The Brand New Technology Harvesting Energy from Thin Air

The temperature change from day to night can be used to generate energy

Our energy needs are diverse, and so are the new innovations to harness different energy sources to supply our demands.

Autor*in Tristan Rayner, 03.29.18

Our energy needs are diverse, and so are the new innovations to harness different energy sources to supply our demands.

We’ve been looking at a whole host of interesting and innovative solutions for energy generation recently: from NASA’s floor tiles that capture energy from your footsteps, and “solar” panels that generate energy from rainfall, all the way to sensors powered by our own bodily fluids.

Last week, we looked at the possibilities offered by tech which lets us harvest water from the air, via a range of proven techniques to capture evaporated moisture and create clean drinking water. And now it looks like we might even be able to harvest energy from the air as well.

How does that work?

Engineers from the Massachusetts Institute of Technology (MIT) have pursued this idea using a small device called a thermal resonator to capture energy from changing air temperatures (which occur naturally throughout a day-night cycle in many climates across the world) or even from waste heat sources.

Using new concepts from materials science, the researchers published a paper in the journal Nature, highlighting how special materials can dynamically exploit temperature fluctuations, needing as little as a 10 degree Celsius fluctuation to generate small amounts of persistent power, which could be useful as long-term power sources for low-drain, remote devices and sensors.

This thermoelectric system works by capturing heat on one side of the device material only and slowly radiating it across to the other side. By maintaining a common difference, the self-contained, and fully-portable device can consistently generate power.

It is a different approach to other explorations into converting thermal energy into electrical energy – including solar thermal panels, which are now commercially common. This device uses “high-thermal effusivity materials” to allow it to operate in the shade and in any kind of wind condition. It also outperforms other materials, such as more common pyroelectric materials, by a factor of more than three, in terms of power per area.

“We’ve built the first thermal resonator,” says Anton Cottrill, the study’s lead author.

“It’s something that can sit on a desk and generate energy out of what seems like nothing. We are surrounded by temperature fluctuations of all different frequencies all of the time. These are an untapped source of energy.”

While researchers explained that the ideal application of the current device would be difficult to access locations, where batteries need regular replacement or recharging, this kind of technology could also have a significant impact when combined with waste heat, such as in industrial applications or the warmth given off by servers in data centres.

It could also be used as a complement to photovoltaic solar panels, which get less efficient the hotter they become. Adding a device with this kind of heat-to-energy technology could reduce heat stress on the PV cells and cool them down, while at the same time generating bonus electricity by taking the heat away and converting it. Win-win!

Solar Power For a Rainy Day: Experimental Panels Generate Electricity From Rain Water

A new experimental solar panel is under development which hopes to generate electricity come rain or shine.

Airborne Power Stations Take Wind Energy to New Heights

Flying wind parks could dramatically increase the efficiency of renewable energy production.

Gravitricity: The Scottish Startup Turning Mine Shafts Into Green Energy Stores

Former mines around the world could soon be enjoying a second lease life thanks to cutting edge technology developed by an Edinburgh startup.

Pavegen: Generate Clean Electricity While Taking a Stroll

The flooring of the future: introducing a high tech pavement tile that generates electricity and data from every step.

A New Material Could Help to Solve the Issue of How to Store Solar Thermal Energy

Researchers at MIT have developed a material that can store heat and release it when needed - meaning exciting possibilities for the future of solar thermal power.

These Parisians Are Splashing Into Water Heated by Servers

Fancy swimming in an eco-friendly pool, heated using the waste energy used to produce your favourite animated movie?

Cloud&Heat Transforms Servers Into Water Heaters

As the world becomes increasingly digitalised, the need for servers - to store and process the huge amounts of data that we're producing - grows with it. A startup from Dresden, Cloud&Heat, has come up with a way of transforming all the warmth they give off into more than just a bunch of hot air.

Solmove: Will German Cars Soon Be Driving on Solar Roads?

The German startup Solmove has developed a system of glass panels embedded with solar cells that can be used to cover roads and generate energy. It's the latest step in solar road technology, and looks set to give a boost to the electric car market too.