An Energy Management System (EMS) is a software or web-based application that enables the monitoring and supervision of buildings’ energy-related metrics. Through an EMS, building operators can evaluate systems’ energy performance, visualize energy consumption patterns, and identify energy waste sources. EMS data provides valuable insights for operators to make informed decisions from an energy consumption and efficiency standpoint.

Buildings Energy Statistics

The U.S. Energy Information Administration (EIA) reported that in 2022 the electric power consumption of commercial buildings in the U.S. accounted for 35% of the total electric system output.

Commercial buildings’ main source of energy is electricity generated by the power utility providers. In fact, electric power represents 49% of the total energy used by commercial buildings, followed by natural gas, which accounts for 39% of the total.

Buildings Energy Consumption Pattern

Considering the major energy sources, on average, commercial buildings’ energy consumption distribution by end use follows the pattern below:

• Heating, ventilation, and air conditioning (HVAC) account for 52% of total building energy consumption.
• Lighting, water heating, cooking, and refrigeration add up to 27% of the total.
• Computing, office equipment, and other loads complete the remaining 21%.

Energy Waste in Commercial Buildings

According to Energy Star, on average, 30% of the energy consumed in commercial buildings is wasted.

There are basic practices that can contribute to mitigating energy waste in commercial buildings such as:

• Turning the lights off in unoccupied rooms.
• Resetting room temperatures when there is no occupancy.
• Setting up proper water heater temperatures.

Although these measures can help reduce energy waste, they are not frequently implemented in large facilities or commercial buildings, and there is a common reason behind it.

Main Cause for Energy Waste in Buildings

One of the most common reasons behind commercial building excessive energy waste and inefficiencies is the additional mechanical, electrical, plumbing and control complexity that commercial building systems exhibit compared to residential single family home counterparts. The gap in system complexity is very wide in some cases, particularly the HVAC system.

This added complexity is a barrier to operations, requiring owners and management companies to have an in-house person or consultant with in-depth knowledge, experience, and understanding of these systems, so they can be efficiently managed, operated, and maintained. In other words, the lack of qualified and properly trained building operators is costing hundreds of thousands of dollars in the form of energy waste and other system inefficiencies.

Buildings Energy Management Landscape

Most buildings don’t have an energy management system in place and instead follow a reactive approach when it comes to energy management. In other words, every month operators check the power bills from the utility company, and if there is no change, well, it’s all fine. Unfortunately, what is not evident is that the energy waste cost is already in the current bill, as well as in the prior ones and in the ones that will follow.

Energy waste problems are not only due to equipment lack of maintenance or wear and tear, but also due to the lack of commissioning from the day they were installed. These inefficiencies carry over the entirety of the equipment or system’s lifespan and are very difficult to detect by someone who does not have in-depth knowledge and understanding of how these systems operate. We find these inefficiencies too frequently in HVAC systems in commercial facilities.

Building Energy Consumption Pattern

Although electric power consumption is a function of demand, there is a common pattern that can be identified and tracked in most buildings. This pattern can help building operators to predict and take measures to reduce power consumption, preemptively address possible failures, and avoid unnecessary energy waste.

The lack of an EMS prevents building operators from identifying developing energy inefficiencies and anomalies in power consumption patterns. As we mentioned, most buildings simply rely on their utility power bill to take reactive actions, which, more often than not, ends up being a very costly approach.

Why do most buildings lack an EMS?

It’s worth starting out by saying that commercial buildings normally have some kind of smart building infrastructure such as a Building Automation System (BAS) and a Building Management System (BMS). However, many people confuse these terms with an Energy Management System or EMS and, although they are related, they all have different purposes and specific functions within a building.

Buildings that were built more than 20 years ago normally have a BAS and BMS, but they lack an Energy Management System because by and large, software and hardware technologies were very expensive, so only a few organizations could afford to invest in building out that infrastructure.

As a result, few consultant engineers specified an EMS in the construction documents, something that has carried over till today. It’s very rare to find specifications for an EMS implementation in construction drawings, and it also makes sense; the new generation of engineers learned from the prior one, so they are not likely to specify or recommend things they have not done or seen before.

However, design specifications ultimately come from the building owner, engineers won’t specify anything that the building owner did not request. Therefore, the intent of implementing an EMS should be the owner’s decision and the earlier EMS specifications are incorporated into the design the better will be for the final product.

Energy Management System Implementation

Implementing an energy management system as part of the smart building infrastructure can unlock another level in building supervision, awareness, and efficiency.

The implementation of an EMS into the facilities management infrastructure provides valuable benefits, such as:

Building Power Consumption Pattern Visualization: Real-time power consumption of a building. This is very valuable and actionable data that operators can use to manage and adjust equipment operating schedules and setpoints to maximize savings.

System Power Distribution Visualization by End Use: Breakdown of the different systems’ power consumption and demand. This data provides building operators information about the main drivers of energy consumption in the building and therefore where to dedicate the most effort optimizing (e.g. HVAC and Lighting).

Power Pattern Anomalies Detection: Smart algorithms that notify operators of a change in performance in a specific equipment or system, which can help prevent possible equipment failures, business interruptions, and costly power bills.

Building Power Consumption Optimization: System control strategies that target maximizing energy efficiency and power consumption savings. The systems most prone to optimization are the HVAC and lighting system.

Improved Bottom Line: Energy savings in the range of 10% to 30% can be achieved through energy efficiency and optimization strategies. This can represent a significant amount of capital for businesses that want to improve their bottom line and grow.

Paths to Implement an Energy Management System

The cost of implementing an Energy Management System has significantly decreased in recent years. Advancements in software and hardware technologies have made EMS solutions much more affordable and available to most businesses. Similarly, emerging IoT technologies are positively contributing to this trend.

For existing buildings, the most cost-effective path is leveraging the BMS and BAS infrastructure to build an EMS interface on top of it. Integrating power meters, frequency drives, switchgears, and transfer switches into the BMS can provide all the data points necessary to build out the EMS user interface for operators to visualize power trends, energy benchmarks, and equipment efficiency metrics.

On the other hand, for new construction buildings, the most recommended path is to add EMS specifications in the early phases of design into the construction documents with the help of EMS consultants and MEP engineers. This ensures that the building design is conceived with the objective of providing an Energy Management Platform for future building operators.

Energy Management System Data

Energy management systems record, store, and process and display energy-related data for building operators’ supervision, optimization, and management.

For simple analysis, we can classify the energy data into three main categories:

Building Power Data: Electric power factors that make up the building power bill such as total building power consumption, peak power demand, and power factor. Another very important data point to track is real-time building demand.

Building Energy Benchmarking Data: Benchmarking serves as a mechanism to measure the energy performance of a single building relative to other similar buildings. Energy benchmarking includes the calculation of the building Energy Utilization Index (EUI) that refers to the amount of energy used per square foot annually, as well as the Energy Cost Index (ECI) of the building, expressed in dollars per square foot per year.

Equipment Efficiency Data: Manufacturers provide expected efficiency data on the equipment such as the Seasonal Energy Efficiency Ratio (SEER) in HVAC systems that compares equipment outputs versus power consumption. Similarly, we can estimate lighting efficiency by comparing the light source output (lumens) versus the power required to produce it.

Combining these data points into a user-friendly interface can paint a clear picture of the building energy patterns, as well as the equipment and system efficiency performance, forming what is a comprehensive building Energy Management System.

In Summary

Building Energy Management Systems (EMS) provide valuable energy-related data and information on the facilities’ energy use and efficiency performance. This data allows building owners and operators to make informed decisions to optimize systems and eliminate energy waste sources, unlocking unprecedented savings in energy consumption.