New material could help store solar power for years
In the search for innovative new ways to store power, researchers at Lancaster University have made an exciting new breakthrough.
Traditional solar photovoltaic cells capture the Sun’s light and transform the energy captured into an electrical current. One of the issues with this form of energy generation is as clear as day – literally. Sunlight only lasts so long, and intermittent bursts of light mean PV cells can only work so many hours during the day.
But Lancaster University researchers may have found a material that circumvents this issue. By looking at a mineral substance, they believe they may have identified a key component to help capture light, and convert it into heat energy, which can be stored for several months, before being finally expended.
The material in question is known in the scientific world as a ‘metal-organic framework’ (MOF), meaning it is a substance made of metal ions bound by carbon-based molecules, to create a solid 3D structure. By nature, MOFs are porous, allowing other materials to fill their gaps, allowing them to form a denser, composite material.
Researchers at Lancaster University filled the pores of a piece of MOF with azobenzene, which absorbs light, causing it to change shape. Likened to a coiled spring, the azobenzene molecules retain the energy in this ‘coiled’ state, before releasing it and reverting back to their natural state, when heat is applied as a trigger.
The material functions a bit like phase change materials, which are used to supply heat in hand warmers. However, while hand warmers need to be heated in order to recharge them, the nice thing about this material is that it captures “free” energy directly from the sun. It also has no moving or electronic parts and so there are no losses involved in the storage and release of the solar energy.– Dr John Griffin, Senior Lecturer, Materials Chemistry at Lancaster University
When snapping back into shape, the material itself gives off heat, which could be used to warm other devices. In the meantime, when stored at room temperature, this means the composite material could absorb large quantities of UV light and retain it for as long as four months. Scientists call this form of solar power retention ‘photoswitching’.
Unlocking the potential of UV light
The use of MOFs and other composite materials to absorb light, and ultimately store and disseminate energy is just the latest in a long line of innovations intended to make the most out of solar power. Photoswitching isn’t just limited to helping provide a more efficient way of generating and storing energy though.
It also has the potential to provide a new method of storing data, much in the same way a CD, DVD or Blu-ray uses various materials to store information on a small, reflective disk, but on a molecular level instead. The study even revealed that photoswitches could provide a revolutionary way of administering drugs to patients.
A simple application of heat or light could be the only trigger needed to help deliver medication into a patient’s bloodstream, as an example.
Compared to hydrocarbons such as coal, oil and gas, our Sun is a fully-functioning source of clean power, which has been burning for billions of years already. It’s estimated that it will continue to do so for many hundreds of millions of years to come, so that’s plenty of time to find a seamless way to harness its potential in full.