An Energy Management System (EnMS) according to ISO 50001:2018 provides companies with a strategic tool to help manage the performance of energy-consuming equipment, including compressed air systems. Improved performance of a compressed air system, in turn, can go a long way toward lowering energy costs and improving system uptime, both of which provide the ability to reduce the company’s carbon footprint. Here’s a look at the standard and important considerations involved in the implementation of an EnMS for a compressed air system according to ISO 50001.
A Framework for Energy Management
ISO 50001:2018 is based on the management system model of continuous improvement and is also used for other well-known standards, such as ISO 9001 (quality management) or ISO 14001 (environmental management). This makes it easier for organizations to integrate energy management into their overall efforts to improve quality and environmental management. The standard provides a framework of requirements for organizations to:
- Develop a policy for more efficient use of energy.
- Fix targets and objectives to meet the policy.
- Use data to better understand and make decisions about energy use.
- Measure the results.
- Review how well the policy works.
- Continually improve the EnMS.
From a more practical perspective, you could say ISO 50001 consists of about 20 pages of “common sense” and it is a “one size fits all” standard. So every company that consumes energy should implement EnMS according to ISO 50001 from the biggest global corporates to the smallest workshops. The intention is of course to implement a system adjusted to the size and the activity level of the individual company. In other words, there will be a relatively huge difference between “big” and “small” companies concerning the complexity of the systems, although the standard is the same.
An EnMS according to ISO 50001 can in very many countries be certified. Some bigger companies may have a certified ISO 9001 system in place, but this does not exclude other companies from picking the “best” parts of the standard that bring energy savings, along with a lower carbon footprint. However, it is very much recommended to follow the standard in detail concerning the parts you implement, if/when you later decide to go for an ISO 50001 certificate.
The ISO 50001 standard includes a term called Significant Energy Use (SEU). In short, SEU addresses energy-consuming equipment that consumes a significant part of the total energy of the company and/or offers a considerable potential for improvement in energy performance. In that sense, a compressed air system fits extremely well into SEU (ISO 50001). As in many companies, compressed air consumes 5 to 15 percent of the total electricity consumption of the company and generally offers potential projects with a payback time within three to nine months, which is often referred to as “low hanging fruit.”
Start with Mapping for EnMS Implementation
Of course, implementation of EnMS requires resources to implement, but in the beginning it is often about top management’s decision to start the process, while also making time, data and staff available, than it is about big investments. Generally, it is more about the need to change the culture in the company, including an understanding of energy and energy services, as well as production process demand. It is also about the decision to commit to continuous improvement, including monitoring of energy-consuming equipment, and training of staff at different levels, including operators, maintenance teams etc.
Once you have decided to call your compressed air system a SEU, a good place to start with EnMS implementation in accordance with ISO 50001 is to map your compressed air system. You may have diagrams about the system available, but it is a good idea to check if these diagrams are in accordance with reality; alternatively create some new ones if they do not exist, or they have not been updated for a long time.
Mapping should also include location of the equipment (air compressors, dryers, filters, storage), nameplate data about the equipment and pipe sizes. Do you have flow meters and/or energy records available? Maybe not, but you usually have some pressure gauges available (e.g. at the storage), and via the individual air compressor controls, access to data about total and loaded hours of operation (fixed speed screw air compressors) and the pressure settings of the air compressors.
Energy Baseline: An Important Reference Point
If you before considered compressed air to be just a source of energy supplied via e.g. a 4-inch pipe through the wall, you will probably (after a mapping) be surprised about a few things. This includes how expensive it is to generate compressed air from an energy point of view, and how complex it can be to operate and maintain air generating equipment, compressed air treatment equipment and pneumatic equipment in general – the “efficient way.”
If you only have limited knowledge about your compressed air system, it is very much recommended to get some help in the beginning. Finding an experienced compressed air consultant is the safest way of getting a good result. Make sure the audit or the review of the system includes the demand side of the system, NOT only the compressed air station! If you do not include the demand side, you may end up in a situation, where you generate compressed air the most efficient way possible and then waste half of it by leaks, inappropriate use of compressed air and artificial demand, just to mention some demand-side issues.
You will probably know much more about your compressed air system after a review, so after this initial approach you may feel tempted to take immediate action to save some energy. Specifically, you may be inclined to pick low-hanging fruit that allows most plants to achieve an energy savings potential of more than 5% - and in many cases – as much as 10 to 30 percent with an acceptable payback time.
But before you get addicted to “easy savings,” an important consideration is to develop an Energy Baseline (EnB). This will create a reference point to evaluate projects or actions you implement. An EnB will also make it easy to document the results of your efforts and avoid investments in expensive projects that do not bring the expected savings. In addition, this contributes to continuous support from top management, which is very much needed in relation to effective operation of an EnMS.
Continuous Improvement Calls for Key Performance Indicators
You can start from scratch concerning EnMS according to ISO 50001 and with compressed air as a SEU, but the term “continuous improvement” in the standard commits you to demonstrate the energy performance of the company. This creates the need for Key Performance Indicators (KPI’s), which in the standard, are called Energy Performance Indicators (EnPI’s.) You will also need to develop your “data collection,” possibly starting from the beginning and looking at data recorded manually, but evolving to something better and probably more sophisticated. Of course, any energy monitoring system should be able to “pay for itself” in a reasonable time through the energy savings achieved.
When it comes to compressed air, you may need to operate using more KPI’s. For example:
- Total Energy Consumption: The energy consumption in kWh of a compressed air system on a monthly basis, e.g. [kWh comp. air/month]. Total Energy Consumption (compressed air): In this example, it is influenced by a relevant variable (could be production output) that impacts the energy performance and routinely changes, as shown in Figure 1.
- Specific Energy Consumption (production): This metric is the ratio of compressed air energy consumption divided by some specific production output, e.g. [kWh comp. air/tons of production] on a monthly basis.
- Specific Energy Consumption (compressed air): This metric is the ratio of compressed air energy consumption divided by the compressed air output, e.g. [kWh/Nm3].
- Portion of Non-productive Usage: This is the proportion of the airflow during non-productive periods divided by the average airflow, calculated in percent [%].
Shown is the correlation between production measured in tons/month and the consumption of compressed air measured in kWh/month in a one-year period. The equations depict targeted reduction in energy use by 12% through measures such as the repair of the compressed air leaks. When 2019 has passed, it will be easy to document whether the actions performed were sufficient, or whether maintenance needs to be further improved. Click here to enlarge.
Monitoring Systems Provide KPI Visualization
An obvious question for many is why there needs to be more than one KPI/EnPI. The answer to question is best described by example.
Imagine you have performed a compressed air leak survey and subsequently fixed some leaks in your compressed air system, which reduced demand for compressed air by 12%. This action will of course reduce the total energy consumed by the air compressors, but your air compressors may now operate more part loaded, and the SEC (compressed air) may increase, indicating there is a further room for improvements, such as the need to operate your air compressors differently, install a master controller, or invest in Variable Speed Drive (VSD) technology, etc..
Depicted is a more advanced monitoring system where the different air compressor combinations are represented by different colors. Real-time data shows, for example, that with a demand for compressed air of approximately 108 m3/min, there is room for an improvement of up to 25% in the SEC, however, only at certain times. The solutions can be different, for example, with the implementation of a master control system and/or variable speed drive technology, or perhaps just a simple improvement of air compressor settings.
In the long run you will probably find it valuable to use a monitoring system to keep an eye on compressed air system performance. A monitoring system allows you to visualize KPI’s in an appropriate way, including pressure dewpoint etc. The system will also be able to divide compressed air costs into different cost centers, or production departments. A clarification of the consumption of energy services usually brings more awareness – and with that, energy savings.
ISO 50005 Standard Under Development
A new EnMS standard for small and medium-sized enterprises (SMEs) is under development, called ISO 50005. The standard is intended to make it easier for SMEs to introduce energy management systems. The standard, which is also referred to as a guide, suggests you implement energy management systems step by step, depending on how mature your business is.
The company itself must assess how mature it is based on a maturity model the standard specifies. The model gives guidelines from the starting point to the full implementation of energy management; this in step with the stages of maturity in your company.
ISO 50005 is to become part of a larger ISO family of energy management standards and is expected to be completed in two to three years. As such, it is not expected to change anything in the approach to compressed air efficiency, only to make it more manageable for SMEs to implement an EnMS.
About the Author
Bo Kuraa is Vice President Technical, Enersize, tel: +45 51254920, email: firstname.lastname@example.org.
With its proprietary patent-pending automated software for leakage management, data collection and analysis, Enersize can provide 10 to 50 percent energy savings in industrial compressed air systems. Through the recently acquired LEAQS system, the company has access to more than 9,000 leakage management projects, and is associated more than 4,000 customers worldwide. The company is headquartered in Helsinki, Finland. For more information, visit www.enersize.com.