IoT for Smart Energy Sub-Metering Plan: A Guide for Better Consumption Control
- What is an energy sub-metering plan?
- Advantages of an energy sub-metering plan: Towards managing energy expenses
- How to develop an energy sub-metering plan for your buildings?
- Why Traditional Energy Management is No Longer Enough
- How an IoT Energy Management System Works
- Wattsense: The Connectivity Backbone for Your EMS
The global drive toward sustainability and the rising cost of utilities have placed energy performance at the top of the agenda for property owners and facility managers. Traditional methods of monitoring energy usage are no longer sufficient to meet the demands of modern portfolios. The solution lies in the deployment of a robust iot energy management system and a sub-metering plan.
An IoT energy management system represents a paradigm shift in how we interact with the built environment. By leveraging the Internet of Things (IoT), buildings are transformed from static structures into intelligent, data-driven assets. This technology allows for the centralisation of disparate data streams, providing the transparency required to improve building performance, meet stringent environmental regulations, and significantly reduce operational costs.
Are you aiming to efficiently manage your energy consumption and cut down on costs? If you're finding it challenging to organize your efforts, an energy sub-metering plan could be the solution to structure your approach. What exactly does it entail, and why is it important to implement? What tangible benefits can you anticipate? Explore, step by step, how to roll out an energy sub-metering plan and make well-informed decisions about investments.
What is an energy sub-metering plan?
An energy sub-metering plan is part of an initiative to enhance the performance of one or more buildings. However, it extends beyond merely measuring energy consumption. It serves as a strategic tool that provides a comprehensive insight into the utilization of energy within a building.
The primary stages of an energy sub-metering plan include:
- Measurement
- Data collection
- Analysis
- Optimization
By strategically deploying sub-meters and sensors, this plan offers a detailed analysis of various consumption points. It enables the identification of energy-intensive behaviours/actions or instances of resource wastage.
To sum up, an energy sub-metering plan aims to address the following questions:
- How is energy currently being utilized?
- Is the current energy consumption of my building justified?
- What areas can be improved?
- How can I reduce my energy expenses while maintaining or increasing performance and productivity levels?
- How can I sufficiently decrease energy consumption to meet regulatory obligations?
An important clarification: an energy sub-metering plan doesn't solely collect consumption-related data. It also integrates other specifics about the building and its activities to determine an overall performance level.
Read: Understanding the Energy Management System (EMS)
Advantages of an energy sub-metering plan: Towards managing energy expenses
The benefits are numerous, but the primary advantage of an energy sub-metering plan lies in understanding how your building operates, structuring improvement actions, and sustaining your gains:
- Identifying wastage and energy inefficiencies
- Pinpointing energy-intensive areas: prioritize actions on zones contributing the most to energy costs
- Highlighting consumption trends: adjust daily operations and/or anticipate peak periods
- Making informed investment plans: target and schedule improvement actions in order of priority, supported by numerical data
- Justifying a continuous improvement approach within ISO 50001 certification parameters
- Supporting reductions in consumption in compliance with government regulations.
How to develop an energy sub-metering plan for your buildings?
1) Initial assessment:
The first step in implementing a metering plan is to establish an initial assessment as accurately as possible. The goal is to understand how much your building consumes, what it produces, and how it operates (number of employees, opening/production hours).
This assessment is based on the information available before the implementation of the metering plan. At this stage, no sub-meters or sensors may be installed. In this case, gather all possible information: energy bills, production reports or revenue tables, external conditions, changes in workforce, periods of closure, etc.
The initial assessment provides an initial overview of the distribution of consumption and energy costs. If sub-meters are already installed, it's possible to detail consumption according to usage.
Conducting an energy audit is recommended to provide a comprehensive picture of your facility. It officially describes the performance and condition of your building before any improvement actions.
2) Identifying parameters to study
Building operation conditions
Based on the initial assessment, it's important to identify various parameters that influence your consumption. Here are some examples:
- Operating/opening hours
- External temperature
- Sunlight exposure
- Company workforce
- Efficiency of used appliances
Once identified, priority influencing factors can be modified (where possible) to accurately assess their impacts. This may require the implementation of value sensors or monitoring procedures.
Energy Performance Index (EPI)
The Energy Performance Index (EPI) describes the relationship between energy consumption and a given influencing factor. For example, you can compare your electricity consumption with your net profits or production volume (in the industrial sector). In this scenario, a decreasing EPI means that with equivalent or higher production, your consumption decreases, making your site more efficient.
During this stage, you'll also need to define the goals of your improvement process. Subsequently, you can deduce the most relevant EPIs to regularly study. Do you want to reduce operating costs, achieve regulatory compliance, or both? Do you have a specific target to reach, or do you simply want to reduce your environmental impact?
3) Selection of suitable measurement points and technologies:
The next step involves determining the technical means required to regularly calculate the performance indices you've chosen.
What data do you need to measure? In which areas? Through what means? At what frequency? These data will be of two types:
- Energy consumption, through sub-metering
- Values or quantities of influencing factors, via sensor installation or administrative tracking
The energy monitoring plan serves as a planning tool as well as a guide for locating installed measurement equipment. To identify areas for improvement, you must first be able to precisely measure numerous parameters over a significant study period. Gathering this information inevitably involves the installation of sub-meters (water, electricity, gas) and sensors that need to be accurately identified.
For each identified need, the energy monitoring plan specifies the measurement equipment used, its physical location, and the chosen communication protocol for data collection. Each piece of equipment is uniquely identified.
Did you know that communicating sub-meters are equipped with features that allow the automatic transmission of collected information? They thereby eliminate the need for manual meter readings.
4) Data collection and analysis
The measurements conducted as part of an energy monitoring plan allow you to analyze your site's energy usage over a significant period. The variation in influencing factors will help highlight potential energy savings.
For maximum efficiency, the process of retrieving measurements and the chosen analysis tools should be as straightforward as possible.
If you opt for an Energy Management System (EMS) software to collect and analyze your results, make sure to choose an intuitive solution that provides "visual" information: graphs, distribution diagrams, etc. Raw data from your measurement points will then be converted into a readable result, making it easier for decision-makers to utilize and understand.
Installing a Building Management System (BMS) associated with an EMS helps facilitate data retrieval and analysis. These connected solutions increase the frequency of readings (real-time monitoring without mandatory human presence) and maintain a history of values for a better understanding of the site. You also have the option to analyze a multitude of measurement points for a comprehensive study: a task that is difficult to achieve "manually."
The Wattsense Tower easily connects to all the equipment on your site, whether already in place or added later. It simplifies the deployment of your energy monitoring plan by collecting and centralizing data from all your measurement points. Visualize your data as bar graphs or diagrams on the Wattsense console, designed to offer optimal readability.
Our advice: Connected solutions like a BMS greatly facilitate the implementation of an energy monitoring plan. However, depending on the condition of your building or the age of your equipment, installing such a system may come later, after investing in more "urgent" energy actions. Although not a priority at the start of your initiative, it can represent an optimization opportunity in your continuous improvement process.
Thanks to the Wattsense solution, Cyrisea has deployed efficient electricity and DHW (domestic hot water) metering plans in collective housing units to ensure a fair distribution of rental charges and avoid any energy drift.
5) Implementation of actions and continuous improvement
The targeted implementation of improvement actions (and their execution) is the ultimate goal of an energy monitoring plan.
For instance, analyzing sub-metered consumption can highlight energy-intensive equipment or "phantom" consumption during off-hours. Observing consumption trends based on your company's strategic cycles may lead you to slightly adjust operating hours or consolidate certain tasks.
Priority improvement actions are those with the most significant impact on reducing your energy expenses, allowing you to decrease the previously chosen Performance Indices (PIs).
Note: Implementing an energy monitoring plan is not a one-time endeavour that concludes once actions are implemented. It's an iterative process that takes time and is part of a continuous improvement approach.
When a new action is integrated into your operations, a new study cycle begins to measure its actual gains. New improvement avenues are then suggested, leading to the implementation of further adjustments, which are themselves studied, and so on.
Why Traditional Energy Management is No Longer Enough
For decades, buildings relied on basic utility meters and closed-loop Building Management Systems (BMS). While these tools provided foundational control, they often lacked the flexibility and granularity needed for true energy efficiency. In today’s high-cost environment, "good enough" is no longer an option.
The Limitations of Legacy BMS and Siloed Data
Traditional systems are frequently built on proprietary architectures that do not communicate well with external software or other hardware brands. This results in siloed data, where information from the heating system is trapped in one interface, while electrical data sits in another.
Without a unified view, facility managers struggle to identify the root causes of energy waste. Legacy systems often provide a "macro" view of the building, which hides "micro" inefficiencies. An iot energy management system breaks down these silos, acting as a universal translator that brings all building data into a single, actionable stream.
The Rising Demand for Granular Data and Sub-Metering
Relying on a single main meter for a large commercial facility provides very little insight into where energy is actually being consumed. To drive real energy efficiency, managers require sub-metering.
Sub-metering involves installing individual meters on specific subsystems—such as HVAC, lighting, or individual tenant floors. This granular data allows for:
- Tenant Billing: Accurately charging occupants based on actual consumption.
- Waste Identification: Spotting equipment that runs unnecessarily during unoccupied hours.
- Operational Benchmarking: Comparing the performance of different zones or buildings within a portfolio.
Meeting Regulatory Standards and ESG Goals in the UK
In the UK, the regulatory landscape is shifting rapidly. Frameworks such as the Streamlined Energy and Carbon Reporting (SECR) and the Energy Savings Opportunity Scheme (ESOS) require large organisations to provide detailed accounts of their carbon footprint.
Furthermore, investors are increasingly prioritising Environmental, Social, and Governance (ESG) goals. A building that cannot demonstrate a high level of smart energy management risks becoming a "stranded asset"—losing market value due to its environmental inefficiency. Implementing an iot energy management system is the most effective way to automate compliance and prove sustainability commitments to stakeholders.
How an IoT Energy Management System Works
Unlike traditional setups, an IoT-driven approach focuses on connectivity and interoperability. It creates a digital nervous system that extends from the basement boiler room to the cloud-based analytics platform.
Architecture: From Sensors to Cloud Analytics
The architecture of a modern iot energy management system typically follows a three-tier structure:
- The Device Layer: This consists of smart meters, IoT sensors (measuring CO2, temperature, occupancy), and technical equipment like HVAC controllers.
- The Connectivity Layer (The Gateway): This is the heart of the system. An IoT gateway collects data from the device layer, normalises it, and pushes it to the management software.
- The Application Layer: This is where the data is processed. Cloud-based energy management software (EMS) provides the dashboards, alerts, and historical reports that drive decision-making.
The Role of Connectivity Protocols (LoRaWAN, M-Bus, Modbus)
To achieve true interoperability, the system must support a wide range of technical languages. In the context of energy monitoring, three protocols are particularly critical:
- Modbus: The standard for most power meters and heavy electrical equipment.
- M-Bus: Designed specifically for the remote reading of utility meters (water, gas, heat).
- LoRaWAN: A long-range, low-power wireless protocol. LoRaWAN is the gold standard for sub-metering and environmental sensing because it can penetrate thick building walls without the need for expensive cabling.
- BACnet & MQTT: Protocols used to integrate with existing BMS and push data to cloud platforms.
Real-time Monitoring vs. Historical Data Analysis
A sophisticated iot energy management system provides two types of value. First, real-time monitoring allows for immediate action. For example, if energy consumption spikes unexpectedly, the system can trigger an automated alert, allowing a technician to investigate before the waste accumulates.
Second, historical data analysis enables long-term building performance optimisation. By looking at months of data, managers can identify seasonal trends, verify the ROI of retrofit projects, and perform predictive maintenance on assets that show signs of declining efficiency.
Wattsense: The Connectivity Backbone for Your EMS
Wattsense provides the technology to simplify building management. We remove the technical barriers that often prevent an iot energy management system from functioning effectively. Our mission is to help you collect and centralise data, improve building performance, and save time.
By acting as a universal interoperability hub, Wattsense connects any building equipment to the tools of your choice. We offer three solutions tailored to different building management needs.
Wattsense Bridge: Unifying On-Site Protocols for Local Control
The Wattsense Bridge is our foundational solution for local data acquisition and on-site supervision. It is the most innovative open, interoperable IoT gateway on the market. It is designed for distributors and integrators who need a reliable link between building equipment and an on-site supervisor or BMS.
Key features include:
- Remote Configuration: Manage your gateway settings from anywhere via a cloud console.
- Real-time Data: Access immediate insights for local automation.
- Local Redirection: Easily integrate with BACnet, Modbus, or MQTT.
- Ideal for: Projects where you need to integrate LoRaWAN sensor data into an existing BMS to enable local automation based on real-time conditions.
Tower Lift: Sending Reliable Data to Energy Management Software (PropTech)
Tower Lift is the IoT solution specifically designed for PropTech companies and large-scale asset managers. It focuses purely on efficient and secure data retrieval, providing powerful cloud connectivity.
For an iot energy management system to be effective at scale, it needs reliable data delivery. Tower Lift provides:
- Data Historisation: Store and access historical data for in-depth analysis.
- API & Webhook Integration: Seamlessly push data to your preferred cloud platforms and energy management software.
- Scalability: Perfect for residential or commercial portfolios where the primary need is to collect vast amounts of data (e.g., electricity, water meters) via API for billing or energy performance apps.
Tower Control: Automating Efficiency in Small-to-Medium Buildings
For small and medium-sized commercial buildings—such as retail stores or post offices—a full-scale BMS is often too expensive and complex. Tower Control is our "Light BMS" solution, providing a complete automation suite that puts you in command.
With Tower Control, you can take total control of your iot energy management system:
- Automation Scenarios: Create rules to optimize energy consumption (e.g., dimming lights based on occupancy).
- Scheduling: Implement time-based controls for HVAC to ensure energy is only used when the building is occupied.
- Remote Alarms: Receive instant notifications for critical events, such as a boiler lockout or an energy spike.
Visual Dashboards: Monitor building performance in real-time through intuitive, customizable graphs.
Interested in deploying an energy monitoring plan at your site? With its easy installation and universality, the Wattsense Tower can streamline your process. Connect all your equipment in just a few clicks and access all your data in real time. Request your personalized demo to learn more.
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