Researchers from North Carolina State University and the Chinese Academy of Sciences have created an efficient, semi-printed plastic solar cell without the use of environmentally hazardous halogen solvents. These solar cells can be manufactured at room temperature, which has implications for large-scale commercial production.
Plastic solar cells, or organic photovoltaics, are popular because they are lightweight, flexible, transparent and inexpensive to manufacture, making them useful in multiple applications. Unfortunately, the halogen-containing solvents used in their manufacture are an obstacle to large-scale commercialization. These solvents are key to making sure that the solar cell’s morphology, or structure, maximizes its energy efficiency; however, they are environmentally hazardous. Additionally, the use of these harsh chemicals requires a controlled environment, which adds to production costs.
Long Ye, a postdoctoral research scholar in physics at NC State and lead author of a paper describing the work, wanted to find out if nontoxic solvents could provide equally efficient morphology in the manufacturing process. Ye and his colleagues developed a proof of concept semi-printed plastic solar cell that utilized o-methylanisole (o-MA) as the solvent. O-MA is a commonly used flavoring agent in foods, and is nontoxic to humans.
The researchers used soft X-ray techniques to study the morphology of their solar cell. They found that the o-MA based solar cell had similar morphology, crystalline features and device performance to those produced by halogenated solvents. The solar cell’s overall efficiency rating was around 8.4 percent. Furthermore, their cell could be produced via blade coating at ambient, or room temperature. Blade coating is a process that uses a glass blade to spread a thin layer of the photovoltaic film onto either a rigid or flexible substrate, and the process is compatible with large-scale commercial manufacturing.
“Two of the key requirements for mass producing these solar cells are that the cells can be produced in the open air environment and that the process doesn’t pose health or environmental hazards,” Ye says. “Hopefully this work can help pave the way for printing solar cells in ambient air.”
Learn more: Food Additive Key to Environmentally Friendly, Efficient, Plastic Solar Cells
The sun is a clean and inexhaustible source of energy, with the potential to provide a sustainable answer to all future energy supply demands. There’s just one outstanding problem: the sun doesn’t always shine and its energy is hard to store. For the first time, researchers at the Paul Scherrer Institute PSI and the ETH Zurich have unveiled a chemical process that uses the sun’s thermal energy to convert carbon dioxide and water directly into high-energy fuels: a procedure developed on the basis of a new material combination of cerium oxide and rhodium. This discovery marks a significant step towards the chemical storage of solar energy.
The researchers published their findings in the research journal Energy and Environmental Science.
The sun’s energy is already being harnessed in various ways: whilst photovoltaic cells convert sun light into electricity, solar thermal installations use the vast thermal energy of the sun for purposes such as heating fluids to a high temperature. Solar thermal power plants involve the large-scale implementation of this second method: using thousands of mirrors, the sun light is focused on a boiler in which steam is produced either directly or via a heat exchanger at temperatures exceeding 500 °C. Turbines then convert thermal energy into electricity.
Researchers at the Paul Scherrer Institute PSI and the ETH Zurich have collaborated to develop a ground-breaking alternative to this approach. The new procedure uses the sun’s thermal energy to convert carbon dioxide and water directly into synthetic fuel.
The “Internet of Things” could make cities “smarter” by connecting an extensive network of tiny communications devices to make life more efficient. But all these machines will require a lot of energy. Rather than adding to the global reliance on fossil fuels to power the network, researchers say they have a new solution.
An Aston University academic has proposed a new process to decompose waste desalination brine using solar energy, neutralising ocean acidity and reducing damaging environmental impacts.
Although turning salty ocean water into fresh water is important to benefit poverty-stricken populations, desalination has a very damaging ecological footprint. Many environmental advocates see it as a last resort for retrieving fresh water, but fast growing populations mean it is becoming the only viable option. The amount of fresh water produced by desalination is predicted to double within the next decade to meet global demand.
Dr Philip Davies, of Aston’s School of Engineering and Applied Science, has devised a system using solar energy that could allow desalination plants to act as a sink, rather than a source of atmospheric carbon dioxide, and help to neutralise ocean acidity.
In Dr Davies’s model, magnesium chloride in waste brine is hydrolysed by energy generated by heliostat fields to magnesium oxide, which is discharged to the ocean. Due to its alkaline nature, this subsequently neutralises ocean acidity and gradually removes carbon dioxide through the conversion of magnesium oxide to bicarbonate, similar to ocean liming.
Although this approach increases the energy requirement of the plant by 50%, Dr Davies has calculated that this is offset by the carbon dioxide absorption capacity. His process would result in 0.4% of anthropogenic carbon dioxide emissions being absorbed given a doubling in the current desalination capacity.