Sunday, June 30, 2013

Halving the cost of Silicon Solar Cell research Completed

Thin Epitaxial Silicon Solar Cell Milestone Completed
Crystal Solar has completed a U.S. Department of Energy (DOE) funded Incubator project regarding technology development and manufacturing cost-effectiveness of epitaxial solar cells and modules. Thin epitaxial silicon solar cell  technology has the capability to improve the way silicon is made by eliminating many steps in the current process flow while retaining the high efficiency of mono-crystalline silicon.

They estimate this could result in reduction of module costs by approximately 50% from today's levels to ~$0.40/W, enabling the cost of solar power to become comparable to existing energy costs in most parts of the world.

During the eighteen month period of this project, Crystal Solar demonstrated multiple cell architectures which allow high-efficiency solar panels, developed and productized industrial grade production tools for the manufacture of cost-effective Epi Thin Silicon technology, and completed detailed blue prints for a 100 MW factory. Scientists from DOE's National Renewable Energy Laboratory (NREL) worked with Crystal Solar in providing overall guidance, assisting with advanced processing and metrology, and verifying the efficiency and reliability of the prototype solar panels. Crystal Solar also collaborated with Georgia Institute of Technology in the silicon solar cell processing during this project.

Crystal Solar is currently commercializing this Epi Thin-Silicon technology and plans to complete pilot production in 2013, followed by high volume manufacturing in 2014.  

Wednesday, June 26, 2013

L.A. program lets DWP pay customers to generate solar power -

L.A. program lets DWP pay customers to generate solar power -

Initially, customers generating power in the city will receive 17 cents a kilowatt-hour, a price that gradually will decline for later projects to 14 cents; projects in Owens Valley, also home to DWP ratepayers, will receive 14 cents a kilowatt-hour. Single-family homes probably won't be able to participate because most aren't large enough.
"We've acknowledged we're paying a slightly higher incentive to make absolute certain we get major players here," Nichols said. "We're starting a pioneering program. We didn't want to put out a price, hold a party and nobody comes."
Jim Jenal, founder and chief executive of rooftop solar company Run on Sun in Pasadena, said he worries the program will leave the city's nonprofits in the lurch.
Clean L.A. Solar carved out four megawatts for smaller projects, such as the North Hollywood apartment building. These can generate anywhere between 30 and 150 kilowatts per hour. The remaining 16 megawatts in the first portion of the program were reserved for large projects that can generate 150 kilowatts to 3 megawatts per hour.
Jenal said it's hard for small entities to carry the financial burden of installing and maintaining solar projects. Nonprofits are ineligible for the tax breaks that most large commercial entities use to increase the return they see off their green endeavors.
Jenal said that could hamstring a key objective of the solar program: familiarizing the public with alternative energy sources.
"What the LADWP did right is to see this as a way to get solar throughout a lot of different places in the city. It demystifies the whole concept," Jenal said. "From the stated goal, there is no place better than nonprofits — places where people come to congregate, come to learn — for them to learn about the value of sustainable energy."
Leslie of the LABC said residents and smaller organizations that can't shoulder the cost of a full solar installation can still invest as shareholders in nearby projects, and would see a return once these projects become profitable.
"We didn't want a program that would only be for a select part of the city," Leslie said. "We want to make sure that solar is diverse."
"We have sunshine over 300 days a year. The sun's free," she said, "so the better we get at harnessing it, the better off we're going to be."

Sunday, June 23, 2013

An inside look at the world's largest solar-powered boat | The Verge

An inside look at the world's largest solar-powered boat | The Verge
There's a reason why this boat stands out: last year it became the first ship to circumnavigate the globe on solar power alone. The 89,000 kg (nearly 100 ton) ship needs a massive solar array to capture enough energy to push itself through the ocean. An impressive 512 square meters (roughly 5,500 square feet) of photovoltaic cells, to be exact, charge the 8.5 tons of lithium-ion batteries that are stored in the ship's two hulls.

Thursday, June 20, 2013

Cubieboard gets a dual-core upgrade ($59 Android, Linux mini PC)

Cubieboard gets a dual-core upgrade ($59 Android, Linux mini PC)

Complete instructions on setting it up, it will load android by default, and directions are here to install berry boot to sd card, so you can run any linux flavour you like!

Friday, June 14, 2013

Unzipped nanotubes unlock potential for batteries

Unzipped nanotubes unlock potential for batteries

Rice University lab combines graphene nanoribbons with tin oxide for improved anodes 

HOUSTON – (June 13, 2013) – Researchers at Rice University have come up with a new way to boost the efficiency of the ubiquitous lithium ion (LI) battery by employing ribbons of graphene that start as carbon nanotubes.
Proof-of-concept anodes — the part of the battery that stores lithium ions — built with graphene nanoribbons (GNRs) and tin oxide showed an initial capacity better than the theoretical capacity of tin oxide alone, according to Rice chemist James Tour. After 50 charge-discharge cycles, the test units retained a capacity that was still more than double that of the graphite currently used for LI battery anodes.
The research appeared this week in the American Chemical Society journal ACS Nano­­.
Better batteries are greatly desired by everyone who carries a cellphone or computer or drives an electric car. The Rice team sees the potential for GNRs to contribute to their development.
Tour and his colleagues developed a method for unzipping nanotubes into GNRs, revealed in a 2009 cover story in Nature. Since then, the researchers have figured out how to make graphene nanoribbons in bulk and are moving toward commercial applications. One area ripe for improvement is the humble battery. In an increasingly mobile world, battery capacity is becoming a bottleneck that generally limits devices to less than a day’s worth of use.
In the new experiments, the Rice lab mixed graphene nanoribbons and tin oxide particles about 10 nanometers wide in a slurry with a cellulose gum binder and a bit of water, spread it on a current collector and encased it in a button-style battery. GNRs are a single atom thick and thousands of times longer than they are wide. The GNRs not only separate and support the tin oxide but also help deliver lithium ions to the nanoparticles.
Lab tests showed initial charge capacities of more than 1,520 milliamp hours per gram (mAh/g). Over repeated charge-discharge cycles, the material settled into a solid 825 mAh/g. “It took about two months to go through 50 cycles,” said lead author Jian Lin, a postdoctoral researcher at Rice, who believes it could handle many more without losing significant capacity.
GNRs could also help overcome a prime difficulty with LI battery development. Lithium ions tend to expand the material they inhabit, and the material contracts when they’re pulled away. Over time, materials like silicon, which shows extraordinary capacity for lithium, break down and lose their ability to store ions. Other labs at Rice have made breakthroughs that help solve the expansion problem by breaking treated silicon into a powder, achieving great capacity and many cycles.
GNRs take a different approach by giving batteries a degree of flexibility, Tour said. “Graphene nanoribbons make a terrific framework that keeps the tin oxide nanoparticles dispersed and keeps them from fragmenting during cycling,” he said. “Since the tin oxide particles are only a few nanometers in size and permitted to remain that way by being dispersed on GNR surfaces, the volume changes in the nanoparticles are not dramatic. GNRs also provide a lightweight, conductive framework, with their high aspect ratios and extreme thinness.”
The researchers pointed out the work is a “starting point for exploring the composites made from GNRs and other transition metal oxides for lithium storage applications.” Lin said the lab plans to build batteries with other metallic nanoparticles to test their cycling and storage capacities.
Co-authors of the paper are Rice graduate students Zhiwei Peng, Changsheng Xiang, Gedeng Ruan and Zheng Yan and Douglas Natelson, a Rice professor of physics and astronomy and of electrical and computer engineering. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science at Rice.
Boeing, the Air Force Office of Scientific Research, Sandia National Laboratory and the Office of Naval Research supported the research.
Read the abstract at

Wednesday, June 12, 2013

The ‘unstoppable’ renewable grid | SmartPlanet

The ‘unstoppable’ renewable grid | SmartPlanet
As I’ve detailed in previous columns, renewables have begun pushing nuclear and coal off the grid in regions where renewables provide a significant fraction of grid power. This is primarily because their priority dispatch on the grid and their generation at times of peak demand are destroying the economics of traditional “baseload” generation. But gas is a natural complement to the variable output of wind and solar, because gas-fired “peaking” plants are able to ramp up and down quickly to fill in when renewable generation fluctuates.
In order to have a grid mostly powered by renewables, it will be important for gas prices to remain competitive with coal and nuclear. At the same time, the cost of unsubsidized renewable power must continue to fall until it is competitive with fossil fuels. Several new reports find that it will reach that point in key areas by 2020.

Citigroup study

A new report by Citigroup, nicely summarized by Giles Parkinson for Renew Economy, forecasts that solar will be competitive with fossil-fueled grid power in much of the world by the end of the decade, and that “the perception of renewables as an expensive source of electricity is largely obsolete.”
The report offered two charts showing the natural gas prices at which wind and utility-scale solar are competitive with gas-fired power generation.

The wind chart plots “capacity factors” against gas prices. A capacity factor indicates the actual output of a wind farm, expressed as a percentage of the output it would have if it were running full time at full “nameplate” capacity. So, a 1 MW wind farm with a 32 percent capacity factor would produce 2,803 MWh of power per year (1 MW x 8760 hours in a year x 0.32).
EIA offers an average capacity factor for U.S. wind of 33 percent, while recent (2010-2012) estimates compiled by the National Renewable Energy Laboratory (NREL) give a median capacity factor of 38 percent for onshore wind and 39 percent for offshore wind.
In the Citi chart, wind at a 32 percent capacity factor was competitive with natural gas at about $7.50/MMBtu in 2012, and will be competitive with gas at about $6.50 by 2020. In very windy locations with capacity factors of 40 percent, wind is already competitive with gas priced below $6, and would be competitive with gas at $5 by 2020.
Put another way, both onshore and offshore wind would be cheaper than gas-fired power in the United States at a gas price of $6/MMBtu or more. Natural gas at $6 would make most of the U.S. shale gas industry profitable, and seems like a good bet for 2020, if not sooner.

For utility-scale solar, Citi cites various solar insolation factors (kWh/kW/year). Insolation factors reflect how sunny a given region is. An insolation factor of 2100 would correspond to a capacity factor of 24 percent (2100 ÷ 8,760 hours in a year). For U.S. solar PV, EIA (which skews a bit to the high side) gives an average capacity factor of 25 percent, while recent estimates compiled by NREL range from 20 to 28 percent.

Tuesday, June 4, 2013

Solar Kettle allows for boiling water off the grid

Solar Kettle allows for boiling water off the grid —A company called Contemporary Energy has unveiled a new device it calls the Solar Kettle. It looks very much like a normal coffee thermos, but has flaps on one side that open to allow for collecting solar energy, thus heating whatever is held inside. The company will be marketing the device to campers and others that need a way to boil water when electricity is not available.
The Solar Kettle looks very much like a normal thermos when not in use, though it's heavier—2.6 pounds when empty, compared to about a half pound for a normal thermos. It looks markedly different however when heating a liquid. The flaps open and direct the sun's energy to the vacuum sealed thermos. The device comes with a stand as well to allow for unattended heating. It typically takes about two hours to heat to boiling. The Kettle can also be used to brew tea, melt snow or to boil water to make it safe to drink. And if the need arises, it can even be used to desalinate .
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Devices that can make tainted water safe to drink have become increasingly popular as have spread the word about the risks posed to people around the world who don't have access to clean drinking water. While the Solar Kettle is not directed towards such end users, it's clear it could very easily be used for that purpose. The device holds 17 ounces of liquid, which is enough to make three cups of tea. That means it's capable of providing enough safe drinking water for one person, indefinitely. Of course that only applies on days when the sun is shining.
Reps for the new device point out that their Solar Kettle can also be used to heat soup, or even to boil . That makes it ideal, they say, for hikers, campers or anyone else who wants to boil water without going to the trouble of setting up a campfire. They note also that the exterior of the device remains cool to the touch during heating, preventing users from getting burned—and because it's heavily insulated, water once heated, will remain that way for several hours.

Monday, June 3, 2013

Solar Industry Anxious Over Defective Panels -

Solar Industry Anxious Over Defective Panels -
Executives at companies that inspect Chinese factories on behalf of developers and financiers said that over the last 18 months they have found that even the most reputable companies are substituting cheaper, untested materials. Other brand-name manufacturers, they said, have shut down production lines and subcontracted the assembly of modules to smaller makers.
“We have inspectors in a lot of factories, and it’s not rare to see some big brands being produced in those smaller workshops where they have no control over quality,” said Thibaut Lemoine, general manager of STS Certified, a French-owned testing service. When STS evaluated 215,000 photovoltaic modules at its Shanghai laboratory in 2011 and 2012, it found the defect rate had jumped from 7.8 percent to 13 percent.
In one case, an entire batch of modules from one brand-name manufacturer listed on the New York Stock Exchange proved defective, Mr. Lemoine said. He declined to identify the manufacturer, citing confidentiality agreements.
“Based on our testing, some manufacturers are absolutely swapping in cheap Chinese materials to save money,” Jenya Meydbray, chief executive of PV Evolution Labs, a Berkeley, Calif., testing service.
SolarBuyer, a company based in Marlborough, Mass., discovered defect rates of 5.5 percent to 22 percent during audits of 50 Chinese factories over the last 18 months, said Ian Gregory, the company’s senior marketing director.
Some Chinese manufacturers acknowledge that quality has become a problem
“There are a lot of shortcuts being taken, and unfortunately it’s by some of the more reputable companies and there’s also been lot of new companies starting up in recent years without the same standards we’ve had at Suntech,” said Stuart Wenham, the chief technology officer of Suntech, which is based in Jiangsu Province in eastern China.
When asked about quality standards, Trina Solar, one of the largest Chinese manufacturers, said in an e-mailed response, “For Trina, quality will not be compromised in our cost-reduction efforts.”
The heart of a solar panel is a photovoltaic cell that generates electricity when struck by sunlight. Among the most critical components are a thin film that protects the cell from moisture, and the encapsulant that seals the cell between layers of glass.
Mr. Gregory said repeat inspections of factories found some manufacturers had been constantly switching to cheaper materials, including some whose use-by date had expired.
“If the materials aren’t good or haven’t been thoroughly tested, they won’t stick together and the solar module will eventually fall apart in the field,” he said.
That’s what happened in 2011 at a year-old Australian solar plant, Mr. Meydbray of PV Evolution said. Testing confirmed that substandard materials were causing the Chinese-made modules’ protective coating to degrade, he said. The power plant operator declined to be identified.
“I think quality is increasingly a concern, but it’s not a major issue yet,” said Rhone Resch, chief executive of the Solar Energy Industries Association, a trade group. “As companies race to cut their costs, some who are on the edge may take short cuts.”
The Energy Department’s National Renewable Energy Laboratory has studied the performance of solar panels up to 2010, according to Sarah Kurtz, a scientist who manages the laboratory’s photovoltaic reliability group.
“The question is whether things are deteriorating rapidly or whether it’s a few isolated companies not doing so well on their quality control,” she said. “I hear a lot of angst, but I haven’t seen a lot of solid information.”
All solar panels degrade and gradually generate less electricity over time. But a review of 30,000 installations in Europe by the German solar monitoring firm Meteocontrol found 80 percent were underperforming. Testing of six manufacturers’ solar panels at two Spanish power plants by Enertis Solar in 2010 found defect rates as high as 34.5 percent.
Enfinity operates solar installations in Europe and the United States. Bob Hopper, Enfinity’s chief development officer, said his company had stopped buying Chinese modules because of quality concerns. “Even a small amount of unforecasted degradation in electricity production can have significant economic impact on us,” he said.
In the Netherlands, René Moerman, chief strategy officer of Solar Insurance and Finance, said claims had risen 15 percent recently. He said an inspection of a solar plant in Britain in March revealed that 12 percent of the newly installed Chinese-made modules had failed. He said confidentiality agreements prevented him from naming the manufacturer.
Other solar developers and installers said they had not experienced quality problems.
“The systems we installed in 2012 had the best performing year yet,” said Lyndon Rive, chief executive of SolarCity, the largest residential solar installer in the United States and a buyer of panels from China’s Yingli Solar and Trina.
Non-Chinese manufacturers have had quality problems as well. The defective panels installed on the Los Angeles area warehouse, for instance, were made by an American manufacturer. A reporter was granted access to the project on the condition that the parties’ identities not be disclosed because of a confidential legal settlement.
First Solar, one of the United States’ biggest manufacturers, has set aside $271.2 million to cover the costs of replacing defective modules it made in 2008 and 2009.
Nor are all solar developers shunning Chinese manufacturers. The United States subsidiary of Yingli, the world’s largest solar panel maker since 2012, won a contract last year to supply solar panels for a California power plant.
“The one thing I can tell you is that Yingli does not cut corners,” said Brian Grenko, vice president for operations at Yingli Americas, adding that only 15 defective modules had been returned to the company out of 2.8 million shipped to the United States since 2009.
Still, Yingli executives acknowledge that quality has become a competitive issue.