Monday, September 01, 2014

Airbus Moves Forward With Unmanned Solar Powered "Pseudo-Satellite"

It takes chutzpah to tweet “rockets are tricky” shortly after one you have just launched has deliberately blown itself up. But Elon Musk, founder and boss of SpaceX, is not a man who lacks self-confidence, and he did just that on Aug. 22 after the terminal malfunction of one of his company’s Falcon 9 vehicles.

That Arianespace, a French rival of SpaceX, announced on the same day that two satellites it had tried to launch to join the European Space Agency’s Galileo constellation (intended to rival America’s Global Positioning System), had entered a “non-nominal injection orbit” — in other words, gone wrong — shows just how difficult the commercialization of space can be.

If spacecraft are so precarious, then perhaps investors should lower their sights. But not in terms of innovation; rather in altitude. Airbus, a European aerospace company, thinks that developing satellite-like capabilities without satellites is the answer. Hence the firm’s recent trial, at an undisclosed location (but one subject to Brazilian airspace regulations) of Zephyr 7, a high-altitude “pseudo-satellite,” or HAPS for short.

Zephyr (named after the Greek god of the west wind) is actually an unmanned, ultralight, solar-powered, propeller-driven aircraft. But it is designed, just as some satellites are, to hover indefinitely over the same part of the world. With a 23-metre wingspan and a weight of only 50 kilograms, it is fragile and must remain above the ravages of the weather and the jetstream both by day and by night. It therefore flies at an altitude of around 21 kilometres during daylight hours, and then glides slowly down to around 15 kilometres when the sun is unavailable to keep it aloft.

Its solar cells, which are mounted on its wings, produce 1 kilowatt for every kilogram of panel. That power is fed into lithium-sulphur rechargeable batteries which can store 350 watt-hours per kilogram. (For comparison, the lithium-polymer batteries in iPhones store around 200 watt-hours per kilogram.) The result is a plane that can, potentially, stay aloft for months, though its longest test-run so far is a mere two weeks.

The Zephyr team achieved all this by following the principle of “adding lightness” — jettisoning anything that did not help make the aircraft fly higher and longer. That included the undercarriage. But Zephyr weighs so little and travels so slowly (about 12 knots as it approaches the runway) that its landing is little more than a scrape.

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Sunday, August 31, 2014

Controlled Crystals Make Perovskite Solar Cells Practical

From MIT TechnologyReview

A new way to control the growth of crystalline materials called perovskites could lead to commercial solar cells that hit a sweet spot of high performance and low cost. Although individual perovskite cells have achieved promising results in the lab, until now it hasn’t been clear how they might be made in uniform batches.

Certain perovskites can harvest the energy of sunlight very efficiently because they strongly absorb both visible and infrared light. And unlike silicon films, which are made at high temperatures, perovskite films can be made from solution at much lower temperatures. It should be possible to make perovskite solar cells using low-cost, low-energy methods such as printing.

The first perovskite cells were made in 2009, but the best can already convert 17.9 percent of the energy in sunlight into electricity. That’s starting to be competitive with commercial thin-film cells like cadmium telluride and silicon, says Timothy Kelly, a chemist at the University of Saskatchewan in Saskatoon, Canada.

However, it has proven difficult to make high quality perovskite solar cells consistently. In the batches made so far there is a wide variation in how effectively individual cells can convert light into electricity. “When you make 10 different perovskite cells, you get 10 different efficiencies,” says Prashant Kamat, a chemist at the University of Notre Dame in Indiana. “It’s frustrating.”

The problem is caused by variation in the size of the crystals in different cells. To electrons in a solar cell, the boundaries between crystals are like walls, so larger crystals offer fewer impediments to the flow of electricity. New research published today in the journal Nature Nanotechnology could provide a way to solve that issue by showing how to control the growth of perovskite crystals.

The perovskite being developed for solar cells has an ingredient list that includes a hydrocarbon, ammonia, lead, and iodine. There are many perovskites—the name refers to the crystal structure of these materials—but this particular one is most promising for use in solar cells. The crystals are made in a two-step process that begins with coating a surface with lead iodide solution and allowing it to dry out. Then the surface is coated with a solution of methyl ammonium iodide. As that dries out, compounds from the two layers come together to form perovskite crystals.

Michael Grätzel, a chemist at the École Polytechnique Fédérale de Lausanne, Switzerland, and Nam-Gyu Park, a chemist at Sungkyunkwan University in Korea, have now worked out a recipe for taking control of that process. They found that by carefully controlling the concentrations of the starting solutions, and other processing conditions, they could consistently make perovskite films with the larger crystals needed for an efficient solar cell.

The Swiss and Korean groups used these methods to make perovskite solar cells with an average efficiency of 16.4 percent, and very little variation in efficiency between different cells.

Park says that now that it’s possible to make high-quality perovskite reliably, it’s time to deal with other problems with the material. One is that humidity causes the materials to break down and leak methyl ammonium. Park says that researchers either need to find a way to seal perovskite solar cells against humidity or find new versions of the materials. Another problem is that the materials are made using lead, which is toxic.

“Having learned from these materials, we should move to others, because lead is not environmentally benign, and this material is not stable,” says Mercouri Kanatzidis, a chemist at Northwestern University in Illinois. He and Northwestern materials scientist Robert Chang have been developing a lead-free perovskite that substitutes tin. It currently only converts light into electrical power with an efficiency of 6 percent. But they’re both optimistic, pointing to how the lead-based materials improved rapidly from about 3 percent in 2009 to about 18 percent today.

Meantime, Grätzel believes that the existing materials haven’t hit their upper performance limits yet. “I think 20 percent efficiency should be possible in the near term,” he says.

Friday, August 29, 2014

Fluor Completes 170-Megawatt Centinela Solar Energy Facility in Southern California

IRVING, TX--(eSolarEnergyNews)--Fluor  has completed the engineering, procurement, construction and commissioning for both phases of LS Power’s new Centinela Solar Energy Facility, one of the largest of its kind in the United States. Located near El Centro, California, the 170-megawatt photovoltaic solar project will provide clean, renewable energy in the southwestern U.S.

“The successful completion of this large solar facility is the result of a long-standing relationship and effective coordination between LS Power and Fluor,” said Matt McSorley, president of Fluor’s Power business. “We are especially proud of the project team’s exemplary health, safety and environmental record.”

“Fluor deserves to be congratulated for its successful completion of construction on the Centinela Solar Energy Facility,” said John King, executive vice president of LS Power. “Having achieved this important milestone, Centinela will serve California and the region with clean, renewable energy for decades to follow.”

Fluor provided the engineering and procurement services for the lump-sum project from its southern California operations center. LS Power and Fluor broke ground on the new facility in December 2012.

The construction of the renewable energy project provided hundreds of jobs to workers in the Imperial Valley region of southern California. The construction team installed a total of more than 875,000 solar photovoltaic panels on the 1,600-acre site. Fluor completed the project safely, working more than 700,000 construction hours with no lost-time accidents. In addition to providing engineering, procurement and construction services, Fluor will also operate and maintain the world-class facility for the next five years.

The Centinela facility is the second major solar plant that Fluor has designed and built for LS Power. In November 2013, Fluor announced the completion of the 125-megawatt Arlington Valley Solar Energy II facility in Maricopa County, Arizona.

LS Power is an independent power company that develops, owns, operates and invests in power generation and electric transmission infrastructure throughout the United States.

Wednesday, August 27, 2014

OneRoof Energy Announces Investment Fund

SAN DIEGO, CA --(eSolarEnergyNews)--  OneRoof Energy, Inc., a residential solar services provider and wholly-owned subsidiary of OneRoof Energy Group, Inc. (TSXV:ON) announced today that it has reached an agreement with an unrelated third-party securing equity for a $58 million residential solar financing fund that will support an estimated portfolio of more than 2,000 residential solar power purchase agreements to be originated over the next 12 months initially in California, Hawaii, Massachusetts and New York.  The partnership expects to recognize investment tax credits under the American Recovery and Reinvestment Act of 2009.

"We are committed to expanding solar solutions to more homeowners," commented Dale A. Vander Woude, Executive Vice President – Capital Markets for OneRoof Energy.  "This new financing partnership enables us to provide a significantly more efficient sales and installation process by simplifying the financing and equipment requirements."

The new fund brings together parties with a common belief in distributed generation in a financial structure that takes advantage of the strengths of the relevant parties.  OneRoof will invest in the partnership, and remain the primary point of contact with the homeowner for the life of the transaction as operations and maintenance provider.

"One of the many benefits of this new residential solar fund is attracting additional sales channel partners by providing new sources of capital and increasing their sales capacity," added Vander Woude.

OneRoof Energy anticipates that the fund will be fully deployed within 12 months, and looks forward to developing a long-term, multi-investment relationship with its new partner.

About OneRoof Energy
OneRoof Energy Group, Inc. (TSXV: ON), operating through its US subsidiary, OneRoof Energy, Inc., is a complete solar services provider offering homeowners everything from traditional and lease financing, PPAs, solar system design and installation project management to ongoing system monitoring and maintenance services. Utilizing its technology-rich, solar leasing fulfilment platform, OneRoof Energy is partnering with traditional energy retailers and home services companies of all sizes to offer residential customers affordable, renewable energy choices.   With its unique end-to-end energy solution, the company has created multiple touch points to offer cost-saving energy products and services that create a seamless experience for the homeowner while fulfilling their unique energy needs.  Currently, the company serves residential customers in five states including Arizona, California, Hawaii, Massachusetts and New York with plans for additional expansion. For more information, visit

Yingli Green Energy to Supply 66 MWp of PV Modules to Push Energy for Four Large-scale Projects in the United Kingdom

BAODING, CHINA --(eSolarEnergyNews)--  Yingli Green Energy, the largest vertically integrated photovoltaic ("PV") module manufacturer in the world, known as "Yingli Solar," today announced that it has partnered with renewable energy developer Push Energy Ltd. ("Push Energy") to supply Yingli Solar's multicyrstalline modules for four large-scale PV power plants in the United Kingdom ("U.K.").

The four sites will collectively have a clean, renewable electricity capacity of up to 66 MWp and will be located in East Anglia, U.K. The projects will be completed by February 2015. Push Energy works with landowners, local stakeholders, planners and the power networks to supply renewable, green power into the grid for local use. The company has a strong background in farming and conservation management and selects sites that have minimum visual impact with appropriate landscaping.

"Solar PV farms have an important role to play in the U.K.'s long-term energy security. Working with strong partners such as Yingli Green Energy is critical to our vision for the future. The company has provided invaluable support and hands-on practical advice which has allowed us to complete all projects to a very tight time schedule," said Mr. Jason Wallis, Finance Director of Push Energy.

"We are thrilled to work with Push Energy in Europe's largest and most promising solar market to date," said Mr. Liansheng Miao, Chairman and Chief Executive Officer of Yingli Green Energy. "We are committed to working with well-established companies with a solid project pipeline such as Push Energy. It also supports our long-term commitment to the U.K. market where we see sustainable growth potential in the coming years."

About Yingli Green Energy

Yingli Green Energy Holding Company Limited (NYSE: YGE), known as "Yingli Solar," is the world's largest photovoltaic module manufacturer in terms of production capacity and shipments. Yingli Green Energy's manufacturing covers the photovoltaic value chain from ingot casting and wafering through solar cell production and module assembly. Headquartered in Baoding, China, Yingli Green Energy has more than 30 regional subsidiaries and branch offices and has distributed more than 10,000 MW of PV modules to customers worldwide. For more information, please visit and join the conversation on Facebook, Twitter and Weibo.

About Push Energy

Push Energy is a renewable energy developer currently specializing in rural solar farming. The team of experts will control the site selection, plant development and provision of operational and maintenance support for the 25 year life of the project, ensuring that plants are maintained to optimize both energy generation and environmental benefit of the site.

Push Energy works with the landowners, local communities, planners and the power networks to supply renewable, green solar power into the grid, much of which will meet local demand.

Push Energy has a subsidiary Push Build, which acts as an Engineering Design and Procurement Contractor (EPC). Being an EPC enables the Push Energy group to keep control of the build process of sites, notably the timing of delivery, and ensures that the quality of work completed is maximized. Push Energy's management have deep roots in the East Anglian farming community and this background allows them an understanding of the needs of farmers and farmland. For more information please visit