Internet of Things and Power

How do you power devices at the top of mountains and the bottom of oceans? Let's find out!

Weather-related devices, car computers, smart refrigerators and appliances, personal health monitors, and shipping container monitors are examples of the internet of things (IoT). They have computers that collect data which is processed on the device or sent elsewhere to be evaluated.

In the world of the internet of things, engineers are really excited to put their devices all around the world. They want to put gadgets in fields, underwater, up mountains, and all around our cities and towns. There’s one problem, though; how do you power them all?

You can’t really plug them into the mains; after all, there are no plug sockets in the sea! Batteries are a good idea, but there’s the problem of having to go out and change them every so often. It’s better to have it so they can power themselves instead of needing us to power them.

While this does open the door for stuff like solar power, engineers can go one step further. IoT devices are designed to use as little energy as possible so they can properly “survive” in the wild. This allows engineers to draw energy from places you wouldn’t expect!

Let’s take a look at IoT devices in the open sea. How do you think a device could generate energy while in the water? If it’s floating, solar power might work — but what if it’s underwater?

Some really smart scientists have found something to power an underwater device with; sound. Sound waves contain energy — that’s how it can reach our ears in the first place. Researchers have found a way to transmit a sound wave through the water which a submerged IoT device can use for energy.

When one of these underwater devices receives energy from a sound wave, it has one of two choices. It can either use the energy to send a message back or — if it doesn’t need to phone home — it can choose to “eat” the energy to keep its rechargeable battery topped up.

How about drawing energy from something that’s alive? You may have heard of a potato clock, which uses the really small amount of electricity in a potato to display the time. Scientists have pushed this one step further to harvest energy from grass. Yes, the very same stuff that grows in gardens!

These little sensors can be placed in fields and used to monitor the soil quality. This is great for farmers and gardeners because they can track how their plants are doing without leaving their armchair.

To do this, the sensor drinks up the electricity generated by plants. Before you think about plugging your phone into your lawn, it’s worth mentioning that this method only generates a 2 milliwatt charge — that’s 0.002 watts! Very tiny!

Still, the sensor can use this to do its job. Every three hours it uses 75 milliwatts to send a message home, and 150 milliwatts to send a message to a satellite. It takes a little while for it to charge up to these levels, but it’s still impressive for a device running off of grass!

Learn More

Water IoT

Plant IoT

Controlling algae with sound waves

Technology converts sound waves to electricity

Generating electricity from living plants

Electric bacteria create currents

Five unusual energy sources

Unusual sources of energy

Alternative energy

How to extract energy from grass


  • Simon Batt

    Simon Batt is a UK-based tech enthusiast and all-around geek. His favourite things are cups of tea, cats, and new gadgets, even though they never mix well.

Also In The April 2020 Issue

As students reach the age of 13 the importance of them understanding their rights and privacy online becomes crucial.

The iDTech summer camp recently posted 102 questions. Here are a few with links to the full list.

Being well-read is essential in everything in life, and coding is no exception! Here are some book recommendations to make you a coding master.

The circus is in town, but they're missing one of their colourful balls. Let's make one for them!

Sundials were one of the first ways people kept track of time. But how did they work?

New to physical computing? MircoPython may be perfect or you!

It's project time! In this article we go over how the same processes used in big factories can be used to control a simple LED.

What do bubbles, pancakes, and spaghetti all have in common? They're all great for sorting!

Yee-ha! In the wild wild west of the internet, antivirus software is a must-have partner.

Exploring the concept of RAM and how it helps your MInecraft game run better.

Breaking down big problems into smaller ones is a great way to solve them. Let's see how recursion helps us do this!

How did this pale blue dot that we call Earth first begin? The answer is even more fascinating than imagined.

Have you ever wondered why your computer's mouse is called that? Well it all started with a fellow named Douglas and a block of wood...

How do you power devices at the top of mountains and the bottom of oceans? Let's find out!

Links from the bottom of all the April 2020 articles, collected in one place for you to print, share, or bookmark.

Interesting stories about computer science, software programming, and technology for April 2020.

Interested but not ready to subscribe? Sign-up for our free monthly email newsletter with curated site content and a new issue email announcement that we send every two months.

No, thanks!