No matter how rich or renewable, solar energy has a thorn in the side. There is still no cheap and efficient long-term storage for the energy it generates.
The solar industry has been involved in this industry for some time, but last year alone, a series of four papers provided a fascinating new solution.
Scientists in Sweden have developed a special fluid called solar thermal fuel that can store energy from the sun for over a decade.
"A solar thermal fuel is like a rechargeable battery, but instead of electricity, they emit sunlight and get heat that is triggered when needed." Jeffrey Grossman, an engineer who works with these materials at MIT, told NBC News ,
The liquid is actually a molecule in liquid form, the scientist at Chalmers University of Technology Sweden has been working on improvements for over a year.
This molecule is made up of carbon, hydrogen, and nitrogen, and when it is hit by sunlight, it looks unusual: the bonds between its atoms are rearranged and converted into an atom-saving new version of itself, called an isomer.
Like prey trapped in a trap, solar energy is trapped between the strong chemical bonds of the isomer and also stays there when the molecule cools to room temperature. [1
"The energy in this isomer can now be stored for up to 18 years," says a team from nanomaterials researcher Kasper Moth-Poulsen of Chalmers University. Emagazine.credit-suisse.com/app/art…2934 & lang = DE It increases the heat, which is greater than we dared to hope.
A prototype energy system located on the roof of a university building has put the new fluid to the test, researchers said. The results have attracted the attention of many investors.
The Renewable The zero emission power unit consists of a concave reflector with a tube in the middle, which tracks the sun like a kind of satellite dish.
The system works in a circle. The fluid is pumped through transparent tubing and heated by sunlight, turning the molecule norbornadiene into its heat-dissipating isomer quadricyclane. The liquid is then stored at room temperature with minimal energy loss.
When the energy is needed, the liquid is filtered through a special catalyst that returns the molecules to their original shape and heats the liquid by 63 degrees Celsius (113 degrees Fahrenheit).
The hope is that this heat can be used for home heating systems that power the water heater, dishwasher, tumble dryer, and more of a building before going back to the roof.
The researchers have passed the fluid This cycle has been performed more than 125 times, absorbing and removing heat without significantly damaging the molecule.
"We've made a lot of significant progress lately, and today we have an emission-free energy system that works all year round." says Moth-Poulsen.
After a series of rapid developments, the researchers claim that their liquid can now consume 250 watt-hours of energy per kilogram, which is twice the energy capacity of Tesla's Powerwall batteries, according to NBC. 19659002] But there is still much room for improvement. With the right manipulations, the researchers believe they could get even more heat from this system, at least 110 degrees Celsius more.
"There's still a lot of work to do, we just have the system to do it Now we have to make sure everything is designed the way it is," says Moth-Poulsen.
If everything goes as planned, Moth-Poulsen believes the technology could be commercially available within 10 years.
The latest study in the series has been published in Energy & Environmental Science .
A version of this article was first published in November 2018.