Tag: solar power

Scientists generate organic solar cells that reliably work for 27,000 years outdoors

On By A.P.In UncategorizedLeave a comment

Thin, transparent and flexible, organic solar cells look perfect for harnessing the sun’s energy from pretty much any surface, including windows, vehicles and smartphones. But they’ve been dogged by the perception that they’re not stable enough to survive in the real world. Now researchers in the US have demonstrated it’s possible to create organic solar cells that reliably work for 27,000 years outdoors, quashing the idea that long-lived devices are impossible.

The reliability of organic photovoltaic (OPV) cells has been one of the biggest hurdles to practical applications. Even the most stable ones typically don’t last longer than seven years, degrading due to the effects of light and heat. It led many to believe that solar cells made from weakly bonded organic materials simply couldn’t be made to rival the longevity of traditional silicon devices.

But Stephen Forrest’s group at the University of Michigan has put this idea to rest by showing that C70 fullerene-based single junction OPVs can survive the glare of the sun for far longer than any commercial device would require – around 27,000 years. The team extrapolated this number by artificially ageing the cells using heat and intense light.

‘We have shown that organic solar cells aren’t particularly difficult to stabilise – it depends on choice of materials, fabrication processes and device architectures,’ says Forrest. ‘It is now clear that the intrinsic lifetime of OPVs can be sufficient to achieve the practical lifetimes met by conventional, inorganic cells.’

The researchers made thin-film organic solar cells in a series of layers, like a nano-scale multi-layered sandwich, using vapour deposition to precisely control the thickness and purity of each layer. The experimental devices had efficiencies of 6–7% – by comparison commercial silicon solar cells have efficiencies of around 20%. Initial experiments, which simulated the light and heat intensity of the sun using a xenon arc lamp revealed that the cells degraded too slowly to be measured over the course of a year. So the team rigged up a system of white LEDs which could artificially age a fresh set of OPV cells by subjecting them to light intensities that delivered the equivalent of up to 37 suns.

After exposure for more than 68 days, the cells maintained more than 87% of their starting efficiency. The team were able to extrapolate from the results that it would take the equivalent of 27,000 years outdoors for the cells to lose 20% of their original efficiency – the point at which the team deemed the device no longer useful. What’s more, no efficiency loss was observed in cells subjected to nine years’ worth of UV radiation.

‘The extrapolated lifetimes were exceptionally long, particularly compared to all previous reports of device lifetimes. Yet, “short lifetime” as a feature of all organic devices is a myth, as has been proven for [organic LEDs],’ explains Forrest. ‘So while the very long intrinsic lifetime is surprising, it is within reasonably expected values for the best organic devices reported in other application spaces.’

‘The excitement of this paper is that it debunks the common belief that organic materials are unstable and that long-lived organic solar cells are simply not possible,’ says Paul Dastoor, who develops organic solar cells, including a solar paint, at the University of Newcastle, Australia. ‘Indeed, our own work is showing that it is the packaging and encapsulation that is far more critical to obtaining long device lifetimes rather than organic material stability.’

References
Q Burlingame et al, Nature, 2019, DOI: 10.1038/s41586-019-1544-1

https://www.chemistryworld.com/news/can-organic-solar-cells-stand-the-test-of-time/3010957.article?adredir=1#/

Tesla solar roofing

On By A.P.In Solar Energy, solar powerLeave a comment

by Matt Hickman

When Tesla, the Silicon Valley automaker and energy storage firm founded by billionaire and Mars colonization enthusiast Elon Musk, unveiled its gorgeous solar roofing system back in October, it was assumed that said shingles would be significantly spendier than conventional roofing — you know, roofing that isn’t capable of transforming free and abundant sunshine into a form of home-powering renewable energy.

After all, why would a roof that’s more durable, longer-lasting and flat-out sexier also be comparable in price — or, gasp, even more affordable — than a traditional asphalt roof?

Weeks later, Musk, a clean tech entrepreneur never without a few surprises up his sleeve, is claiming that Tesla’s sleek solar roofing option will indeed be the cheaper option even before the annual energy savings associated with having an electricity-producing roof kick in.

Made from tempered glass, Tesla’s low-cost solar roofing shingles are slated for a widespread rollout at the end of 2017.

Musk made the potentially too-good-to-be-true claim directly following last week’s announcement that Tesla shareholders had voted to merge with SolarCity, the residential solar behemoth founded by Musk’s cousin Lyndon Rive. (Musk himself serves as chairman of SolarCity, which will now operate as a wholly owned subsidiary of Tesla).

As noted by Bloomberg, the $2 billion acquisition aims to position Tesla, primarily known to most consumers as a manufacturer of beautiful yet prohibitively pricey electric sports cars and sedans, as “one-stop shopping for consumers eager to become independent of fossil fuels.” In the near future, Tesla showrooms won’t just be places to buy and/or ogle high-end EVs. They’ll also be places where consumers can peruse solar roofing options that will help to power their homes and, of course, that Tesla Model S parked in the garage.

Noting that the tiles’ electricity-producing capabilities are “just a bonus,” Musk goes on to pose the question: “So the basic proposition will be: Would you like a roof that looks better than a normal roof, lasts twice as long, costs less and — by the way — generates electricity? Why would you get anything else?”

To be available in a quartet of styles — Slate, Tuscan, Textured Glass and Smooth Glass — that closely mimic not-so-cheap premium roofing materials, Tesla’s solar shingles are a boon for consumers who have long balked at the thought of installing rooftop solar for aesthetic reasons. (Read: big black patches that invoke the ire of the neighbors). Tesla’s shingles look just like the real deal — even nicer. “The key is to make solar look good,” said Musk during last month’s public debut of Tesla’s solar shingles, which you can watch below in its entirety. “We want you to call your neighbors over and say, ‘Check out this sweet roof.’” You can hear his pitch in more detail in the video below:

As reported by Bloomberg, while Tesla’s inoffensive-looking solar shingles are indeed considered a premium product when compared to non-solar shingles, significant savings kick in when considering the cost of shipping. Traditional roofing tiles are heavy and awkward and, as a result, cost an arm and a leg to transport. They’re also super-fragile and have a high rate of breakage. Tesla’s engineered glass shingles, on the other hand, are durable, lightweight (as much as five times lighter than conventional roofing materials) and easy to ship. The significant cost-savings associated with decreased shipping costs, as anticipated by Musk, will be passed on to consumers.

While there are skeptics who doubt that the savings gained in decreased shipping costs will render Tesla’s solar singles the most affordable option for upfront cost-focused consumers, others are embracing Musk’s claims as a potential game-changer that could potentially usher in the end of “dumb” roofing as we know it.

http://www.mnn.com/earth-matters/energy/blogs/will-tesla-solar-roofing-be-cheaper-normal-roofing

This island is powered entirely by solar panels and batteries thanks to SolarCity

On By A.P.In Kebmodee, Solar Energy, solar powerLeave a comment


Ta’u Island’s residents live off a solar power and battery storage-enabled microgrid.

by Amelia Heathman

SolarCity was applauded when it announced its plans for solar roofs earlier this year. Now, it appears it is in the business of creating solar islands.

The island of Ta’u in American Samoa, more than 4,000 miles from the United States’ West Coast, now hosts a solar power and battery storage-enabled microgrid that can supply nearly 100 per cent of the island’s power needs from renewable energy.

The microgrid is made up of 1.4 megawatts of solar generation capacity from SolarCity and Tesla and six-megawatt hours of battery storage from 60 Tesla Powerpacks. The whole thing took just a year to implement.

Due to the remote nature of the island, its citizens were used to constant power rationing, outages and a high dependency on diesel generators. The installation of the microgrid, however, provides a cost-saving alternative to diesel, and the island’s core services such as the local hospital, schools and police stations don’t have to worry about outages or rationing anymore.

“It’s always sunny out here, and harvesting that energy from the sun will make me sleep a lot more comfortably at night, just knowing I’ll be able to serve my customers,” said Keith Ahsoon, a local resident whose family owns one of the food stores on the island.

The power from the new Ta’u microgrid provides energy independence for the nearly 600 residents of the island. The battery system also allows the residents to use stored solar energy at night, meaning energy will always be available. As well as providing energy, the project will allow the island to significantly save on energy costs and offset the use of more than 109,500 gallons of diesel per year.

With concerns over climate change and the effects the heavy use of fossil fuels are having on the planet, more initiatives are taking off to prove the power of solar energy, whether it is SolarCity fueling an entire island or Bertrand Piccard’s Solar Impulse plane flying around the world on only solar energy.

Obviously Ta’u island’s location off the West Coast means it is in a prime location to harness the Sun’s energy, which wouldn’t necessarily work in the UK. Having said that, this is an exciting way to show where the future of solar energy could take us if it was amplified on a larger scale.

The project was funded by the American Samoa Economic Development Authority, the Environmental Protection Agency and the Department of Interior, whilst the microgrid is operated by the American Samoa Power Authority.

http://www.wired.co.uk/article/island-tau-solar-energy-solarcity

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

The Opportunity Rover Was Supposed To Last 90 Days. It Recently Celebrated Twelve Years On Mars

On By A.P.In Mars, Space and TimeLeave a comment

by Alfredo Carpineti

On Sunday, January 24, NASA’s Mars rover Opportunity reached 12 Earth years on the surface of Mars, having landed on the same day in 2004.

It was budgeted to last 90 days, with a lifespan of a few months, before it was thought its solar panel would be covered in dust and stop working. But thanks to a number of factors, including wind on Mars, the tenacious rover has been able to endure the harsh Martian environment for much, much longer.

The rover has begun to show its age, becoming more difficult to maneuver and having memory storage problems. Also, two of its scientific instruments have now stopped functioning completely. Problems aside, though, Opportunity continues to produce an abundance of science.

Opportunity is currently exploring a region rich in clay minerals that would have formed in wet conditions. The area is called Marathon Valley, since it’s 42 kilometers (26 miles) – the Olympic marathon distance – from Opportunity’s landing site in Eagle Crater.

“With healthy power levels, we are looking forward to completing the work in Marathon Valley this year and continuing onward with Opportunity,” Exploration Rover Project Manager John Callas said in a statement.

The rover is currently removing surface crust from rocks in the valley, and the texture and composition are being examined with the use of its robotic arm.

The Martian winter started in January, so the solar energy that the rover is currently receiving is significantly lower than usual. The team positioned the rover in a more favorable sun-facing orientation, which has increased the amount of power the solar panels are generating, allowing for power-consuming operations like drilling and rock-grinding.

“Opportunity has stayed very active this winter, in part because the solar arrays have been much cleaner than in the past few winters,” said Callas.

The rover is fully funded until the end of 2016, and the Jet Propulsion Laboratory is currently working on the next extension proposal. In the last review, Opportunity received the highest rating of any ongoing Mars mission.

http://www.iflscience.com/opportunity-s-twelve-years-red-planet

New solar power team creates supercritical steam that can drive the world’s most advanced power plant turbines

On By A.P.In Advanced Solar Steam Receiver Project, Kebmodee, Solar Energy, solar power1 Comment

A team of solar thermal engineers and scientists at the Energy Centre in Newcastle have used the ample sunlight flooding their solar fields to create what’s called ‘supercritical’ steam – an ultra-hot, ultra-pressurised steam that’s used to drive the world’s most advanced power plant turbines – at the highest levels of temperature and pressure EVER recorded with solar power.

They used heat from the sun, reflected off a field of heliostats (or mirrors) and concentrated onto a central receiver point to create the steam at these supercritical levels. The achievement is being described in the same terms as breaking the sound barrier, so impressive are its possible implications for solar thermal technology.

Put simply, the temperature of the steam they created (570° C) is about twice the maximum heat of your kitchen oven – or around the point where aluminium alloy would start melting. And the accompanying pressure (23.5 megapascals) is about 100 times as high as the pressure in your car tyres, or roughly what you’d experience if you were about 2 kilometres under the surface of the ocean.

That’s all impressive in itself. But when you take into consideration that this is the first time solar power has ever been used to create these ‘supercritical’ levels on this scale – traditionally only ever reached using the burning of fossil fuels – the real worth of this achievement begins to sink in.

Solar thermal, or concentrating solar power (CSP) power plants have traditionally only ever operated at ‘subcritical’ levels, meaning they could not match the efficiency or output of the world’s most state of the art fossil fuel power plants.

Enter the Advanced Solar Steam Receiver Project. To prove that solar thermal technology can match it with the best fossil fuel systems, they developed a fully automated control system which predicts the heat delivered from every mirror (or heliostat), allowing them to achieve maximum heat transfer, without overheating and fatiguing the receiver. With this amount of control, they were able to accurately recreate the temperature and pressures needed for supercritical success.

So instead of relying on burning coal to produce supercritical steam, this method demonstrates that the power plants of the future could be using the zero emission energy of the sun to reach peak efficiency levels – and at a cheaper price.

Thank to Kebmodee for bringing this to the attention of the It’s Interesting community.

http://csironewsblog.com/2014/06/03/our-solar-team-sets-a-hot-and-steamy-world-record/