Archive for the ‘solar power’ Category

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

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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.

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/

<img src=https://itsinterestingdotcom.files.wordpress.com/2014/01/living-off-the-grid.jpg&#8221; alt=”living off the grid” width=”614″ height=”429″ class=”aligncenter size-full wp-image-7407″ />

At a time when we carry computers in our pockets and our cars practically do the driving for us, a certain subset of people have willingly chosen to cut the cord on modern American life — for good.

Off-the-grid living — that is, using natural resources like sun and wind power to provide amenities like heat and electricity — has become commonplace in places like Terlingua, an isolated community in Southwest Texas. What was once a bustling mining town is now a veritable ghost town, tucked into the foothills of Big Bend National Park in the north Chihuahuan desert.

To Abe Connally, 34, it was the perfect place to go off the map. In 2002, Connally moved to Terlingua, leaving behind a lucrative job as a web designer in Austin, Texas in order to try his hand at rural life.

“I’ve always enjoyed rural life, and the thought of sustainability and home-scale energy production intrigued me,” says Abe, who grew up in New Mexico and Texas. “On top of that, I wanted to see how integrating systems to reduce waste and improve efficiency would affect the architecture and other components of this lifestyle.”

Within a year, he met and married his wife, Josie, a British expat who was raised in Africa, Portugal and England before she finally settled out West. They never questioned whether to build their own home or not. It was only a matter of finding the right land and the right resources.

“When we started building our first home, we figured that if we could build a sustainable homestead from scratch in the desert, then we could do it anywhere,” Josie says. “We realized that if we could reduce our needs and resources, our lifestyle would be cheaper to maintain, giving us money to save or invest.”

More than a decade, two hand-built homes and a pair of energetic sons later, they’ve dedicated their lives to maintaining their sustainable home, using their blog VelaCreations to teach others how to follow in their footsteps.

Here’s what it’s like to live really off-the-grid:

“When we built our first home, we had almost no money,” Josie says. “We bought 20 acres of pristine desert land for $1,000 and moved an old bus onto it. The bus — retrofitted with a bed, small stove, solar panel and batteries, etc. — was our home until we could build a better quality one.”

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Neither Abe nor Josie were particularly experienced home builders — far from it. They relied on books, blogs and online tutorials to learn everything from bricklaying to building solar panels for energy.

Abe: “[Renowned architect] Michael Reynolds introduced us to the concepts of architecture as a group of integrated systems. From passive solar designs to using waste as construction materials, his books showed us that it was possible to live like we wanted to.”

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They built their first sustainable home in 2002 near Terlingua, but they were 30 miles from the closest schools and hospitals — not exactly ideal for raising small children. In 2007, they moved closer to town and started constructing home No. 2.

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Like their own personal Rome, their new home took years to complete and is a constant work in progress.

Abe: “We added to each system as we could afford it, in other words, little by little. For the house itself, we used adobe, mixing the mud with our feet and putting it into forms (made from scrap materials) straight on the walls. It took a long time, but cost almost nothing.”

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For off-the-gridders, the sun is crucial. The Connallys rely on solar power for all of their heat and electricity (with help from a homemade wind generator).

“The house is partially buried in a south-facing hill [and] the thermal mass of the hill helps to keep a constant temperature inside the house year-round, like a cave,” Abe explains. “The house stays about 70 degrees for most of the year.”

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Abe: “Our water is collected from the roof. We live in a desert, so rainfall is limited, and the majority of our rain comes from July through September. We store this water in large tanks we make ourselves and then filter for domestic use.”

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“The first part of off-grid living is to conserve, and reduce your needs, so that it’s easier to produce your necessities for yourself,” Abe says. By using a composting toilet, which requires no water, they cut down on waste and fertilize their land at the same time.

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The interior has a modern feel, with hand-laid brick floors and painstakingly carved entryways.

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Their $9,600 annual budget is planned down to the dollar. They earn a small income through Abe’s web consulting business and some freelance writing, but their farm is their real paycheck.

When they decided to rebuild, they sought out more fertile land with enough rainfall to sustain a garden and livestock.

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As a family, they bring new meaning to the term “farm to table”:

“We’ve had tomato plants that produce for several years, and they become these jungles of fresh food right in the dining room,” Abe says. “In fact, our youngest son, Nico, will sit there and eat every red tomato he can reach, but if you put one on his plate, he refuses to touch it.”

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Josie: “We grow a wide variety of things, depending on our tastes at the time. We regularly grow tomatoes, strawberries, peppers, okra, cucumbers, squash, corn, sunflowers, melons, greens, roots and several herbs. We also have a few fruit trees (plums, apricots, peaches).”

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“There is no food fresher than that, and it’s something you get kind of used to,” she says.

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They’ve even got a tiny village of beehives for fresh honey.

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Meat is also on the menu. The Connallys have gradually raised a menagerie of livestock, including pigs, rabbits, guinea pigs, and chickens. It’s vastly cheaper than purchasing their meat from stores.

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One of their pigs just had a litter.

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They’re cute now, but eventually they’ll be sold in the village or, more often than not, wind up on the dinner menu. The Connallys have become quite the bacon connoisseurs.

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Everyone lends a hand in the family harvest.

Josie: “The kids collect eggs and feed all the poultry. We feed the rabbits, pigs and all the other little critters. We then all go look at any baby rabbits and the kids often get out their guinea pigs to play with.”

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Nothing goes to waste.

Josie: “We sell any surplus. We often have extra meat (especially rabbit), which we sell locally. We also sell eggs, as well as trading them for raw milk. Any vegetables and such we tend to preserve (drying, canning, kimchi) as we don’t yet grow enough to fill our yearly needs.”

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Even rabbit fur gets turned into cozy hats and slippers.

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Josie: “Right now, we’re spending about $800 a month: $100 on fuel, $500 on [feed for the animals], groceries and other household items, and $100 on Internet and phone. We also continue to improve our homestead, which costs a little extra, depending on the task at hand.”

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Their bedrooms are cozy and get a lot of natural light, which helps them conserve electricity.

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Abe: “I think there’s a certain pride that comes from being able to say ‘I made that’. We are surrounded by things we’ve made ourselves, including our home and energy infrastructure.”

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With two kids under the age of 5, the Connallys admit they’ve made some allowances in their off-grid lifestyle. They have games for game nights and keep a healthy stock of books and DVDs for entertainment.

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But, naturally, they spend most of their free time outdoors.

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They keep a car handy for trips to town and to cart the kids to and from school each day. Their goal this year is to get their car running on natural fuel supplies.

Josie: “We live about a 20-minute drive from a small village, where there’s a kindergarten, primary school, clinic and a couple of basic stores. That’s actually one of the main reasons we moved here before starting a family: still very rural, but with everything needed for small kids.”

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The kids seem to dig it.

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Laundry gets done the old-fashioned way.

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Sunlight and fresh air are all the dryer they’ll ever need.

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It’s always nice to have relatives visit, like the kids’ grandparents.

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Josie: “We’re in constant contact with family and friends over the Internet (huge fans of Skype and the like). However, visits are unfortunately much less frequent. If we ever get around to building the blimp we’ve always wanted, we’ll be sure to stop by a lot more often.”

Abe: “We’ve been able to save a few years worth of income, but also, because of our lifestyle, we don’t have to earn as much. So instead of working 40-hour weeks for money, we work 5-10 hours a week. This gives us enough for savings and expenses. The real value is the 30 hours a week we gain.”

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Abe: “It took a long time, but cost almost nothing. That was 12 years ago and we are still amazed by how far we’ve come since then.”

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To see more from the Connallys’ off-the-grid home, check out their blog, VelaCreations: http://velacreations.com/

Read more: http://finance.yahoo.com/news/family-life-off-the-grid-abe-connally-vela-creations-144054081.html

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

desert farming

A project to “green” desert areas with an innovative mix of technologies—producing food, biofuel, clean water, energy, and salt—reached a milestone this week in the Gulf state of Qatar. A pilot plant built by the Sahara Forest Project (SFP) produced 75 kilograms of vegetables per square meter in three crops annually, comparable to commercial farms in Europe, while consuming only sunlight and seawater. The heart of the SFP concept is a specially designed greenhouse. At one end, salt water is trickled over a gridlike curtain so that the prevailing wind blows the resulting cool, moist air over the plants inside. This cooling effect allowed the Qatar facility to grow three crops per year, even in the scorching summer. At the other end of the greenhouse is a network of pipes with cold seawater running through them. Some of the moisture in the air condenses on the pipes and is collected, providing a source of fresh water.

One of the surprising side effects of such a seawater greenhouse, seen during early experiments, is that cool moist air leaking out of it encourages other plants to grow spontaneously outside. The Qatar plant took advantage of that effect to grow crops around the greenhouse, including barley and salad rocket (arugula), as well as useful desert plants. The pilot plant accentuated this exterior cooling with more “evaporative hedges” that reduced air temperatures by up to 10°C. “It was surprising how little encouragement the external crops needed,” says SFP chief Joakim Hauge.

The third key element of the SFP facility is a concentrated solar power plant. This uses mirrors in the shape of a parabolic trough to heat a fluid flowing through a pipe at its focus. The heated fluid then boils water, and the steam drives a turbine to generate power. Hence, the plant has electricity to run its control systems and pumps and can use any excess to desalinate water for irrigating the plants.

The Qatar plant has also experimented with other possibilities such as culturing heat-tolerant algae, growing salt-tolerant grasses for fodder or biofuel, and evaporating the concentrated saline the plant emits to produce salt.

The Qatar plant—which is supported by Qatari fertilizer companies Yara International and Qafco—is just 1 hectare in extent with 600 square meters of growing area in the greenhouse. The fact that this small greenhouse produced such good yields, Hauge says, suggests that a commercial plant—with possibly four crops a year—could do even better. SFP researchers estimate that a facility with 60 hectares of growing area under greenhouses could provide all the cucumbers, tomatoes, peppers, and egglants now imported into Qatar. The results “reveal the potential for enabling restorative growth and value creation in arid land,” Hauge says. “I personally think that it is very important that people promote and invest in these ideas. Protected agriculture (I call it “indoor food production”) is an important option for the desert areas, particularly in the Middle East,” says Richard Tutwiler, director of the Desert Development Center at the American University in Cairo. “The big question is economic feasibility. How much did it cost to produce 75 kg of cucumbers per square meter?”

SFP is now engaged in studies aimed at building a 20-hectare test facility near Aqaba in Jordan. “This will be a considerable scaling up from the 1 hectare in Qatar,” Hauge says, and big enough to demonstrate commercial operation.

http://news.sciencemag.org/asiapacific/2013/11/desert-farming-experiment-yields-first-results

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

solar power

Outside Phoenix, Ariz., on Wednesday, a power company turned on one of the largest solar power plants of its kind in the world. But unlike other solar farms, this plant continues giving power to 70,000 Arizona households long after the sunset.

The Solana plant uses 3,200 mirrors that are tilted so they focus the sun’s rays to heat a specially-designed oil. That boils water, which drives turbines and generates electricity. Or, the oil can heat giant tanks of salt, which soak up the energy. When the sun goes down, or when households need more power, the hot salt tanks heat up the oil, which again boils water to drive the turbines.

Whereas conventional solar panels only give power when the sun is up, these giant salt batteries give renewable energy on demand. They can store six hours-worth of energy, which can meet the demands of Arizona customers, according to months of test data.

“That’s the sort of thing you can do with a conventional gas plant that no one had envisioned doing with renewables,” says Patrick Dinkel, vice president of resource management for Arizona Public Service, which is Arizona’s largest utility company.

The company has already bought the power from this plant for the next 30 years, to add to the state’s goal of generating 15 percent of its energy from renewable sources by 2025. The plant does mean higher energy bills for APS customers — an extra $1.28 per month for the first five years, $1.09 per month for the next five, and then 94 cents per month after that, according to the company. Dinkel says the state won’t see a lot more of these plants soon because that would cost too much.

“Right now natural gas wins that race (for cheap power,)” Dinkel says. “The challenge is no one knows what those economics look like in five years.”

The U.S. Department of Energy lent Abengoa Solar, the Spanish company that built that plant as well as Europe’s first solar thermal power plant, $1.4 billion, out of the $2 billion price tag. It’s the same program that financed Solyndra, a solar panel firm that went bankrupt in 2011. But this is a different kind of investment, says Armando Zuluaga, general manager of Abengoa Solar. He points out the company already has a public utility buying their output for the next 30 years, so the government will get its money back with interest.

“There’s no market risk here,” Zuluaga says. “It’s just about getting the plant built.”

This won’t be the last we hear of Abengoa Solar and this technology. The company is building a similar, though smaller plant in the Mojave desert in California, which will come online next year, as well as plants in South Africa.

http://www.npr.org/blogs/thetwo-way/2013/10/11/232348077/in-ariz-a-solar-plant-that-powers-70-000-homes-day-or-night

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

solar cell

German Fraunhofer Institute for Solar Energy Systems, Soitec, CEA-Leti and the Helmholtz Center Berlin announced today that they have achieved a new world record for the conversion of sunlight into electricity using a new solar cell structure with four solar subcells. Surpassing competition after only over three years of research, and entering the roadmap at world class level, a new record efficiency of 44.7% was measured at a concentration of 297 suns. This indicates that 44.7% of the solar spectrum’s energy, from ultraviolet through to the infrared, is converted into electrical energy. This is a major step towards reducing further the costs of solar electricity and continues to pave the way to the 50% efficiency roadmap.

Back in May 2013, the German-French team of Fraunhofer ISE, Soitec, CEA-Leti and the Helmholtz Center Berlin had already announced a solar cell with 43.6% efficiency. Building on this result, further intensive research work and optimization steps led to the present efficiency of 44.7%.

These solar cells are used in concentrator photovoltaics (CPV), a technology which achieves more than twice the efficiency of conventional PV power plants in sun-rich locations. The terrestrial use of so-called III-V multi-junction solar cells, which originally came from space technology, has prevailed to realize highest efficiencies for the conversion of sunlight to electricity. In this multi-junction solar cell, several cells made out of different III-V semiconductor materials are stacked on top of each other. The single subcells absorb different wavelength ranges of the solar spectrum.

“We are incredibly proud of our team which has been working now for three years on this four-junction solar cell,” says Frank Dimroth, Department Head and Project Leader in charge of this development work at Fraunhofer ISE. “This four-junction solar cell contains our collected expertise in this area over many years. Besides improved materials and optimization of the structure, a new procedure called wafer bonding plays a central role. With this technology, we are able to connect two semiconductor crystals, which otherwise cannot be grown on top of each other with high crystal quality. In this way we can produce the optimal semiconductor combination to create the highest efficiency solar cells.”

“This world record increasing our efficiency level by more than 1 point in less than 4 months demonstrates the extreme potential of our four-junction solar cell design which relies on Soitec bonding techniques and expertise,” says André-Jacques Auberton-Hervé, Soitec’s Chairman and CEO. “It confirms the acceleration of the roadmap towards higher efficiencies which represents a key contributor to competitiveness of our own CPV systems. We are very proud of this achievement, a demonstration of a very successful collaboration.”

“This new record value reinforces the credibility of the direct semiconductor bonding approaches that is developed in the frame of our collaboration with Soitec and Fraunhofer ISE. We are very proud of this new result, confirming the broad path that exists in solar technologies for advanced III-V semiconductor processing,” said Leti CEO Laurent Malier.

Concentrator modules are produced by Soitec (started in 2005 under the name Concentrix Solar, a spin-off of Fraunhofer ISE). This particularly efficient technology is employed in solar power plants located in sun-rich regions with a high percentage of direct radiation. Presently Soitec has CPV installations in 18 different countries including Italy, France, South Africa and California.

http://phys.org/news/2013-09-world-solar-cell-efficiency.html

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