As energy prices climb and legislative and regulatory focus on energy consumption increases, building owners and managers are turning to new technologies to assist them in energy management.
Building energy management systems (BEMS) provide a highly adaptive solution for the ongoing refinement of building energy management. These systems use several emerging technologies for the remote monitoring of building energy performance and precision control of consumption.
In this article, we explain what building energy management systems are, how they work, and the benefits and limitations of implementing this technology in residential and commercial buildings.
What is a building energy management system?
Building energy management systems, or BEMS, are a diverse group of technologies that monitor and control the energy consumption of a building. They combine automation, the Internet of Things (IoT), machine learning, and artificial intelligence (AI) to precisely manage energy use by building appliances, lighting, and HVAC.
BEMS are distinct from building management systems (BMS) which are computer-based systems that integrate the functions of an entire building including, fire protection and security. BEMS are available as custom, programmable, or pre-programmed solutions.
Building energy management systems provide buildings and facilities managers with a tool for improving the energy efficiency of the properties they manage.
The IT systems that run BEMS gather data from a range of control and automation inputs. The following are example data sources used to optimize the use of energy with building-wide automated and manual improvements:
- traditional control and automation systems
- smart meters
- consumption data
- advanced sensors
- utility price tracking
- wholesale energy prices
- business intelligence
How do building energy management systems work?
BEMS are a type of building automation system (BAS) that monitors and controls the individual mechanical devices and appliances that consume energy in the building.
A competent BEMS requires:
- A distributed network of sensors for parameters like temperature, light, humidity, and movement.
- Automated or remotely controlled actuators for pumps, vents, windows, radiator valves, thermostats, power switches, and light switches.
- A controller that receives inputs from the sensors and coordinates output instructions to actuators. The controller may be automated or a building manager can control it in real time.
The system uses its sensors and actuators to control and optimize conditions within the building, adapting to the use and demand of its occupants. For example, a BEMS can actively maintain a comfortable internal temperature by switching furnaces on or off, closing windows or adjusting radiator valves.
However, BEMS are distinct from standard thermostat-based heating control as it is much more hierarchical and delivers precision control that is integrated with other energy consumption.
Description of building energy management systems
The functionality of building energy management systems spans four key areas:
1. Visualization and reporting
Building energy management systems provide facilities managers with a software interface, for interacting with the system. The software element of a BEMS presents detailed reporting on the status and consumption of the building’s appliances and heating. Information relating to the BEMS is visually displayed, using dashboarding, charts, and graphs.
2. Fault detection and diagnostics (FDD)
Fault detection and diagnostics is a critical aspect of the management of buildings involving the identification of errors in the physical systems that operate in the building. By uncovering these faults and errors promptly, managers can remedy them before there is a derangement of energy resources, a change in building conditions, or failure of the system.
3. Predictive maintenance
Predictive maintenance uses IoT sensors and other condition monitoring tools to monitor the building energy systems. This technology can alert managers when maintenance is needed. By monitoring the performance of the energy systems and appliances in the building BEMS can ensure that appliances are properly maintained so they don’t use excessive energy.
4. Continuous improvement
A BEMS uses its data feeds and sensor input to look for opportunities to improve energy efficiency. The software algorithms and machine learning of the BEMS determine the parameters for implementing improvements to the building’s energy consumption, optimizing its performance.
Any building can be a smart building
BEMS can be implemented in any type of building including residential housing blocks, commercial buildings like supermarkets, offices, malls, or industrial sites where the BAS microprocessor technology was first used in the 1970s.
Factors to consider before installing a BEMS
The energy consumption needs of different buildings vary widely. This means that the specifications and functionality of BEMS have to be tailored to an individual building’s needs.
Here are some of the key factors that can help you determine the best type of BEMS for a building:
Building size is one of the most important factors for determining what caliber of BEMS is required. Large buildings, understandably, have greater energy demands than small residential dwellings.
For a larger building, rather than using consumer ‘smart home’ solutions and billing analysis, building owners and managers build custom BEMS that include features like advanced and predictive analytics, demand response, building optimization and automated building controls.
The region the building is located contributes climatic factors that affect the energy demands of the building. In places where there is strong seasonality or temperature extremes, a BEMS can learn and manage consumption for the external temperature highs and lows to maintain a comfortable and consistent internal environment.
The number of buildings that need to be managed
It is hard to implement a harmonized BEMS for multiple buildings. Even identical buildings often have unique characteristics and performance nuances, making the implementation of a single BEMS difficult. This means that each building within an estate will require its own BEMS.
The building’s use determines the level and pattern of occupancy. The system that is used has to respond to the type of occupant, for example, office workers versus residents. BEMS specifically monitor and support occupant comfort, especially if they make adjustments to thermostats or air conditioning.
The benefits of building energy management systems
Building energy management systems herald a new age of smart buildings that managers can optimize for maximum energy efficiency, with equipment and appliances carefully controlled. These energy management systems deliver wide-ranging benefits to building owners, facilities managers, contractors, and building occupants.
Here are some of the benefits BEMS deliver:
1. Building energy management systems deliver excellent ROI
Property owners and developers who invest in BEMS benefit from their in-built energy and cost-saving functionality. These systems continually work to reduce peak power consumption and optimize the energy efficiency of the building by adapting to actual occupancy and demand. Savings in utility costs quickly offset the capital expense of installing the system.
BEMS that offer the highest level of customization to the building use and energy requirements give building owners and managers the most control. The more sophisticated the BEMS, the greater the control of energy consumption and potential energy savings it can achieve.
2. A BEMS enables the energy consumption of a building to be controlled
The energy data and diagnostic tools of BEMS can optimize a building’s energy use and curb wastage. Building energy management systems monitor patterns in the demand and usage of energy in a building for precision control of energy consumption. According to Honeywell Building Technology, a BEMS can deliver control of up to 84% of building energy consumption.
3. BEMS reduces energy costs
The continuous improvement and optimization that BEMS minimizes energy wastage, saving money on utilities. A BEMS can achieve energy cost savings of up to 55%, because of the level of fine control the system delivers. These savings have a positive impact on the operating costs of the building or facility.
4. BEMS conserve energy
BEMS are one of the most effective ways for buildings to conserve energy. The potential for energy savings are noteworthy, especially when up to 80% of energy consumption is for heating and hot water in residential and commercial buildings.
Improved energy management provided by a BEMS can offset thermal losses from older buildings. The active monitoring and control of a BEMS means that energy use matches occupant requirements and habits.
5. BEMS can integrate renewable energy solutions
The responsiveness of BEMS enables them to integrate renewable energy sources like solar energy, which do not give continual power. Developers can readily integrate solar energy management systems with the software platforms of the leading BEMS solutions to ensure that any renewable energy generated by the building is utilized for maximum cost savings or profit, if added to the grid.
BEMS can also integrate demand-response (DR) solutions that enable building operators to take advantage of renewables to manage and reduce their demand for peak hours electricity from the grid. Many BEMS software programs provide the interfaces for in-depth renewable energy integrations like DR.
6. BEMS are designed to be adaptable
The machine learning and artificial intelligence technologies that the leading BEMS use enable them to adapt a building’s energy consumption to the needs of the building occupants. These systems respond to changes in occupancy, seasons, appliance, and device consumption and integrating new systems and products to maintain optimized energy management at all times.
7. Can aid building compliance
Energy management of buildings is a political issue and many governments are producing regulatory guidance or legislation for improving the energy efficiency of properties.
As a type of energy management system (EnMS), BEMS can help a building obtain key certifications like the U.S. National Energy Performance Rating System and ENERGY STAR Building Certification Program or ISO 50001 that specifically deal with energy management.
8. BEMS use time-saving automation
BEMS are integrated with a variety of automation technologies to reduce the physical workload of running a building. Aside from running HVAC, a BEMS can oversee lighting, windows and invent integrated fire protection and access control. This reduces the human resources required for building maintenance and management.
9. Building energy management systems help to reduce greenhouse gas emissions
Building energy management systems control the consumption of all energy sources used by the building, including electricity, natural gas, and heating oil. These systems can switch to energy sources that do not directly release CO2 like electricity rather than fossil fuels. By optimizing consumption the International Energy Agency suggests that there is an annual abatement of 1 GtCO2.
10. BEMS prolongs the longevity of HVAC equipment and appliances
BEMS facilitate better management optimization and maintenance of HVAC equipment, prolonging its usable life. Because the use of HVAC is more precisely controlled, preventing the overwork of parts like fans and pumps that can rest as much as possible.
This keeps resources in use for as long as possible without the expense of premature replacement.
11. Building energy management systems can reduce maintenance requirements
Equipment maintenance is expensive and requires manpower. A BEMS can help reduce the need for routine and unexpected maintenance by remotely monitoring the performance of HVAC equipment, alerting building managers when their function becomes abnormal, or breaches a critical number of usage hours, for timely repairs.
12. BEMS safeguard business continuity
Corporate, industrial and healthcare facilities that cannot afford to have downtime can benefit from robust energy management that may even have to include backup sources of power. The close monitoring of energy sources and power systems by a BEMS means managers can detect and remedy problem before a critical incident causes downtime.
Facilities managers can program BEMS software with alerts for specific problems that they can receive remotely. Developers can also configure BEMS to support the Service Level Agreement (SLA) of companies like web hosts or cloud computing service providers.
13. BEMS can improve the comfort of building users or residents
BEMS facilitate environmental conditions within the building that keep its users or residents comfortable. They can accommodate individuals changing heating or cooling settings, or the use of devices that use more power. These adaptive systems are always learning how to best manage user demand to optimize the well-being of building occupants.
Limitations of building energy management systems
Like many technologies, BEMS have their limitations, which need to be understood to implement building energy management that delivers results. This technology has been embraced in many parts of the world and sensor-based IoT technology is becoming more and more accessible. However, this technology is still relatively nascent and may not always be able to achieve the building intelligence that is envisioned.
Here are some notable disadvantages of BEMS technology:
1. Data inputs can be extremely dense
The sheer volume of data that is generated by the distributed IoT sensors and other inputs can be too unwieldy to extract and visualize effectively. The software that processes and analyses this data must be sophisticated enough to use it in a ‘smart’ way, changing how energy is consumed.
2. Setting up a building energy management system is expensive
Significant capital investment is necessary to install the data acquisition infrastructure and to implement specific solutions for key areas of energy consumption such as lighting. Costs for a BEMS can range between $2.50 and $7 per square foot, with the IoT equipment, (particularly custom actuators), being a major expenditure.
3. Skilled labor may be required to analyze BEMS data
Building energy management systems require skilled building managers or building engineers who can analyze and act on the data that a BEMS collects and processes.
These professionals understand the software and can adjust configurations and set points to optimize consumption. However, this skill set is beyond an ordinary facilities manager role and commands a higher salary.
4. If the configuration is poor, a BEMS may not deliver value
BEMS technology delivers energy and cost savings through its advanced configuration. Even with the best data collection infrastructure, a BEMS will not deliver value without being correctly configured; set points and schedules so that it can implement any required optimizations.
The configuration of BEMS requires specialist contractors, who can optimize a poorly deployed and configured BEMS to improve savings. Buildings and businesses like hotels, stadia, or malls that have a wide range in occupancy benefit from the skilled configuration that can learn trends and take advantage of periods of reduced demand.
5. Energy management in a building may already be well optimized
Some buildings may already be extremely energy efficient with consistent schedules and performance that makes a BEMS redundant. Some offices and residential apartments have such consistent schedules and occupancy rates that their energy management is almost completely optimized already and BEMS will add few changes.
6. BEMS may miss energy consumption from small equipment and appliances
BEMS software tracks patterning in energy consumption, rather than the use of individual devices. These systems can miss small equipment like electronics because their load may not be large enough to trigger sensors.
Also, BEMS may not control smaller equipment that may be part of the building infrastructure as it is configured to focus on the building systems that impact operating expenses most.
7. BEMS malfunctions may impact occupant comfort
An obvious problem can arise if the BEMS activates the settings for winter during the summer months and vice versa. If the BEMS functions separately to the general building monitoring, problems like fan and lift breakdowns may be missed. This is why building managers desire highly integrated solutions that give them oversight of condition in the entire building.
8. BEMS are difficult to scale across multiple properties
BEMS cannot be used to run multiple buildings within a property portfolio. Each building requires its own BEMS infrastructure, data protocol, processes and integrations, according to its amenities, appliances, and building conditions. Coordinating multiple sites on a single BEMS would soon become unwieldy and few software vendors offer this service.
9. A building can maintain energy management certifications without a BEMS
Building owners and managers can get energy certifications like the ISO 50001 for building without the expense of installing a BEMS. Facilities managers can implement the best practices for energy management outlined in many certifications by using low or even no-cost initiatives. A BEMS can then be introduced further down the line once the building has realized the initial energy savings.
10. Building energy management systems carry an inherent cybersecurity risk
By using cloud-computing software to manage the energy consumption of a building, owners introduce the real risk that someone may hack their BEMS. The data generated by the BEMS is valuable and may expose the building occupants to risks if accessed by malicious agents. An attack on the BEMS may also lead to downtime of essential services within a building.
BEMS can impact the energy consumption and ongoing maintenance of a wide range of building types. When installed and configured properly, they can help building and facilities managers optimize the energy performance of a property while providing a comfortable environment for building occupants.
However, the lack of scalability, scope, and high costs still hamper the widespread adoption of this technology. Smart buildings are definitely the future but BEMS still need work to play a part in the next phase of energy management.