This section outlines the main components of an energy management technology (metering, monitoring and control) system and the associated benefits.
Main components of an energy management technology system
Energy management technology systems involve both:
- Automatic systems, to meter and monitor energy and other parameters, and control energy-using equipment – These may be stand-alone systems, but are usually a capability integrated into a system with broader goals, such as manufacturing process control, building management and air-conditioning control. In manufacturing processes, automatic control systems are known as Supervisory Control and Data Acquisition (SCADA) systems. In commercial buildings, they are known as:
– Building Management Systems (BMS)
– Distributed Control Systems (DCS)
– Building Automation Systems (BAS)
– Building Energy Management Systems (BEMS).
- Human and organisational aspects of managing energy – This includes leadership, policies, target setting, management procedures, monitoring and reporting.
The main components of an energy management technology system are:
- energy inputs from various metering devices, e.g. for electrical energy, gas volume, thermal energy
- other inputs, which can be switches, momentary buttons or sensors (e.g. temperature, humidity, flow rate, pressure, position, occupancy)
- outputs to devices which are controlled, such as switches and motor contactors, dampers, valves, control signals, solenoids and alarms
- the controller, comprising a computer or micro-processor, program and data storage, clock and calendar
- at least one user interface, which is normally a computer terminal but could be a simple device with a few lines of display and a few buttons
- a communications network to connect the inputs, outputs, controller and user interface.
Older automatic controls typically respond to only one or two inputs, and use simple control logic. They use a separate controller for each function, and there are no connections among the various controllers. Each control or sensor connection requires a separate power or communication cable. By comparison, modern and integrated control systems can:
- control according to multiple inputs such as sensors, time of day, data from external systems, buttons and other human interfaces
- control according to complex logic
- monitor and log the value of inputs including data from energy meters
- analyse and report on performance including energy consumption
- communicate multiple data types, signals and commands over a single cable or wireless connection
- communicate information over the internet, and/or local and wide-area networks, making information accessible to more people to influence energy performance.
For more information
- Energy Efficiency Opportunities (EEO) Assessment Handbook 2011 (Opens in a new window)
This guide was developed as part of the EEO Program and provides examples and guidance for conducting a rigorous energy efficiency assessment. It includes techniques to use energy data to aid understanding of energy usage as well as guidance on investing in sub-metering.
- Department of Industry
Benefits of energy metering and monitoring
Benchmarking energy usage
Energy metering and monitoring enables benchmarking of current energy usage and comparisons across different locations, e.g. sites and transport fleets. It also enables comparisons between a company’s energy performance and figures from design calculations as well as theoretical best practice. This can assist the quantification of the potential for energy efficiency improvement.
Excerpt from the EEO Assessment Handbook:
Benchmarking actual performance against design calculations can provide a basis for identifying deviations from design resulting from poor installation, commissioning or maintenance, or from faults, or as a result of operation in ways different from those envisaged by the designer.
Benchmarking against theoretical ideal performance helps to identify where waste is occurring. This approach often facilitates radical changes that may lead to dramatic efficiency improvements through adoption of alternative approaches. This approach identifies ‘stretch’ targets and also encourages analysts to track down where all the energy has been lost.
For more information
Energy usage analysis and efficiency opportunity identification
Data on energy consumption, and the variables which influence it, can be used to identify energy efficiency opportunities and assist with the quantification of those opportunities for preparing business cases.
Metering and monitoring can be broken down to pinpoint energy consumption according to the areas of a building or factory, the major energy using processes, and usage during specified time frames. These breakdowns of information enable staff to focus on the areas with the highest energy use and the best energy savings potential. Reporting energy used in shorter time periods can provide insights not available from monthly billing data. For example, weekly data might reveal the effect of different shift teams’ operating procedures, and daily data could reveal excess energy use on weekends. Real-time data allows evaluation of equipment performance and identification of the causes of demand peaks.
For more information
- Energy Savings Measurement Guide 2013 (Opens in a new window)
- Department of Industry
This guide provides detailed and best practice guidance on how to estimate, measure, evaluate and track energy efficiency opportunities. It provides in-depth information on capturing energy data, establishing an energy baseline, developing an energy mass balance, analysing potential energy efficiency opportunities and monitoring the performance of implemented energy efficiency initiatives. The resource was developed for large energy-using organisations, but the tools can be applied across multiple sectors and organisation sizes.
Improved control complements the installation of more flexible plant equipment, such as variable speed motor drives and variable heat sources, by allowing them to be operated optimally. The demands on most energy-using systems vary according to factors such as weather, time of day, production volumes, product mix, feedstock characteristics, building occupancy, etc.
An energy management technology system can improve control accuracy (higher production yield, more consistent product quality, better comfort) by controlling energy-using equipment according to system demands. The process control can reduce the energy consumption so it is closer to the theoretical minimum energy required under given operating conditions than is possible with simpler controls.
Energy consumption data feedback can also be used to improve control and refine algorithms. The improved control can safeguard equipment and help to manage assets and reduce the need for maintenance. Energy control systems are well suited to applications where:
- Sophisticated control is required – Optimal control of systems to minimise energy consumption or achieve accurate process control requires sophisticated logic or algorithms and/or multiple inputs. For example, outside air dampers might be controlled according to time of day, air quality (CO2, mixed gas, or VOC sensor), demand for cooling, return air temperature/enthalpy, outside temperature/enthalpy, and whether in warm-up mode or not. A production process might be controlled according to feedstock moisture content, ambient temperature, extracted air relative humidity and the requirements of a particular product type.
- Requirements change frequently – Under rapidly changing conditions, an energy management technology system is likely to save time and effort, and facilitate the development of programs to suit multiple situations. Examples of frequently changing requirements include flexible manufacturing, production processes that adjust to variations in raw materials and ambient conditions, universities with changing timetables and occupancy, and hotels and function centres.
- Energy-using equipment, sensors and controllers are dispersed and numerous – The communications protocol of an energy management technology system allows multiple data and controls to be communicated over a single bus (e.g. a pair of wires or even a wireless channel) and so reduces the cost and complexity of connecting numerous and dispersed sensors and controlled devices. A single sensor for ambient temperature, for example, can be used in the control logic for many devices, rather than needing multiple sensors.
Makes energy consumption visible and assists with reporting
An energy metering and monitoring system can consolidate information from electricity and gas billing meters and the company’s own meters (electricity, gas and possibly thermal), and report that information in a clear, user-friendly format. Making energy consumption visible in this way helps to identify where energy efficiency improvements can be made.
Quantifying energy use can also help to minimise peak demand usage. If the energy control system monitors electricity or gas demand and the retail or network tariff includes a demand cost component, it is possible to determine if any loads can be controlled to limit the demand. Methods of control can include duty cycling, load modulation or limiting the amount of energy-using equipment that operates simultaneously. This control may also include smart load shifting and shed/restore load techniques.
Making energy use more visible also provides early warning of efficiency deterioration and reveals any equipment running when not required. Another advantage is positive reinforcement when savings are achieved.