Recent solar research is bringing down the cost of solar as well as increasing efficiencies. It is also expanding the use of solar in ways that can help solve environmental problems, like the need for clean drinking water. Here we present the latest cutting-edge research from around the world that is advancing solar technology as well as using it for the betterment of the world’s population.
Solar energy & water purification in one
Researchers at King Abdullah University of Science and Technology in Saudi Arabia developed a device that captures the heat shed by photovoltaic solar panels that can simultaneously generate electricity and water. Conventional PV panels have a maximum efficiency of 20%, and the remaining 80% is wasted, mostly in the form of heat. The researchers built a device in which a stack of water channels was attached to the underside of a commercial PV panel. Waste heat from the panel vaporized seawater; the vapor crossed the porous membrane and condensed as fresh water in a clean water channel below. As the vapor condensed, its heat passed through a layer to the next seawater channel, recycling the energy to purify more water. Read more about this work in Hybrid Solar Device Generates Electricity and Water at the Same Time.
Nanotubes create bulk photovoltaic effect
At the University of Tokyo, a physicist was exploring the possible functions of a special semiconductor nanotube, when he shone a laser on the nanotube to discover that certain wavelengths and intensities of light induced a current. What he had produced was the photovoltaic effect, demonstrating for the first time that nanomaterials could overcome an obstacle that will soon limit current solar technology. The current-inducing nanotube is made from rolled-up sheets of a special semiconductor material based on tungsten disulfide. The sheets must be rolled into tubes in order to induce a current in the presence of light. Read about this method and how it differs from traditional photovoltaic materials in Nanotubes Could Improve Solar Power and Imaging Technology
Thin film redistributes heat from the sun
A group of researchers at Chalmers University of Technology in Sweden demonstrated that a window film with a special module can help regulate indoor air temperature. The molecule captures the sun’s rays as photons and it changes form. In fact, when it has not absorbed any solar energy, the film is yellow or orange. When it changes form, it loses its color and becomes transparent. While it is absorbing solar energy, it is also keeping the sun’s heat from penetrating the film and heating the room. When the sun goes down, the heat starts to be released from the film. Read more about his Molecular Solar Thermal Storage in Solar Window Film Helps to Regulate Indoor Air Temperature
Creating solar cells with off-the-shelf components
Researchers at North Carolina State University created multi-junction solar cells using off-the-shelf components, resulting in lower cost, high-efficiency solar cells. Normally solar cells are constructed by stacking semiconductors with varying bandgaps on top of one another, allowing the cell to absorb different wavelengths of solar radiation. In an attempt to create high-efficiency solar cells at lower cost, the researchers used intermetallic bonding to bond solar cells made of different materials. They stacked an off-the-shelf gallium arsenide solar cell on top of silicon solar cell in a proof-of-concept demonstration. Read more about this simple and low-cost approach in Solar Cells Made with Off-the-Shelf Components.
Written by Anne Fischer, Managing Editor, Solar Novus Today