How To Power IoT Devices
In this article, we will be diving into all things to do with power to answer the fundamental question – How to power IoT devices? We will be discussing where to start, key power management considerations, the options available to you based on the power consumption of IoT devices and to wrap things up we will share case studies for each option.
How To Power IoT Devices
In a world where digital technology reigns supreme, IoT has rapidly become an integral character in our lives and unleashed an entirely new way of solving problems and generating value. IoT’s impact on industry has been so transformational that it has given rise to what has now been coined the fourth industrial revolution (industry 4.0), aka the industrial internet of things (IIoT).
These devices, when properly configured, derive meaningful information that has fundamentally altered how our businesses operate. Companies such as Google, Amazon and even Disney Land have integrated IoT into their businesses to unlock latent value and improve their processes.
However, despite IoT providing almost unlimited opportunity to solve some of our worlds most significant problems, one of the most limiting factors in its usage is keeping its devices powered in the field.
So what are the options available to me and my team to keep my devices running and producing value? Read on to find out.
What you will get from this article
- Where to start
- How to measure power consumption of IoT devices
- The four most common power supply options for your IoT devices
- Defining the right supply for you
- Case studies
Where to start
The fundamental starting point for utilising IoT in the field is determining the power consumption of IoT devices you wish to deploy. Whilst IoT can do everything from logging water quality in a dam once per day to providing live stream video footage for artificial intelligence models, the methods of power supply required to run these operations are vastly different.
For instance, continuing from the example above, a basic IoT system using an Arduino to log water quality once per day in a remote location can comfortably run on a small battery topped up by a small solar panel for multiple years. This is because the device is only required for a split second each day to log a tiny data packet and can be programmed to ‘sleep’ for the remaining 23hrs 59min of the day until it is needed again.
However, the same cannot be said for video imaging. Video is far more energy-intensive and requires a more powerful controller such as a raspberry pi to capture, process and communicate the data to a database. The resulting data packet is far larger than that of a water quality reading and thus requires a more powerful and consistent power supply. Therefore, the video application would not be a good candidate for remote locations with no direct 240v power sources.
Is it impossible? No. Nothing is impossible in this space, and there are definitely workarounds, but this is what we must consider when balancing functionality and power.
How to measure power consumption of IoT devices
When it comes to deciding on the right power supply for your project, the first step is to analyse the power consumption of the devices you wish to deploy.
The most efficient and accurate way to assess this is to utilise power analyser tools such as the Otii which enable you to get accurate readings on power consumption. (I promise we do not have any affiliations with Otii, we just think it is a great tool).
Once you hook up your device to the power analyser of your choice and connect it to your desktop, you will get a graph reading like the one below. If you are unsure how to hook up your device to your power analyser, the maker of your model should have documentation on their website on how to do so.
With the power analyser we can determine the current (bottom) and the voltage (top), which we multiply together to get the power (watts) consumption. As you can see in the above image we have periodic spikes of power which indicate when the device is awake and transmitting information. A closer examination of these spikes can be seen below.
By analysing the power consumption at rest and during transmission, we can accurately predict how long these devices can operate with different power supplies. The real balancing act here is deciding on the length of time the device needs to be powered in the field and how often it needs to be transmitting data.
Why is this important?
As the number of transmissions increases, so to does the average power consumption. To maximise outcomes, our goal is to determine the minimum frequency of operation that generates the desired value. By reducing the frequency of transmissions where possible, we can dramatically increase the operational life expectancy of devices.
For example; a client might want to monitor the water and sewer levels of their networks and they have a series of devices that are logging data every second. However, they determine that a reading once a minute would surfice, so by writing a few lines of embedded code to alter the transmission frequency, we can extend the life of the devices by a factor of 60!
By determining from the outset where the lines cross between operational frequency and life of assets you will be operating from a position of maximium efficiency, saving time, money and effort.
Most common IoT power supplies
With all that said, let’s dive into the three most common methods of power supply for IoT devices and determine which option is right for you and your project.
1. Mains supply
In simple terms, mains power refers to the electrical supply from power stations to our homes and businesses which we access through our powerpoints. Every time you plug in your laptop, phone charger or microwave, you are leveraging mains electricity.
When to use mains power for your IoT devices?
Generally speaking, whenever we have access to mains power, we would utilise it as it offers the most reliable, consistent power supply to our devices.
Mains power is often required when we are using IoT systems and devices that have significant power consumption requirements that exceed the limits of battery power. The following applications would be considered high power:
- Camera/video imaging
- Real-time data capture with multiple parameters
- Digital displays
- Systems with multiple devices running at the same time (e.g. turbidity sensors, PH sensors, Air quality etc.)
Pros of mains
- Most reliable source of power
- The largest supply of power
- No additional investment in batteries required
Cons of mains
- Limited access points
- Usually unavailable in remote environments
- Often has significant regulatory barriers to tap into the supply for most commercial properties
Case study example
In 2020 our team at SAPHI developed a bespoke digital signage display controlled via a custom mobile app for a large CommBank facility in Sydney.
Because the system was required to power and control large LED panels 24 hours a day, the power requirements were far too high to run off battery. This meant the solution required access to a mains power supply to operate.
2. Vehicle battery
If your device is designed to be used in or around vehicles, tapping into the power supply of the vehicle is often a viable option.
When to use vehicle power for your IoT devices?
Whenever your device is mobile and is frequenctly in or around vehciles, tapping into the vehicle’s alternator will give you a steady supply of reliable power. The following applications could be considered good use cases for vehcile power:
- Extracting data from vehicles
- Vehicle monitoring (temperature, pressure, location)
- Digital displays
Pros of vehicle of battery
- Large and reliable source of power
- Enables use of mobile IoT devices
- No additional investment in batteries required
Cons of mains
- Can deplete battery of vehicle if devices are too power hungry
- Device will only run when vehicle is on
- Device size is limited depending on size of vehicle
Case study example
BHP was having difficulty managing and tracking the health of its assets. They needed a way to predict failures before they occurred in order to extend the life of their assets.
SAPHI designed and developed an industrial CAN bus vehicle sniffer system that enabled BHP to extract the data from its mining equipment and have it integrated into its predictive analytics system. The system had no access to mains power and was too power hungry to run on its battery alone so we designed the system to tap into the alternator of the vehicles to obtain the power it needed.
3. Solar + Battery
If mains supply is not an option, then a common alternative (provided the device is in direct contact with sunlight) is the use of a battery with attached solar system .
The battery supplies the necessary power and is topped up by the additional renewable energy from the solar panel to extend its operational life.
When to use battery + solar power for your IoT devices?
Battery and solar is a common power supply method for devices in remote areas that need to remain operational for longer periods of time than what a battery alone could support.
The following applications would be considered good applications for battery + solar:
- Remote monitoring applications e.g. environmental monitoring (waterways, pipelines etc.)
- Remote actuation of systems based on monitor readings e.g. dosing water based on PH levels
- Applications that require systems to be left in the field for long periods of time
Pros of battery + solar
- Enables the remote deployment of many IoT devices and systems for longer periods of time than battery alone
- Provides a consistent source of power to devices when mains power is not available
- Enables the use of smaller, more compact batteries as they are able to be recharged regularly
- Depending on the power consumption of IoT devices, how often they are switched on and the size of the battery, devices can last for weeks, months or even years before needing to be changed
Cons of battery + solar
- Requires investment in battery and solar panels which can be costly if the IoT system is large and complex
- Must have access to direct sunlight
- Cannot handle high-powered operations for long periods of time
Case study example
SAPHI have developed a series of battery + solar powered systems over the past six months to address the problems our clients were having around getting reliable readings on the quality and levels of their water. Our team recently developed three major systems for PH and turbidity detection as well as water level monitoring.
Each system has been deployed in remote, arid locations around Australia with direct access to sunlight and have been reliably logging the data they have been programmed to since their inception, providing on-going value to users.
4. Battery
If you have no mains supply and solar is not an option, then the 3rd best option is battery power for operating your IoT devices.
When to use battery power for your IoT devices?
Battery is a common option for power supply when we do not have access to mains power or solar supply. Battery is a great option for very low powered devices that are deployed in remote locations.
The following applications would be considered suitable applications for battery:
- Remote monitoring applications that do not require real-time data
- Applications that only require the device to operate for small periods of the day
Pros of battery
- Enables the remote deployment of some IoT devices and systems
- Provides a reliable source of power to devices
- Depending on the power consumption of IoT devices, how often they are switched on and the size of the battery, devices can last for weeks, months or even years before needing to be changed.
Cons of battery
- Depending on the power draw of your devices, you may require large battery systems which can prove costly.
- They limit the rate and amount of data you can collect
- They cannot handle high-powered operations for long periods
Case study example
Earlier this year, SAPHI developed a wearable COVID tracing system for a UK investor-backed startup. The system was designed using specialist technology to alert and trace in time, the user’s interactions with people who later tested positive for COVID-19.
Because the system was able to be regularly charged, we designed the solution to accommodate a small battery that would comfortably run through the day before needing to be topped up.
So which option is right for you?
Unless you have an engineering or electrical background, there might be a bit of a learning curve when it comes to selecting the right option that will ensure the longevity of your IoT systems, especially the edge cases where there is no clear answer. However, as a rough rule of thumb with a multitude of exceptions:
- If you have access to mains power and your devices can handle a 240v connection, go with that
- If your device is designed for vehciles, than tap into the alternator for a reliable power source.
- If you need to capture data in areas without access to mains supply but has direct sunlight, go for the battery with solar option
- Finally, if options one and two are not available, go for the solo battery
Thank you for reading!
Thank you for reading this article. We hope it gave you some valueable insights into power management and what option might be best for you.
Need support?
To find out more about what would work best for your individual circumstance, I encourage you to reach out to our team here at contact@saphi.com.au for a quick chat.
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