Solar Power Thread

[M II A II R II K]

Solar power generation around the clock


November 5, 2009

by Lin Edwards

http://www.physorg.com/news176632405.html

(PhysOrg.com) -- A Californian company, SolarReserve, is developing a solar power system that can store seven hours' worth of solar energy by focusing mirrors onto millions of gallons of molten salt, allowing the plant to provide electricity 24 hours a day.

- The solar energy is stored using a massive circular array of up to 17,500 mirrors (heliostats), each measuring 24 by 28 feet and attached to a 12-foot pedestal. The heliostat field encircles a concrete Solar Power Tower 538 feet high, with a 100-foot high receiver on top, which holds 4.4 million gallons of molten salt. When the heliostats focus the sunlight onto the receiver the salt is heated to over 1,000 degrees Fahrenheit.

[M II A II R II K]

• Video Link

[M II A II R II K]

Japan eyes solar station in space


Sun Nov 8, 6:20 am

by Karyn Poupee

http://news.yahoo.com/s/afp/20091108...olartechnology

TOKYO (AFP) – It may sound like a sci-fi vision, but Japan's space agency is dead serious: by 2030 it wants to collect solar power in space and zap it down to Earth, using laser beams or microwaves.

- With few energy resources of its own and heavily reliant on oil imports, Japan has long been a leader in solar and other renewable energies and this year set ambitious greenhouse gas reduction targets.

- But Japan's boldest plan to date is the Space Solar Power System (SSPS), in which arrays of photovoltaic dishes several square kilometres (square miles) in size would hover in geostationary orbit outside the Earth's atmosphere.

[M II A II R II K]

New Nanowires May Contribute To Highly Efficient Solar Cells


Nov. 13, 2009

http://www.sciencedaily.com/releases...1111122320.htm

Danish nanophysicists have developed a new method for manufacturing the cornerstone of nanotechnology research -- nanowires. The discovery has great potential for the development of nanoelectronics and highly efficient solar cells.

- "We have changed the recipe for producing nanowires. This means that we can produce nanowires that contain two different semiconductors, namely gallium indium arsenide and indium arsenide. It is a big breakthrough, because for first time on a nanoscale, we can combine the good characteristics of the two materials, thus gaining new possibilities for the electronics of the future," explains Peter Krogstrup.

[M II A II R II K]

Hidden Solar Cells: 3-D System Based On Optical Fiber Could Provide New Options For Photovoltaics


Nov. 3, 2009

http://www.sciencedaily.com/releases...1102172517.htm

Converting sunlight to electricity might no longer mean large panels of photovoltaic cells atop flat surfaces like roofs.

- Using zinc oxide nanostructures grown on optical fibers and coated with dye-sensitized solar cell materials, researchers at the Georgia Institute of Technology have developed a new type of three-dimensional photovoltaic system. The approach could allow PV systems to be hidden from view and located away from traditional locations such as rooftops.

- "Using this technology, we can make photovoltaic generators that are foldable, concealed and mobile," said Zhong Lin Wang, a Regents professor in the Georgia Tech School of Materials Science and Engineering. "Optical fiber could conduct sunlight into a building's walls where the nanostructures would convert it to electricity. This is truly a three dimensional solar cell."

[M II A II R II K]

Chemists Describe Solar Energy Progress And Challenges, Including The 'Artificial Leaf'


Nov. 6, 2009

http://www.sciencedaily.com/releases...1105132454.htm

Scientists are making progress toward development of an "artificial leaf" that mimics a real leaf's chemical magic with photosynthesis -- but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks. That is among the conclusions in a newly-available report from top authorities on solar energy who met at the 1st Annual Chemical Sciences and Society Symposium. The gathering launched a new effort to initiate international cooperation and innovative thinking on the global energy challenge.

[M II A II R II K]

Hot Electrons Could Double Solar Power


December 18, 2009

By Kevin Bullis

Read More: http://www.technologyreview.com/energy/24240/?a=f

For decades researchers have investigated a theoretical means to double the power output of solar cells--by making use of so-called "hot electrons." Now researchers at Boston College have provided new experimental evidence that the theory will work. They built solar cells that get a power boost from high-energy photons. This boost, the researchers say, is the result of extracting hot electrons.

- The results are a step toward solar cells that break conventional efficiency limits. Because of the way ordinary solar cells work, they can, in theory, convert at most about 35 percent of the energy in sunlight into electricity, wasting the rest as heat. Making use of hot electrons could result in efficiencies as high as 67 percent, says Matthew Beard, a senior scientist at the National Renewable Energy Laboratory in Golden, CO, who was not involved in the current work. Doubling the efficiency of solar cells could cut the cost of solar power in half.

[nomarandlee]

http://news.yahoo.com/s/afp/20091223...climatewarming

Taiwan unveils Asia's biggest solar plant: govt

Wed Dec 23, 3:20 am ET
TAIPEI (AFP) – Taiwan has unveiled what it calls Asia's biggest solar power plant as the island, which imports almost all its energy, seeks to tap into clean renewable resources, the government said Wednesday.

The two-hectare (4.9-acre) plant in south Taiwan's Kaohsiung county, an area that enjoys year-round sunshine, is equipped with 141 huge solar panels that can generate one megawatt in total, said the Atomic Energy Council.

One megawatt is enough to power 1,000 homes, according to an official at the council, which is also in charge of sustainable energy.

The facility, which started operating Tuesday, will help Taiwan cut its carbon emissions by up to 660-700 tonnes annually, officials said.

Taiwan estimates its solar energy industry will be worth up to 200 billion Taiwan dollars (6.25 billion US dollars) by 2020, said the council.

Taiwan's parliament in June passed a major renewable energy bill aimed at adding between 6,500 and 10,000 megawatts of installed energy from renewable sources over the next 20 years.

Currently, Taiwan produces only 2,278 megawatts, or 5.8 percent of installed capacity, from renewable sources, according to the state-run Taiwan Power Co.

..

[M II A II R II K]

Generating Solar Power After Dark


December 26, 2009

By TODD WOODY

Read More: http://greeninc.blogs.nytimes.com/20...-for-playback/

Solar farms that would serve two Western utilities are planning to use technology that will generate electricity after the sun goes down, a move that could be a potential game-changer for the industry.

The two farms being planned by SolarReserve of Santa Monica, Calif., would store the sun’s energy in molten salt, releasing the heat at night when it could be used to drive a turbine and generate electricity. Two utilities, NV Energy in Nevada and Pacific Gas and Electric, Northern California’s biggest utility, would buy the power.

[M II A II R II K]

Hybrid Solar Panels Combine Photovoltaics with Thermoelectricity


December 30, 2009

By Larry Greenemeier

Read More: http://www.scientificamerican.com/ar...d-solar-panels

Tar and shingles are hardly environmentally friendly materials, so the U.S. Department of Energy (DOE) hopes to soon help homeowners and businesses replace the roofs over their heads with something greener. To that end, the DOE awarded Weidlinger Associates, a New York City-based structural engineering firm, a $150,000 grant earlier this month (matched by a 10-percent commitment from the state) to develop durable hybrid solar roofing panels with integrated photovoltaic cells and thermoelectric materials that harvest the sun's energy to produce both electricity and hot water for buildings.

Weidlinger is working with Columbia University in New York City on the project, which the engineers and researchers hope will convert at least 12 percent of collected sunlight into electricity. This would be an improvement over the 5- to 10-percent conversion rate possible with relatively inexpensive thin-film plastic solar cells, although a far cry from the most complex (and expensive) solar cells, which have achieved a conversion rate as high as 41.6 percent.

--------------------------------------------------

Are Engines the Future of Solar Power?

[M II A II R II K]

Microscopic Solar Cells Could See More Sunlight


January 05, 2010

By Katherine Bourzac

Read More: http://www.technologyreview.com/energy/24295/?a=f

Researchers at Sandia National Laboratories have shrunk silicon solar cells down to the micro scale, opening new possibilities for improved efficiency. Multi-crystalline silicon, currently the gold standard for solar-cell efficiency, is expensive and produces cells that are heavy and brittle. Sandia's microscopic silicon solar cells use 100 times less material while operating with the same efficiency.

- In addition to lower materials costs, the smaller scale of these cells means they could be incorporated into compact optical systems for cheaper light-tracking and concentration. Researchers might even suspend them in inks that could be printed onto plastic to make efficient, flexible silicon-solar modules.

[M II A II R II K]

Solar Industry Says End Fossil Fuel Subsidies And Expect A Solar Boom


12.29.09

by Daniel Kessler

Read More: http://www.treehugger.com/files/2009...en-percent.php

A report by the Solar Energy Industries Association (SEIA) found that power from the sun could generate 15 percent of America's power in the next decade, but only if Washington levels the playing field on subsidies. The fossil fuel industry, led by oil and coal, received $72 billion in total federal subsidies from 2002 to 2008, but earlier this year President Obama called for those subsidies to end.

- Additionally, the amount of solar energy could jump from today's 1,500 MW to 350,000 MW by 2020. A new grid would be needed to distribute the additional energy, and a global deal among the G20 countries to phase out dirty energy subsidies would have to actually happen.

[M II A II R II K]

• Video Link

[M II A II R II K]

Solar cells made through oil-and-water 'self-assembly'


12 January 2010

Read More: http://news.bbc.co.uk/2/hi/science/nature/8452912.stm

Researchers have demonstrated a simple, cheap way to create self-assembling electronic devices using a property crucial to salad dressings.

- It uses the fact that oil- and water-based liquids do not mix, forming devices from components that align along the boundary between the two.

- In this approach, "blank" devices are etched with depressions to match precisely-shaped components. Simply dumped into a liquid, the components should settle down into the blank device like sand onto a riverbed, in just the right places.

[M II A II R II K]

2,400-Foot-Tall Solar Turbines To Power Arizona


01.07.2010

By Stuart Fox

Read More: http://www.popsci.com/technology/art...-power-arizona

Today's solar power plants work either through photovoltaics or heated steam. If Enviromission gets its way, tomorrow's plants will combine wind and solar, with acre-sized mirrors and multi-thousand-foot-tall chimneys generating turbine-spinning gusts. The technology's called solar updraft, and a $750 million, 200-megawatt project may just bring Enviromission's future into the present.

The plants work by generating pressure differentials between warm and cool air at the surface. Four acres of solar panels sit around a 2,400-foot-tall chimney, and above turbine-laden tunnels. The panels heat the air closer to the chimney far faster than the air at the ends of the tunnels. The warmer, less dense air then serves as a partial vacuum, drawing in the colder, denser air at the edges through the tunnels fast enough to spin the turbines and generate electricity.

[M II A II R II K]

Scientists Grow Cheap Biodegradable Solar Using Tobacco


by Jerry James Stone, San Francisco, CA on 01.29.10

Read More: http://www.treehugger.com/files/2010...th_tobacco.php

Researchers at UC Berkeley have hacked tobacco plants to grow synthetic photovoltaic cells which can then be extracted and sprayed onto any substrate to create solar cells.

How? The scientists tweaked a few genes within the tobacco mosaic virus to build tiny structures called chromophores. Once the plant is sprayed with the virus, the new chromophores will group into tightly coiled formations. Chromophores are structures that turn light into high powered electrons.

Each formation is hundreds of nanometers long and about three nanometers away from its neighbor. That spacing is very important. Just one atom closer would impede any electrical current. Harvesting the electrons would be nearly impossible.

"Over billions of years, evolution has established exactly the right distances between chromophore to allow them to collect and use light from the sun with unparalleled efficiency," said Matt Francis. "We are trying to mimic these finely tuned systems using the tobacco mosaic virus."

[M II A II R II K]

New twist on solar cell design


15 February 2010

Stuart Gary



Read More: http://www.abc.net.au/science/articl...15/2818151.htm

Scientists in the US have developed a new flexible and lightweight solar cell, which uses a fraction the amount of silicon used in conventional cells, while still achieving high light conversion rates.

Reporting in journal Nature Materials Professor Harry Atwater of the Caltech and colleagues believe their new design could be used in applications ranging from car sun roofs to devices in clothing.

The key is to the cells high efficiency is its use of small micrometre sized rods of silicon instead of traditional silicon wafers.

Incoming light bounces back and forth multiple times between the rods in the panel until it's absorbed.

Small alumina nano-particle reflectors are placed between the rods to ensure the light is guided as efficiently as possible.

The scientists claim up to 85% of usable sunlight is absorbed by the new panels, compared to approximately 17% efficiency with current commerically available solar cells.

Atwater says the silicon wire arrays offer a mechanically flexible alternative to conventional silicon wafer photovoltaics, and are much better at absorping in the near-infrared spectrum.

This allows overall sunlight absorption to exceed that of an equivalent volume of randomly textured silicon panels over a wide range of sunlight angles.

[M II A II R II K]

World’s biggest solar-powered boat unveiled


25 Feb 2010

Read More: http://www.grist.org/article/2010-02...boat-unveiled/

KIEL, Germany—A skipper hoping to become the first to sail round the world using solar power said his catamaran could carve a wake for pollution-free shipping as he unveiled the record-breaking yacht Thursday. “This is a unique feeling to see in front of me today a boat which I so often dreamed about,” said Raphael Domjan as the covers came off the $24 million boat, the world’s biggest solar-powered vessel.

PlanetSolar, a 100-by-50-foot white catamaran, has been designed to reach a top speed of around 15 knots, equivalent to 15 miles per hour, and can hold up to 50 passengers. It is topped by 5,380 square feet of black solar panels, with a bright white cockpit sticking up in the center.

Constructed at the Knierim Yacht Club in Kiel in northern Germany, its state-of-the-art design also means it will be able to slice smoothly through the waves even in choppy waters.

Domjan will launch PlanetSolar in late March before starring at Hamburg port’s 821st anniversary celebrations in May and undergoing testing between June and September. The world tour will then start in April 2011.

[M II A II R II K]

France builds world's biggest photovoltaic solar plant


March 2, 2010

Read More: http://www.physorg.com/news186770590.html

French energy giant EDF is building the world's biggest photovoltaic solar power plant at an abandoned NATO air base and plans to have it open by 2012, a spokesman said Tuesday.

Jean-Marc Dall'Aglio, of EDF's green energy subsidiary EDF-EN, said the 415 hectare (1,025 acre) site in Toul-Rosieres, near the eastern city of Metz, would produce 143 megawatts, enough for a town of 62,000 people.

The current largest photovoltaic plant is at Olmedilla in Spain, producing 60 megawatts. Several much larger plants are under construction in the United States and Australia and might beat the French contender.

Toul-Rosieres will quadruple nuclear-dependent France's photovoltaic power output, but still leave it far behind sunny Spain and Germany, which generate 1,671 MW and 1,505 MW respectively.

Dall'Aglio said it was difficult to find sites large enough for the huge arrays of solar panels needed to generate a viable amount of power, insisting that EDF was always looking for more.

Asked why the latest one was to be sited in cloudy Lorraine rather than the sunny south, he said that the state had decided to increase the tariff paid to solar energy producers in gloomy regions to encourage investment.

"We're hunting all the time, everywhere. In Toul-Rosieres the advantage is that the site is available straight away," he said, adding that EDF would pay the government rent of around a million euros (1.35 million dollars) a year.

Some 150 people will be involved in building the plant, including the work of removing asbestos from around 100 abandoned military structures, and once it is open it will employ 15 permanent staff, he added.

[leftopolis]

Fascinating thread--many new bookmarks for in depth perusal!

I actually have a solar question that I was hoping one of the other solar enthusiasts could point me to a website that could help me figure out the answer.

A little background:

The local school district has been covering all the high-school parking lots with a "roof" of solar panels--evidently they expect to get a substantial percentage of each school's power needs this way--with the added benefit of shading the cars from the hot summer sun.

On another thread, I read that the "Desertexpress" is expecting to start construction later this year. For those unfamiliar--it's a high-speed-rail that would go from Las Vegas to Victorville, CA and then on to Palmdale in order to essentially be fully connected with the new CA HSR in the works, connecting SoCal with NorCal--and thus, Las Vegas with all the big California cities.

It occurred to me that the 185 mile stretch through the desert, would benefit from just that type of solar panel "roof"--throughout the full length:
--It would provide power, something HSR needs alot of.
--It would provide shade for the tracks. It's my understanding they can warp/buckle in extreme temps, and that area can hit 120F in the summer!
--It would also provide shade for the train, which should at least slightly reduce air-conditioning needs on it, thus saving some power.
--I don't see a drawback, in the sense that the space is already being used for tracks, so why not use the space above the tracks and train in order to make it more efficient energy-wise and safer?

Finally, to my question:
I've determined that 185 miles x 10ft(random, easy figure to use), works out to 224 acres of solar panels! What I'm trying to figure out is, how much power would that produce potentially(given that the sun shines almost everyday of the year)?

If anybody can guide me to a site that will help me figure it out, I'd appreciate it. BTW, a metric site is OK, too--I can do math. Ultimately, I want to come up with a figure for the power produced and compare it to the expected power needs of the train itself. I'll be happy to report my findings here, if there's interest.

Thanks in advance.