How switching to Ambient IoT can reduce your operational expenses and environmental impact? Let’s have a look at the true cost of replacing IoT device batteries.
Over 20 billion IoT devices are in operation today, with this number set to double during the next five years. In smart buildings and smart homes, these sensors and actuators are used to automate systems such as heating, security, air quality, lighting and energy management.
Depending on the type of facility, IoT devices will also be used for a host of other functions and the numbers of IoT devices implemented by a single organization can stretch into the thousands. For example, it was recently reported that the Dartford and Gravesham UK hospital trust, which is a mid-sized trust with only three sites, has implemented over 11,000 medical and facility automation IoT devices.
The majority of IoT systems are powered by batteries, which gives greater flexibility and ease of use. But with estimates that suggest many millions IoT batteries need to be replaced every day, there are two significant issues for organizations relating to their replacement:
- The operational expense of battery replacement (including the man hours needed to undertake this),
- The environmental impact of discarding chemical batteries.
In this blog we’ll look at how a switch to Ambient IoT devices, which use energy harvested from the environment, can reduce both of these and how to select such a system. In this, we’ve looked specifically at systems for smart buildings, for example in energy management, but the principles hold true across many other IoT systems too.
The need for energy harvesting
In a positioning paper, researchers from the European Union’s EnABLES project are urging developers of IoT devices to “ensure that batteries outlive the devices they power.”
In the paper, the researchers stress the need to harvest available energy from the environment to make batteries last longer, while also reducing IoT device energy consumption.
For smart building facility operators, the switch to the Ambient IoT would not only remove the cost of battery replacements, but also the staff costs related to monitoring the devices and replacing cells when required.
And while not suitable for all IoT applications, energy harvesting should provide enough for a wide variety of smart-building IoT sensors and actuators, including for security and energy management.
Of course, energy levels from harvested sources can vary throughout the day, and an energy storage device is therefore still needed in systems that need continuous operation. However, switching to the Ambient IoT will, in many cases, enable a switch from chemical batteries to supercapacitors. These are typically based on carbon-based materials, store energy electrostatically (not chemically), and have extended lifespans. They are also easier to recycle and will not leach chemicals into the soil if incorrectly disposed of.
IoT systems that can make the switch
A typical Ambient-IoT system for smart buildings – such as a thermostats, light sensors or air quality monitor – will be built around a sensor or actuator. They will be powered by an energy harvester connected to a power management chip (PMIC) and energy storage. A low-power processor will also be implemented, along with data transmission capabilities and a small number of other components.
The nature of smart building IoT devices, means these components have been developed to run autonomously on a single battery for several months or even years. Indeed, they have typically been optimized for ultra-low-power operation and tailored to a specific application.
This makes them exceptionally well suited to being powered from harvested energy, where power delivered is in the order of microwatts or milliwatts – and even several watts is possible.
Available energy sources
There are several energy sources – for example solar cells – that can be implemented to enable continuously operational systems. Additionally, there are also energy harvesters – for example kinetic switches – that are developed to generate a required energy level at the specific moment of use.
In smart-building Ambient IoT systems, solar (or photovoltaic) cells will enable continuous function in a wide range of systems and can be used under both natural and artificial lighting. Indeed, they’re the most-commonly used energy source for Ambient IoT systems, and can be used for smart-locks, leak detectors, CO2 sensors, humidity sensors and thermostats, as well occupancy sensors and other security systems.
Other sources include vibration transducers, for use on continuously moving systems, and thermoelectric generators, which can be used in environments with hot and cold zones that create a temperature gradient. Kinetic switches can also be used in smart light switches and similar applications that need to send small packets of data. In the case of a smart light switch, this might be to turn on/off, dim or set the colour.
Recent years have also seen the introduction of power management chips that can combine multiple energy sources. These can be used to either increase the power delivered to the IoT device or ensure greater flexibility when an energy source is less stable – for example running both a solar cell and a vibration transducer.
Where to begin your switch the Ambient IoT
The size of the Ambient IoT has grown significantly and a vast number of organizations are developing smart building systems (among other functions) for it.
This is enabling operators of these facilities – be it hospitals, councils, serviced office providers, etc – to cut the staffing expenses as well as the cost of the batteries themselves when implementing these devices.
Of course, there will be functions that demand custom systems developed and e-peas works with a large range of OEMs and technology developers who will be able to help.
e-peas is a leader in power management chips for energy harvesting-powered systems. Below is a list of organizations that will either have the technology you need, or will be able to help you develop an Ambient IoT system that costs less to run and reduces the environmental impact of your operations.
For further information on how to find an IoT application developer, please see our partner page.
