No matter how abundant, there has never been cheap and efficient long-term storage for energy produced from solar power, but new research has ushered in a possible solution.

Scientists in Sweden developed a specialized fluid, a solar thermal fuel, that can store energy from the sun for well over a decade.

The fluid is composed of carbon, hydrogen and nitrogen, and when it is hit by sunlight, the bonds between its atoms rearrange and it becomes energized. Researchers believe that the energy in this form can be stored for up to 18 years.

A prototype of the new technology is already being tested on the roof of the university. The renewable, emissions-free energy device is made up of a reflector with a pipe in the center, that tracks the Sun. The fluid is heated up by sunlight pumping through transparent tubes. The fluid can be stored at room temperature with little energy loss.

When the energy is needed, the fluid is passed through a catalyst that converts the molecules, warming the liquid by 63 degrees Celsius (113 degrees Fahrenheit). Researchers hope it can be used for heating systems, water heaters and much more before heading back to the roof for recharging.

The researchers have put the fluid through 125 cycles, picking up heat and dropping it off without significant damage to the molecule. The most recent study was published in Energy & Environmental Science.

Image: “Liquid gold” by Kevin Dooley is licensed under CC BY 2.0