Scientists build high-performing hybrid solar energy converter

Science Daily  July 15, 2020 A team of researchers in the US (UC San Diego, Tulane University, San Diego State University) has developed a hybrid solar energy converter that generates electricity and steam with high efficiency and low cost. It utilizes an approach that more fully captures the whole spectrum of sunlight. It generates electricity from high efficiency multi-junction solar cells that also redirect infrared rays of sunlight to a thermal receiver, which converts those rays to thermal energy. Energy can be stored until needed. In demonstrations it operated at 85.1 percent efficiency, delivered steam at up to 248°C, and […]

Lasers etch a ‘perfect’ solar energy absorber

Nanowerk  February 4, 2020 Direct femtosecond laser processing fabrication technique can effectively modify the optical, electrical, mechanical, and tribological properties of materials for a wide range of potential applications. However, it is difficult to precisely control the surface properties. Researchers at the University of Rochester have developed a process to obtain more control over spectral light absorption. They experimentally demonstrated spectral control of a variety of metals (copper aluminium, steel and tungsten), resulting in the creation of broadband light absorbers and selective solar absorbers (SSAs). They have shown that fs-laser-produced surfaces can be used as high-temperature SSAs and demonstrated that […]

Researchers find a way to harness the entire spectrum of sunlight  January 21, 2020 Researchers at the Ohio State University have shown that it is possible to collect energy from the entire visible spectrum of sunlight, including low-energy infrared, and transform it quickly and efficiently, into hydrogen. What makes it work is that the system is able to put the molecule into an excited state, where it absorbs the photon and is able to store two electrons to make hydrogen. They figured out a way make a catalyst out of one molecule of the element rhodium which means less energy is lost. The system is nearly 25 times more efficient […]

An artificial sunflower that bends toward the sun  November 5, 2019 A team of researchers in the US (UCLA, Arizona State University, industry) has created, sunflower-like biomimetic omnidirectional tracker (SunBOT), an artificial phototropic system based on nanostructured stimuli-responsive polymers that can aim and align to the incident light direction in the three-dimensions over a broad temperature range. Such adaptive reconfiguration is realized through a built-in feedback loop rooted in the photothermal and mechanical properties of the material. They have shown that an array of SunBOTs can, in principle, be used in solar vapour generation devices, as it achieves up to a 400% solar energy-harvesting enhancement over non-tropistic […]

Nanotechnology breakthrough enables conversion of infrared light to energy  October 31, 2019 Invisible infrared light accounts for half of all solar radiation on the Earth’s surface, yet ordinary solar energy systems have limited ability in converting it to power. A team of international researchers (Sweden, China) has developed film combining nanocrystals with chains of microlenses that can be applied on top of ordinary solar cells. The ability of the microlenses to concentrate light allows the nanoparticles to convert the weak IR light radiation to visible light which is useful for solar cells increasing their efficiency by 10 percent or more…read more. Open Access TECHNICAL ARTICLE 

Welcome indoors, solar cells

Eurekalert  September 16, 2019 An international team of researchers (China, Sweden) developed a new combination of donor and acceptor materials, with a carefully determined composition, to be used as the active layer in an organic solar cell. The power they produce is low but is probably enough to feed the millions of products IoT products. They designed a non-fullerene acceptor named IO-4Cl and blend it with a polymer donor named PBDB-TF to obtain a photoactive layer whose absorption spectrum matches that of indoor light sources. The photovoltaic characterizations reveal a low energy loss below 0.60 eV. As a result, the organic […]

In the future, this electricity-free tech could help cool buildings in metropolitan areas

EurekAlert  August 5, 2019 An international team of researchers (University of Buffalo, University of Wisconsin, Saudi Arabia, China) fabricated an inexpensive planar polydimethylsiloxane (PDMS)/metal thermal emitter thin film structure using a fast solution coating process that is scalable for large-area manufacturing. The spectral-selective structure was designed and implemented to suppress the solar input and control the divergence of the thermal emission beam enhancing the directionality of the thermal emissions, so the emitter’s cooling performance was less dependent on the surrounding environment. In tests under different environmental conditions, temperature reductions of 9.5 °C and 11.0 °C in the laboratory and outside environment, respectively, […]

Novel thermoelectric nanoantenna design for use in solar energy harvesting

Nanowerk  May 3, 2019 Researchers in Mexico fabricated and compared bimetallic Ni-Pt nanoantennas for a classic and evolutive dipole configuration. Observing the thermoelectric voltage dependence associated with classic and evolutive dipole configuration they found that the evolutive dipole nanoantennas (EDN) generate up to three times more voltage in contrast with the classic dipole nanoantenna (CDN). The evolutive configuration is 1.3 times more efficient than its classical counterpart. The results are corroborated by absorbance of these nanoantennas in the 20 to 36 THz range, where EDN is 40% more efficient than CDN and 30% in the range of 36.1 to 90 […]

“Sun in a box” would store renewable energy for the grid

MIT News  December 5, 2018 A team of researchers in the US (MIT, Georgia Institute of Technology, National Renewable Energy Laboratory) has outlined their concept for a new renewable energy storage system, which they call Thermal Energy Grid Storage-Multi-Junction Photovoltaics (TEGS-MPV). The new design stores heat generated by excess electricity from solar or wind power in large tanks of white-hot molten silicon, which can withstand high temperatures of over 4,000 degrees Fahrenheit and then converts the light from the glowing metal back into electricity when it’s needed. Previously they developed a pump that could withstand such blistering heat and could conceivably […]

Nanoparticles Take Solar Desalination to New Heights

IEEE Spectrum  August 10, 2018 Researchers in China have demonstrated that by dispersing tellurium nanoparticles into water, the water evaporation rate is improved by a factor of three under solar radiation. This makes it possible to increase the water temperature from 29 degrees to 85 degrees Celsius within 100 seconds. The Te nanoparticles perform like a plasmonic nanoparticle when it is smaller than 120 nanometers and then as a high-index all-dielectric nanoparticle when those nanoparticles are larger than 120 nm as they have a wide size distribution (from 10 to 300 nm). This enhanced absorption can cover the whole solar […]