Lead research Isabell Thomann. Pic credit: Rice University
Lead research Isabell Thomann. Pic credit: Rice University

In the US, Researchers from Texas-based Rice University have demonstrated a new efficient method of harnessing power from the sun and converting it into clean power by splitting water molecules.

According to a statement released by the University, the technology relies on a configuration of light-activated gold nanoparticles, which harvest sunlight and transfer solar energy to highly stimulated electrons, which scientists refer to as “hot electrons”.

Hot electrons: Saving wasted energy

Lead researcher Isabell Thomann, assistant professor at Rice University explained: “Hot electrons have the potential to drive very useful chemical reactions, but they decay very rapidly and people have struggled to harness their energy.”

Energy losses of today’s solar photovoltaic technology could be attributed to the hot electrons cooling within a few trillionths of a second, which then release their energy as wasted heat.

If the hot electrons are captured before they reach the cool down stage, solar-energy providers could increase their solar-to-electric power-conversion efficiencies and subsequently reduce the cost of solar power.

Science involved

According to the University statement: “In the light-activated nanoparticles, light is captured and converted into plasmons, which are waves of electrons that flow like a fluid across the metal surface of the nanoparticles.

“Plasmons are high-energy states that are short-lived but researchers have found ways to capture plasmonic energy and convert it into useful heat or light.”

Thomann said: “Utilising hot electron solar water-splitting technologies were on par with considerably more complicated structures that also use more expensive components.”

She added: “We are confident that we can optimise our system to significantly improve upon the results we have already seen.”

New clean power technology

In the UK, a Cape Town native design engineering student has designed a new energy generation system to enable households that cannot accommodate solar panels to generate their own clean power.

Innovator Charlotte Slingsby said that the prototype can generate an estimated 10% of the energy per square metre that a solar panel can.

Motivated by her parents’ home that is not suitable for solar panels, Slingsby designed the product to be mounted to surfaces and areas that are not typically used for energy generation, such as under bridges.

Slingsby said: “It is reduced in efficiency but it is looking at a new type of material, which has the ability to go in far more locations. It is all about accessibility to captured energy.”