Compared to plug-in or battery-operated sensors, energy harvesting sensors offer multiple advantages. As manufacturers implement the Industrial Internet of Things, self-powered sensors become a key component. The benefits are immediate, and their impacts are felt through the entire sensing system. Remote monitoring specialist, DCO Systems, explains.
The main intention of equipment sensors is to harness accurate and continuous data. Many vendors claim their sensors possess extravagant battery lifetimes; however, batteries are finite energy sources. This means that to get long life, battery-powered sensors must do less. Set battery capacity means all design decisions are a zero-sum balance of capability versus consumption. Design decisions for sensors end up being made with extending battery life, not functionality. Simultaneously, radio transmissions are relatively energy-intensive, and common low-power techniques encounter limitations in industrial settings with interference, limited lines of sight and extended range. As a result, battery-operated sensors transmit data less frequently, providing timed snapshots or rather puzzle pieces of a process.
In contrast, energy harvesting creates the conditions for more frequent data reporting with the always-on, real-time connection of equipment and assets. Data is captured at the source, and sensors continuously transmit the data collected to cloud-based software. This allows engineers to access updates, diagnostics, and predictions wherever they are and whenever they want.
Energy harvesting sensors can adapt, measuring their harvesting and dynamically adjusting power use to suit the operational and reporting constraints set by their users. Furthermore, self-powered sensors also store extra energy, ensuring uninterrupted data reporting. With continuous monitoring, energy harvesting sensors move their users into a high-definition world.
Simplification and ease of use
To implement plug-in sensors, manufacturers are confronted with the immediate limitations of location and infrastructure. Either there are plug-in sources near the machine, or users will need to install wired power. Upfront costs for implementing plug-in sensors include contracting an external resource for electrical installation or using in-house resources with their opportunity costs. Ongoing costs include the energy usage from the number of sensors tapped into a power source, adding to the bottom line. Further constraints include restrictions on where power sources can be installed, dependent upon infrastructure and the safety hazards of additional wires within a plant.
Alternatively, energy harvesting sensors have a simple plug and play installation. They are easily and safely mounted to a machine – in any location. Energy harvesting sensors eliminate the need to install additional power sources and are ready to harness data immediately.
Battery-free and maintenance-free
All battery-operated sensors will need their batteries changed. This creates a time-consuming additional task for engineers to perform routine maintenance and battery exchanges. In comparison, battery-free, energy harvesting sensors do not need routine maintenance, and they work non-stop without battery changes. Combined with the simplicity of installation, self-powered sensors are an ideal choice for remote monitoring in hard to access locations and sites with limited existing infrastructure.
Impact on the environment
Wired sensors rely solely on an installed power source and use energy. Unless a plant is fully powered by renewable sources, the energy needed to run additional equipment will generate waste and add to carbon emissions. As for sensors that run on batteries, most of the waste is in the supply chain. There is an impact on the environment when batteries are produced, and used batteries are discarded.
Alternatively, energy harvesting sensors harness energy from their surrounding environment, something that is already there, and using it generates zero waste. Ambient energy exists naturally and includes heat, light, movement, and other sources. Energy harvesting sensors are vital for reducing a plant’s overall energy usage. Furthermore, there is no continuous environmental waste generated.
Sensors for specific applications are already available with extensive customisation possible through sensing, communications, and energy harvesting options. Equally important is that the customer can easily install all sensors. For example, DCO has evaluated installers’ practical needs and included coordinated connectors, adapters, and fittings for many different requirements, with installation videos that lend additional support if needed. The ease of installation and use means that these energy harvesting sensors can be up and running immediately.
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