Beyond Electricity: Solar Fuels 

Solar fuels can be produced by using sunlight to split water or carbon dioxide molecules into their constituent elements, such as hydrogen and oxygen or carbon monoxide and hydrogen. This process can be done using various technologies, such as: 

• Photo-electrochemical cells: These devices use semiconductors to absorb sunlight and generate an electric current that drives the water or carbon dioxide-splitting reaction. 
• Photocatalytic cells: These devices use catalysts to accelerate the water or carbon dioxide splitting reaction under sunlight without requiring an external electric current. 
• Solar Thermal Systems: These use mirrors or lenses to concentrate sunlight onto a receiver that heats a fluid or gas that drives a chemical reactor. 

Solar fuels have several advantages over batteries, such as: 

• Higher energy density: Solar fuels can store more energy per unit mass or volume than batteries. 
• Longer duration: Solar fuels can be stored longer without losing quality or performance. 
• Lower cost: Solar fuels can be produced from abundant, cheap resources like water or air. 

Solar fuels require high temperatures and pressures to produce and store them efficiently. They also face competition from fossil fuels, which are still cheaper and more widely available. 

Australian researchers are developing novel materials and processes to improve the efficiency and cost-effectiveness of solar fuel production.  

For example, a project led by Professor Rose Amal from UNSW Sydney is developing nanostructured photocatalysts that can split water into hydrogen and oxygen using visible light.  

Another project Professor John Andrews from RMIT University led is developing a solar thermal system that can produce methane from carbon dioxide and hydrogen using a metal oxide redox cycle. 

Beyond Panels: Solar Skins 

Most solar panels are installed on rooftops or ground-mounted systems, which can be visually intrusive or take up valuable land space.  

A possible solution is to create solar skins, which are thin and flexible materials that can harvest solar energy and also serve as functional or decorative elements of buildings or vehicles. 

Solar skins can be made from various technologies, such as: 

• Organic Solar cells: These cells use organic molecules, such as polymers or dye-sensitised materials, to absorb sunlight and generate electricity. They can be made into colourful and transparent films that can be applied to various surfaces. 
• Quantum Dot Solar Cells: These cells use nanoscale crystals, called quantum dots, to absorb sunlight and generate electricity. They can be tuned to different colours and brightness levels by changing their size or shape. 
• Thermoelectric Materials: These materials can convert heat into electricity or vice versa. They can harvest waste heat from buildings or vehicles and turn it into useful power. 

Solar skins have several advantages over conventional solar panels, such as: 

• Versatility: Solar skins can be integrated into various shapes and forms, such as windows, walls, roofs, pavements, cars, buses or trains. 
• Aesthetics: Solar skins can be designed to match the colour and style of the existing environment or create new visual effects. 
• Functionality: Solar skins can also provide additional benefits, such as insulation, shading, lighting or communication. 

Solar skins are also still in the research and development stage and face challenges such as durability, reliability, and compatibility. Australian researchers are exploring new ways to create and apply solar skins for various applications.