecessary electrical consumption ($36,000/year).
Therefore, it was recommended that an air leak survey be conducted by the facility team. Following completion of the survey and repair of the leak sources, there was approximately a 50 kW decrease in total compressed air electrical use. This can be seen in the figure below.
Continuous monitoring of the air compressors using the EMIS revealed that the total compressed air power consumption was slowly creeping up again – indicating that new leaks are developing. This type of insight into energy use provided by an EMIS can help facility staff know when to conduct another air leak survey as part of their EMS policy.
The Benefits of Including Water Conservation as Part of Your EMS
Although an EMS typically doesn’t necessarily include water consumption, we include it in our Stewwi system because there is strong overlap between hot water and energy consumption (e.g., combustion of natural gas to heat the water). Additionally, electrical energy might be required to pump water throughout the facility and to evaporate water through a rooftop cooling tower, for example. As water rates continue to rise in most jurisdictions, reducing water use can save a company a significant amount of money.
A food manufacturing facility committed to reducing its process water consumption as part of its overall sustainability initiatives. To accomplish this, Enviro-Stewards conducted a walkthrough of the facility over a weekend when there was no production to locate sources of unnecessary water use. The team found four water conservation opportunities (overflowing tanks, stuck float valves, etc.) that were not required on the weekend (nor during weekday production). Data from the EMIS (that incorporated water metering) was used to confirm and quantify the water savings (see figure below, where green arrows indicate an implemented conservation measure and the corresponding drop in total facility water consumption recorded by the EMIS).
In total, the team identified and implemented immediate water conservation opportunities that will save the facility nearly $100,000 per year in water costs! As some of the savings was hot water, the measures will also save natural gas costs.
With the above two examples, we can observe that monitoring alone through an EMIS doesn’t optimize energy (or water) use or on its own lead to conservation opportunities. It’s the combination of intelligent interpretation of the data and human intervention on the plant floor that ultimately generates the savings (EMS). That’s why a key component of any EMS system is regular analysis by a human to properly interpret the data and decide when and if an intervention is needed based on the company’s EMS policy.