No matter how abundant or renewable, the solar energy has a thorn in its own country. There is still no cheap and effective long-term storage of the energy it generates.
The solar industry is stuck for this branch for a while, but only in the last year, a series of four articles has found an intriguing new solution.
Scientists in Sweden have developed a specialized fluid called solar thermal fuel that can store energy from the sun for more than a decade.
"Solar thermal fuel is like a rechargeable battery, but instead of electricity, you put sunshine and heat up, triggered on demand," Jeffrey Grossman, an engineer working with these materials at MIT, told NBC News.
The fluid is actually a molecule in liquid form that scientists at Chalmers University of Technology, Sweden, have been working on for over a year
This molecule is made up of carbon, hydrogen and nitrogen, and when it is hit by sunlight, it makes something unusual: the relationships between its atoms are rearranged, and it becomes an energized new version of itself called the isomer
Like trap caught, so the energy of the sun is trapped between the strong chemical bonds of the isomer and stays there, even when the molecule is cooled to room and temperature. 659002] When energy is needed ̵
"Energy in this isomer can be stored for up to 18 years," says one of the scientists from nanomaterials Kasper Mott-Polsen of Chalmers University.
"And when we come to extract energy and use we get an increase in heat that is greater than we hoped for."
A prototype of the energy system placed on the roof of a university building put the new test liquid and according to researchers
The energy-free device consists of a concave reflector with a pipe in the center that tracks the sun as a kind of satellite dish
The system The liquid is heated by the sunlight, converting the norbornadiene molecule into its heat-capturing isomer, quadricyclamine, and then storing the liquid at room temperature with minimal energy loss
When energy is needed , the liquid is filtered through a special catalyst that turns the molecules back into their original form, warming the liquid 63 degrees Celsius (113 degrees). Fahrenheit).
The hope is that this heat can be used for domestic heating systems, power to the building's water heater, dishwasher, clothes dryer and much more before returning to the roof again. this cycle is more than 125 times, capturing the heat and releasing it without significant damage to the molecule.
"We have achieved a number of important achievements recently, and today we have an emissions-free energy system that works all year round." After a series of rapid developments, researchers said their liquid could hold 250 watts of energy per kilogram, twice as much as the energy capacity of Tesla Powerwall batteries, according to NBC.
But there is still room for improvement. With the right manipulations, researchers believe they can get even more heat from this system, at least 110 degrees Celsius (230 degrees Fahrenheit).
"There is still a lot to be done, and now we have to make sure that everything is optimally designed," says Moth-Poulsen.
If everything goes as planned, Moth-Poulsen believes that technology can be commercially available within 10 years.
The latest research in the series is published in Energy and Ecology .
This article was first published in November 2018.