Lifeboat Foundation

Stacking solar cells increases their efficiency. Working with partners in the PERCISTAND project, researchers at the Karlsruhe Institute of Technology (KIT) have produced perovskite/CIS tandem solar cells with an efficiency of nearly 25%—the highest value achieved thus far with this technology. Moreover, this combination of materials is light and versatile, making it possible to envision the use of these tandem solar cells in vehicles, portable equipment, and devices that can be folded or rolled up. The researchers present their results in the journal ACS Energy Letters.

Perovskite solar cells have made astounding progress over the past decade. Their efficiency is now comparable to that of the long-established silicon solar cells. Perovskites are innovative materials with a special crystal structure. Researchers worldwide are working to get perovskite photovoltaic technology ready for practical applications. The more electricity they generate per unit of surface area, the more attractive solar cells are for consumers.

The efficiency of solar cells can be increased by stacking two or more cells. If each of the stacked solar cells is especially efficient at absorbing light from a different part of the solar spectrum, inherent losses can be reduced and efficiency boosted. The efficiency is a measure of how much of the incident light is converted into electricity. Thanks to their versatility, perovskite solar cells make outstanding components for such tandems. Tandem solar cells using perovskites and silicon have reached a record efficiency level of over 29%, considerably higher than that of individual cells made of perovskite (25.7%) or silicon (26.7%).

Whether or not a solid can emit light, for instance as a light-emitting diode (LED), depends on the energy levels of the electrons in its crystalline lattice. An international team of researchers led by University of Oldenburg physicists Dr. Hangyong Shan and Prof. Dr. Christian Schneider has succeeded in manipulating the energy-levels in an ultra-thin sample of the semiconductor tungsten diselenide in such a way that this material, which normally has a low luminescence yield, began to glow. The team has now published an article on its research in the science journal Nature Communications.

According to the researchers, their findings constitute a first step towards controlling the properties of matter through light fields. “The idea has been discussed for years, but had not yet been convincingly implemented,” said Schneider. The light effect could be used to optimize the optical properties of semiconductors and thus contribute to the development of innovative LEDs, solar cells, optical components and other applications. In particular the optical properties of organic semiconductors—plastics with semiconducting properties that are used in flexible displays and solar cells or as sensors in textiles—could be enhanced in this way.

Tungsten diselenide belongs to an unusual class of semiconductors consisting of a transition metal and one of the three elements sulfur, selenium or tellurium. For their experiments the researchers used a sample that consisted of a single crystalline layer of tungsten and selenium atoms with a sandwich-like structure. In physics, such materials, which are only a few atoms thick, are also known as two-dimensional (2D) materials. They often have unusual properties because the charge carriers they contain behave in a completely different manner to those in thicker solids and are sometimes referred to as “quantum materials.”

Some things that could make the world more efficient simply feel impossible to achieve — not like having to eat and sleep or not suffering through inflated grocery store prices.

Earlier this week, though, scientists at UC Riverside and the University of Delaware say they found a way to cross one of those seemingly impossible barriers when they convinced plants to grow in total darkness. A university press release says the team used a two-step process to convert carbon dioxide, electricity and water into acetate. Plants consumed the acetate and were able to grow in the dark.

The release said that combined with solar panels to generate electricity, this method of food production would be more than 18 times as effective as the natural process, which they claim uses only 1 percent of the energy found in sunlight alone. The team’s research was published Thursday in the journal Nature Food.

The researchers also optimized their electrolyzer to produce the highest levels of acetate ever produced in an electrolyzer to date. What’s more, they found that crop plants, including cowpea, tomato, rice, green pea, and tobacco, all have the potential to be grown in the dark using the carbon from acetate. There’s even a possibility that acetate could improve crop yields, though more research is required.

The researchers believe that by reducing the reliance on direct sunlight, artificial photosynthesis could provide an important alternative for food growth in the coming years, as the world adapts to the worst effects of climate change — including droughts, floods, and reduced land availability. “Using artificial photosynthesis approaches to produce food could be a paradigm shift for how we feed people. By increasing the efficiency of food production, less land is needed, lessening the impact agriculture has on the environment. And for agriculture in non-traditional environments, like outer space, the increased energy efficiency could help feed more crew members with less inputs,” Jinkerson explained.

A plan to export solar power from Australia to Singapore is advancing.

Development backed by billionaires aims to export clean power from the Northern Territory via a 2,600-mile high-voltage undersea cable.

Now, researchers at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have demonstrated a tin-lead perovskite cell that overcomes problems with stability and improves efficiency.

To improve cell stability, NREL researchers used a hole-transporting material made of phenethylammonium iodide and guanidinium thiocyanate. Researchers noted that the formation of quasi-two-dimensional (quasi-2D) structures from additives based on mixed bulky organic cations phenethylammonium and guanidinium provides critical defect control to substantially improve the structural and optoelectronic properties of lead-perovskite thin films with a narrow-bandgap of 1.25 eV.

The new tandem solar cell design with two layers of perovskites measured a 25.5% efficiency. It retained 80% of its maximum efficiency after 1,500 hours of continuous operation or more than 62 days.

Jackson, Michigan-based Sesame Solar is today unveiling what it claims is the world’s first fully renewable mobile nanogrid – that’s a small microgrid – that runs on solar and green hydrogen.

The nanogrid’s solar array is electronically unfolded, and it’s ready to start generating power within 15 minutes. The company claims it can be set up by a single person.

Continue reading “Check out this solar + green hydrogen mobile nanogrid with a level 2 EV charger” »

Everything is about to be illuminated.

A team of researchers from Imperial College London and Newcastle University has just observed what happens after light strikes solar cells.

Continue reading “What happens when light hits solar cells? Scientists just observed the first moments” »

Ricoh, European startups race to bring flexible power source to market this year.

TOKYO — A thin, flexible alternative to silicon-based solar cells is set to be produced in greater volumes, opening up more uses for renewable energy such as powering indoor smart devices.

Organic solar cells are made by printing photovoltaic material on plastic sheets and other bendable substrates. They are expected to cost half as much to make as silicon-based solar cells and are 100 times lighter, manufacturers say.

Continue reading “Solar power anywhere: Lightweight organic cells aim beyond rooftops” »