Evaluating and improving energy performance requires good information on how, when, and where energy is being used. The purpose of the analysis performed in the prior step (2.4) is to provide a basic overview of your organization’s energy supplies. In this step, you will determine where and how this energy is used in your organization’s operations. The process of identifying the systems, equipment and processes that use energy and determining its respective impacts on energy consumption will allow your energy team to focus their limited resources on areas that have the most significant impact on energy consumption. A simple energy balance of the systems, equipment and processes in the organization’s operations is a good starting point for determining the significant energy-using systems.
Advancing from Foundational Level 1 to ISO 50001 Level 2 for Step 2.5
Identification of significant energy uses (SEUs) is a requirement of the ISO 50001 standard. In implementing foundational energy management (Level 1), the significant energy uses were the big energy consumers. In ISO 50001 (Level 2) a significant energy use can be the big consumers or an energy use with considerable opportunity for improvement, or a combination of both. You developed an energy balance at Level 1 and you will use that at Level 2 to ensure you have accounted for all energy consumers. You will use additional data to help with organizing the energy uses in a fashion more conducive to determining the SEUs as required by the ISO 50001 standard. SEUs can change over time and you must develop a systematic approach for reviewing and updating the SEUs as necessary.
Once the SEUs have been determined, you must identify the relevant variables and understand how they impact the SEU’s energy performance. You must also determine the SEU’s current energy performance and implement measurement and monitoring to continually evaluate the energy performance of the SEU. Your organization determines an appropriate metric for determining energy performance of the SEU; however, an energy performance indicator (EnPI) is a typical measurement. Finally, you must develop an estimate of future energy consumption for your SEUs to help with evaluating the energy performance against expectations.
2.5.1 Prepare a list of major equipment and systems
The first task associated with determining your significant energy uses (SEUs) is to prepare a simple list of all your major equipment and systems. To do this, take a moment to review the Energy Uses Checklist that you filled out in Step 2.2.2. Using this broad list of energy uses to guide you, prepare a specific list of all the major equipment and systems used by your organization. Utilize the Energy Uses sheet of the DOE Energy Footprint Tool to make your list. You can refer to the Example Commercial Buildings Equipment List and the Example Industrial Plant Equipment List to help guide you.
2.5.2 Develop an energy balance
Now that you have made a list of equipment, the next step is to estimate the annual energy consumption of each piece of major equipment. Identifying which systems, equipment, processes, and operations use the most significant amounts of energy will help you better understand where you have the greatest opportunities to improve your organization’s energy performance.
The most accurate way to do this is to meter your individual pieces of equipment, but your organization may not have this sub-metering installed. Instead, a simple method to help you get started is to perform a simple energy balance based on load estimates for the equipment and systems operating at your facility. The sum of this bottom-up estimate can be balanced against your top-down energy purchases. If you make good assumptions about equipment energy consumption, the systems-level estimate should be within ±10% of your energy purchases.
You may want to use the DOE Energy Footprint Tool to develop an energy balance for your organization. The Energy Footprint Tool assists the user in balancing the amount of energy calculated from the aggregate of major equipment, systems and processes relative to the total energy of all energy sources.
DOE Energy Footprint Tool: This tool helps you organize your organization’s energy related data. The Energy Footprint Tool allows you to enter data on a monthly basis for up to 10 years for a variety of variables.
Example Energy Balance: This document shows screenshots of the input and output of the Energy Footprint Tool energy balance functionality.
Plant Energy Profiler: The Plant Energy Profiler, or PEP, is an online software tool provided by the U.S. Department of Energy to help industrial plant managers in the United States identify how energy is being purchased and consumed at their plant and identify potential energy and cost savings.
EPA ENERGY STAR Guidelines for Energy Management: Contains a step-by-step road map for continuous improvement, based on best practices as compiled by the EPA ENERGY STAR Program. Refer to Step 2.1 of the ENERGY STAR Guidelines for guidance specific to eGuide Step 2.5.
Energy Management Package for Small Commercial Buildings: Best practices guide and energy management package for heating, ventilation, and air conditioning (HVAC) contractors to deliver energy management services to small commercial buildings. Refer to Element E3 of the Package for guidance specific to eGuide Step 2.5.
Sustainable Energy Authority of Ireland (SEAI) Energy MAP: SEAI’s Energy MAP tool provides a step-by-step guide to creating a best practice action plan for energy management. Refer to Step 7 of the SEAI Energy MAP for helpful guidance specific to eGuide Step 2.5.
