Solar panels may be worse for than environment than we thought, but researchers say there’s still time to change that with a new panel design.
https://youtube.com/watch?v=4TCg4vsz6Ac
Reeman Dyson, one of the 20th century’s greatest theoretical physicists, died this week aged 96. He is known for popularising the Dyson Sphere – a hypothetical megastructure that could surround an entire star, capturing all of its solar energy.
At 35 meters, the wingspan of the new BAE Systems aircraft equals that of a Boeing 737, yet the plane weighs in at just 150 kilograms, including a 15 kg payload. The unmanned plane, dubbed the PHASA-35 (Persistent High-Altitude Solar Aircraft), made its maiden voyage on 10 February at the Royal Australian Air Force Woomera Test Range in South Australia.
“It flew for just under an hour—enough time to successfully test its aerodynamics, autopilot system, and maneuverability,” says Phil Varty, business development leader of emerging products at BAE Systems. “We’d previously tested other sub-systems such as the flight control system in smaller models of the plane in the U.K. and Australia, so we’d taken much of the risk out of the craft before the test flight.”
The prototype aircraft uses gallium arsenide–based triple-junction solar cell panels manufactured by MicroLink Devices in Niles, Ill. MicroLink claims an energy conversion efficiency of 31 percent for these specialist panels.
Researchers at Northern Illinois University and the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) in Golden, Colorado, are reporting today (Feb. 19) in the journal Nature on a potential breakthrough in the development of hybrid perovskite solar cells.
Considered rising stars in the field of solar energy, perovskite solar cells convert light into electricity. They’re potentially cheaper and simpler to produce than traditional silicon-based solar cells and, on a small scale in laboratory settings at least, have demonstrated comparable efficiency levels. But key challenges remain before they can become a competitive commercial technology.
One major challenge is the use of lead. Most top-performing hybrid perovskite solar cells contain water-dissolvable lead, raising concerns over potential leakage from damaged cells.
Researchers have developed quantum dot solar cells that can be made into thin, flexible films and used to generate electricity even in low-light conditions.
Steven Hawking: “I don’t think we will survive another thousand years without escaping beyond our fragile planet.”
Probably the most notable direct result of space exploration is satellites. Once we could position a ship in orbit and take telemetry, we knew we could place unmanned pieces of equipment there and just let it orbit, running on its own, while receiving orders from the ground. From those satellites, we have created a global communication system and the global positioning system (GPS) that powers most of our communications capabilities today. What can bring peace and harmony on the planet more than our ability to communicate with each other beyond geographic and political boundaries? These technologies have been enhancing and saving for years.
Next week, the European Space Agency is going to jettison a cubesat called Qarman from the International Space Station and watch it burst into a fireball as it reenters Earth’s atmosphere—all on purpose.
What’s the mission: Qarman (short for “QubeSat for Aerothermodynamic Research and Measurements on Ablation”) is a shoebox-sized experiment meant to help researchers better understand the physics at play when objects plummet into the planet’s atmosphere and burn up. Qarman was brought up to the ISS in December during a cargo resupply mission. On February 17, it will be cast back out into space and begin slowly drifting toward Earth before entering the atmosphere and burning up in about six months.
Tell me more: Qarman has four solar-cell-covered panels that are designed to increase atmospheric drag and hasten reentry. Its nose is made from a special kind of cork that’s typically used in thermal protection systems on spacecraft. Ground testing shows that when the cork heats up, it chars and flakes away a bit at a time. The Qarman team is interested in learning how this process works during reentry.
The University of Rochester research lab that recently used lasers to create unsinkable metallic structures has now demonstrated how the same technology could be used to create highly efficient solar power generators.
In a paper in Light: Science & Applications, the lab of Chunlei Guo, professor of optics also affiliated with Physics and the Material Sciences Program, describes using powerful femto-second laser pulses to etch metal surfaces with nanoscale structures that selectively absorb light only at the solar wavelengths, but not elsewhere.
Continue reading “Lasers etch a ‘perfect’ solar energy absorber” »
What if solar cells worked at night? That’s no joke, according to Jeremy Munday, professor in the Department of Electrical and Computer Engineering at UC Davis. In fact, a specially designed photovoltaic cell could generate up to 50 watts of power per square meter under ideal conditions at night, about a quarter of what a conventional solar panel can generate in daytime, according to a concept paper by Munday and graduate student Tristan Deppe. The article was published in, and featured on the cover of, the January 2020 issue of ACS Photonics.
Munday, who recently joined UC Davis from the University of Maryland, is developing prototypes of these nighttime solar cells that can generate small amounts of power. The researchers hope to improve the power output and efficiency of the devices.
Munday said that the process is similar to the way a normal solar cell works, but in reverse. An object that is hot compared to its surroundings will radiate heat as infrared light. A conventional solar cell is cool compared to the sun, so it absorbs light.
In order to develop solar panels that generate electricity at night, you just need them to operate in the exact opposite way solar panels work during the day.
