Tag Archives: Solar Cell

Best Conditions for Generating Solar Energy

Solar panels use PV (photovoltaic) cells that convert sunlight into electricity. Assessing whether your property’s roof is in a good position to generate solar power is essential before committing to installing any solar energy technology.

Roof position

Your roof will need to face south or within 90 degrees of south and should be in a relatively sunny position. If your roof is overshadowed for part of the day then this will generate less power. As well as this your roof needs to be structurally sound and in a fit enough state to be able to support the weight of the panels.
The Energy Saving Trust advises that your roof should be at a pitched angle of between 30 and 50 degrees from the horizontal for best performance. If you have a flat roof, panels can be attached to a frame tilted at the optimum angle.

Housing Energy Advisor suggests that you use free online solar angle calculator to calculate the best angle for each month of the year and then work out an average. Alternatively, you could make the most of the summer sunshine by calculating the optimum angle for June and setting your panels in that position. This would be the best option if you want to produce as much energy as possible to sell back to the national grid. A third option would be to set your panels at the optimum angle for the winter months. In this scenario, it would be likely that you would still be able to produce enough energy for the summer months, but this will give the additional benefit of reducing the amount of energy you need to buy in the winter. Unfortunately this would also reduce the amount of surplus energy you’ll be able to sell.

Weather conditions

Solar energy systems will produce energy all year round, but will produce significantly less during the winter months. Solar panels can still generate energy even on a cloudy day and the Energy Saving Trust even estimates that a system can still generate up to a 1/3 of the energy on a cloudy day that would usually be produced on a sunny day.

Regular amounts of rainfall are essential to the efficient operation of solar panels, as this cleans off any dust and dirt that could settle on them and could prevent the sun’s rays from being efficiently harnessed. This also helps to keep the panels cool, which benefits the panels as they operate with greater efficiency at lower temperatures.

Guest Article by Amy Catlow.

Teenie Micro Solar Cell From Semprius

Pin Sized Solar Cell from Semprius

Picture courtesy Inhabitat website

 

Semprius just unveiled an teenie solar cell that is half the size of a pinhead, which when combined with powerful inexpensive lenses can concentrate sunlight more than 11,000 times and convert it to electricity!

Semprius has been a leader in Concentrated solar research and development. In 2008 they had come out with a method to slice monocrystalline solar wafers thin enough to be flexible and partially transparent but still maintain their high solar efficiency. The slender silicon slices are then imprinted onto a substrate using Semprius’s patented microtransfer printing process.

Semprius’ patented micro-transfer printing technology brings for the first time, high performance semiconductors to virtually any surface, including glass, plastic or metal substrates or even other semiconductor wafers. By liberating the semiconductor devices from their traditional substrates, Semprius technology enables the construction of a wide variety of new products with large-area, thin, and lightweight form factors, high reliability and low cost. The resulting circuit devices have levels of performance comparable to the original semiconductor.

 

Smaller and more efficient! Wonderful news for Solar and alternative energy market; if only it were affordable sooner.

Read the entire article here

Stanford’s Thinner Than The Wavelength of Sound Solar Cells

One thing we know about solar cells is that thinner it is less expensive it gets; thin film solar is cheaper than the standard silicon cells. Stanford University’s team of Researchers has come up with Solar cells thinner than the wavelengths of light which are also more efficient! They say Ultra-thin solar cells can absorb sunlight more efficiently than the thicker, more expensive-to-make silicon cells used today, because light behaves differently at scales around a nanometer (a billionth of a meter).

The team consists of Shanhui Fan, associate professor of Electrical engineering and postdoctoral researcher Zongfu Yu who is the lead on the PNAS paper. Aaswath Raman, a graduate student in applied physics, also worked on the research and is a coauthor of the paper.

Everyone worked with the assumption that light travels in a straight line i.e. if a ray of light hits a mirror it bounces back as another ray. When Yu began investigating the behavior of light inside a material of deep subwavelength-scale – substantially smaller than the wavelength of the light – that it became evident to him that light could be confined for a longer time, increasing energy absorption beyond the conventional limit at the macroscale. On further research Yu figured out that he could increase absorption rate by 12% by sandwiching the organic thin film between two layers of material – called “cladding” layers – that acted as confining layers once the light passed through the upper one into the thin film. Atop the upper cladding layer, he placed a patterned rough-surfaced layer designed to send the incoming light off in different directions as it entered the thin film.

The project was supported by funding from the King Abdullah University of Science and Technology, which supports the Center for Advanced Molecular Photovoltaics at Stanford, and by the U.S. Department of Energy.

Source – The Stanford News

Ivanpah Solar Project In California

There are many new Alternative energy projects coming up all over the US, and the US still has a lot of catching up to do when it comes to alternative energy when compared to the developing economies China and India. China is the leader in investment in alternative energy programs world over.

Under the EERE’s solar Energy technologies program many new alternative energy programs are developing. On August 12th the California Public Utilities Commission (CPUC) approved a power purchase agreement for the utility-scale Ivanpah Solar Electric Generating System. CPUC granted a 20-year contract between Southern California Edison Company and Ivanpah operator BrightSource Energy, Inc. for 117 megawatts (MW) of planned production from the three-tower, concentrating solar power (CSP) complex in the Mojave Desert of southeastern California. The contract calls for electricity to begin flowing on September 30, 2013. The site’s three plants will feature the company’s proprietary solar power tower technology, which employs thousands of flat mirrors to concentrate the sunlight on a central tower-mounted receiver. Water pumped to the receiver is boiled into steam, which drives a turbine to produce electricity. Solar power towers allow the capture of a greater percentage of solar energy than do other solar thermal technologies. Ultimately, the project is designed to generate approximately 400 MW of electricity, an output that would nearly double the existing generation capacity of CSP facilities in the United States.

The project will be sited on about 4,000 acres of public land proposed public land in San Bernardino County.

Project Overview
  • An approximately 400 megawatt solar complex using mirrors to focus the power of the sun on solar receivers atop power towers.
  • The complex is comprised of three separate plants to be built in phases between 2010 and 2013, and will use BrightSource Energy’s Luz Power Tower (LPT) technology.
  • The electricity generated by all three plants is enough to serve more than 140,000 homes in California during the peak hours of the day.
  • Located approximately 4.5 miles southwest of Primm, Nevada, in the desert on federal land managed by the Bureau of Land Management.
  • When constructed, Ivanpah will be the first large-scale solar thermal project built in California in nearly two decades and the largest in the world.
  • The Ivanpah Solar Electric Generating System will nearly double the amount of commercial solar thermal electricity produced in the US today.
Environmental Benefits
  • Avoids 400,000 tons of CO2 emissions per year; the equivalent of removing 70,000 cars off the road annually.
  • Employs a closed-loop dry-cooling technology, which reduces water use by 90 percent. Will use 100 acre feet per year, the equivalent of 300 homes’ annual water usage; and nearly 25 times less water than competing technologies.
  • Cuts major air pollutants by 85% compared to new natural gas-fired power plants.
  • Technology places individual mirrors onto metal poles that are driven into the ground, reducing the need for extensive land grading and using far fewer concrete pads than other technologies.
Economic Benefits
  • Construction Jobs                                 : 1,000 jobs at peak of construction; average 650 jobs annually over 3 year period
  • Operations and Maintenance Jobs : 86
  • State and Local Tax Benefits             : $400 million*
  • Total construction wages                   : $250 million
  • Total Employee Earnings                   : $650 million
    *Based on 30 year plant life cycle

Read the entire article here

Check out Brightsource Energy website

Solar Energy Now a Viable Large Scale Energy Source?

When I read “Solar Power is Cheaper than Nuclear Power” I seriously thought someone was trying to pull a quick one by talking about 20 years into the future as if it was happening in the present. Then I read the article on The Green Energy Collective Website in detail and was thrilled by the realization that 2 researchers at Duke University have come to the conclusion that Solar Energy may have reached grid parity!

It’s no secret that the cost of photovoltaic cells (PV) have been dropping for years. A PV system today costs just 50 percent of what it did in 1998. Breakthroughs in technology and manufacturing combined with an increase in demand and production have caused the price of solar power to decline steadily. Nuclear Power plants are being pushed as the only viable alternative economically right now. But now the Duke researchers are saying that Solar power has attained price parity in regards to Nuclear power.

The Study authors John Blackburn and Sam Cunningham say “Electricity from new solar installations is now cheaper than electricity from proposed new nuclear plants.” They have their study based in North Carolina.

According to Osha Davidson of Energy Collective, if the data analysis is correct, the pricing would represent the “Historic Crossover” claimed in the study’s title.

Two factors not stressed in the study bolster the case for solar even more:

1) North Carolina is not a “sun-rich” state. The savings are likely to be even greater for states with more sunshine –Arizona, southern California, Colorado, New Mexico, west Texas, Nevada and Utah.

2) The data include only PV-generated electricity, without factoring in what is likely the most encouraging development in solar technology: concentrating solar power (CSP).

Power costs are generally measured in cents per kilowatt hour – the cost of the electricity needed to illuminate a 1,000 watt light bulb (for example) for one hour. When the cost of a kilowatt hour (kWh) of solar power fell to 16 cents earlier this year, it “crossed over” the trend-line associated with nuclear power.

Courtesy Wikimedia Commons

Currently US energy supply depends 70% on Fossil Fuels (including Coal) and 20% on Nuclear Energy. The researchers say that mass produced Solar energy is being offered to customers at 14cents per kilo Watt Hour, which would make Solar energy one of the least expensive energy sources in America.

As I looked it up for more details I came across articles in NYTimes and a discussion on Slashdot both make some very interesting reading.

If what the researchers say hold true, we should have greener energy powering our day to day activities within a decades time. Sounds good will have to wait and see how it pans out. Live Green!

Some interesting facts:

  • From 1943 to 1999 the U.S. government paid nearly $151 billion, in 1999 dollars, in subsidies for wind, solar and nuclear power, Marshall Goldberg of the Renewable Energy Policy Project, a research organization in Washington, wrote in a July 2000 report. Of this total, 96.3 percent went to nuclear power, the report said.
  • According to credit rating agency Moody’s Nuclear installations invariably lower the credit rating of the company. “Of the 19 applications at the N.R.C.(US Nuclear Regulatory Commission) , 90 percent have had some type of delay or cancellation, run into a design problem, suffered cost increases and/or had the utility bond rating downgraded by Wall Street.”
  • Nuclear subsidies in the Senate proposal include five-year accelerated depreciation; tax credits for investments and production and eligibility for the advanced energy tax credit; an increase in government insurance against regulatory delays; access to private activity bonds; and a $36 billion increase in loan guarantees, bringing the total to $56 billion. (The Nuclear Energy Institutes Goal was a $100 Billion!)

Source of the article here

Another article here

Duke University Website

The Study Published by the researchers in full can be read here

The American Solar Challenge 2010 Solar Chariot Races

The American Solar Challenge is a road race for Solar powered cars which is held every alternate year in the US. The aim of the competition is to design, build, and drive solar-powered cars in a cross-country time/distance rally event. Teams compete in a 1100 mile drive from Broken Arrow, OK to Naperville, IL. The route has been chosen to combine pieces of old routes used in previous events, giving a bit of an historical tribute for the 20 years of organized events in North America.

This year the winner out of 17 teams that qualified for the final road race were from the University of Michigan. The Road race started on the 16th of June 2010 at Broken Arrow Oklahoma and ended on the 26th of June in Naperville Illinois.  The following is the route :

  • Sat, June 19: Travel day / Support Vehicle Inspections in Broken Arrow, OK
  • Sun, June 20: Start in Broken Arrow, OK; must reach Neosho, MO checkpoint
  • Mon, June 21: Finish in Topeka, KS
  • Tue, June 22: Start in Topeka, KS; must reach Jefferson City, MO checkpoint
  • Wed, June 23: Finish in Rolla, MO
  • Thu, June 24: Start in Rolla, MO; must reach Alton, IL checkpoint
  • Fri, June 25: Finish in Normal, IL
  • Sat, June 26: Start in Normal, IL; finish in Naperville, IL

The Race finalists are chosen from a preliminary round which takes place in the Formula Sun Grand Prix (FSGP) Track race in Cresson Texas. The top teams in FSGP, which complete at least 100 laps in a single day, or any two consecutive day total of 150 laps, will automatically qualify for ASC.  Only Official Laps will count towards qualifying mileage.  The track is 1.7 miles.

The 17 finalists can be found HERE Most of the participants were from the US while there were also teams from Canada, Germany and Taiwan.

The top 3 finishers were :

  1. University of Michigan
  2. University of Minnesota
  3. Hochschule Bochum from Germany

For The University of Michigan Solar team this is their sixth impressive win in the ASC race. Their solar car which is called Infinium has topped 105 miles per hour speed during test runs. The Michigan team finished the 1200 mile race in 28 hours, 14 minutes, and 44 seconds. The above 3 are also links to the respective cars which are simply amazing and following are pictures the teams vehicles in the winning order.

It is impressive to see renewable technology being developed by the younger generation every day aimed towards a greener tomorrow. Gives all of us hope that a day where our dependence of fossil fuel ends may indeed be possible. Live Green!

Read More about it on the ASC 2010 Website

Solar Impulse: The “Utopian” Flight of Fancy Realized!

According to the American Poet and Novelist James Dickey “Flight is the only truly new sensation than men have achieved in modern history” and I tend to agree.

Flight in itself helped humankind shorten the distances across the oceans and gave wings to mans imagination, it also helped man reach the moon and beyond. Like Bill Gates said The Wright Brothers created the single greatest cultural force since the invention of writing.  The airplane became the first World Wide Web, bringing people, languages, ideas, and values together”. It has been 100 plus years since the first flight by the Wright brothers and the planes have gone from biplane gliders to supersonic jets and beyond. Until now the faster plane did not mean it was focusing on fuel efficiency, mostly longer flights meant larger engines and higher fuel capacity. In today’s move towards a greener energy solution and a lower carbon footprint it looked as though the flights were one of the things which we would be still running on oil however pricey it got.

I called it a flight of fancy not to trivialize it, but to say how unbelievably awestruck I am! The 20th century has had its share of amazing discoveries from the first flight to the moon landing, conquering the Everest and the Poles, circum navigating the earth faster than the previously estimated etc… It was also the century when humankind adversely effected the environment most and created the need for alternative energy sources a priority for the survival and sustenance of our planet.

On the 7th of June 2010 something spectacular happened, which helped take the journey in the skies to the next level- A flight powered purely by the Sun- Solar Impulse!!

The Brains behind the Solar Impulse Piccard and Borschberg Pictures from Solar Impulse

The team led by two pilots- innovators & visionaries: Bertrand Piccard, psychiatrist and aeronaut, who made the first non-stop round-the-world balloon flight, is the initiator and chairman AND André Borschberg, an engineer and graduate in management science, a fighter pilot and a professional airplane and helicopter pilot, as the CEO started their journey towards creating The Solar Impulse in 2003 and announced it in the May of 2007. The former’s avant-garde vision and the latter’s entrepreneurial and managerial experience are an ideal combination. The idea at the heart of the Solar Impulse project is to get closer to perpetual flight in a machine powered only by solar energy. This challenge necessitated the use of technology unique to this type of aircraft, such as that linked with the gathering of energy via photovoltaic cells and storing it in batteries for use in powering the engines at night.

On the morning of 07/07/2010 at 6.51 AM in Switzerland André Borscherg CEO and co-founder of the Solar impulse project took to the skies in the Solar Impulse HB-SIA from the Payerne Airbase. The flight was powered by 12,000 solar panels built into its enormous 63.4meter wing, which charged its 400kg of batteries during the long ascent. The flight successfully completed its aim of 24 hours in the flight using nothing but solar power and landed back in the Payerne Airbase after 26 hours and 9 minutes having successfully completed its mission. The organizers said the flight was the longest and highest by a piloted solar-powered craft, reaching an altitude of just over 28,000 feet above sea level at an average speed of 23 knots, or about 26 miles per hour.

After the flight landed successfully André Borschberg said from the cockpit of the Solar Impulse “During the whole of the flight, I just sat there and watched the battery charge level rise and rise! Sitting in a plane producing more energy than it consumes is a fantastic feeling”.

Bertrand Piccard added “This is a highly symbolic moment: flying by night using solely solar power is a stunning manifestation of the potential that clean technologies offer today to reduce the dependency of our society on fossil fuels!”.

The Associated Press quoted Dr. Piccard as saying “When you took off, it was another era. You land in a new era where people understand that with renewable energy you can do impossible things.”

The project’s designers had set out to prove that — theoretically at least — the plane, with its airliner-size, 208-foot wingspan, could stay aloft indefinitely, recharging batteries during the day and using the stored power overnight. “We are on the verge of the perpetual flight,” Dr. Piccard said.

“The airplane is the means of transport using the most energy and it alone represents more than 3 % of the total gas emissions contributing to the greenhouse effect on the planet! As an aerial photographer I know something about this. If all airplanes were to become solar, this would be tremendous. And Piccard is a dreamer: I know of nothing more extraordinary than helping people realise their dreams.”-Yann-Arthus Bertrand

There might or might not come a time when a 300 passenger plane flies on solar power alone. In the mean while even as a single person flight it gives us hope that a greener option is possible. And like the Solar impulse website says “if we do not invest in the scientific means to develop new energy sources, we shall find ourselves in a major crisis, which will prevent us from handing over the planet to the next generation.”


You can read more about the Solar Impulse on its website HERE

Pictures source Solar Impulse.com

Find the Article on Solar Impulse flight in the NY times here

A Solar Panel That Catches Full Solar Spectrum

Source of Picture www.inhabitat.org

Solar panels in the market now only have an efficiency of up to 15% at the maximum, most are between10-12% normally. That means only 10-12% of the sun light is being utilized now. Scientists have been working hard to find a way to increase the efficiency by shaping the panels differently, using mirrors etc… Now RoseStreet Labs has managed to increase the efficiency 3 fold! They have created a solar cell which uses 3 different layers of Photo Voltaic cells in a single layer thin-film solar panel to capture different spectrum’s of the Sun’s radiation.

RoseStreet Labs Energy Inc.(RSLE) had this to say in a press release dated Sept 29th 2009 “RoseStreet Labs Energy, Inc. (RSLE) announced today a breakthrough demonstration of the first known Nitride/silicon tandem solar cell. Utilizing the same Nitride material technology as solid state lighting and blue lasers, RSLE fabricated and tested a working photovoltaic cell that couples a silicon solar cell with a Nitride Thin Film. This is a major milestone in RSLE’s product roadmap to achieve substantially higher solar efficiencies than standard silicon or other thin film solar cells.”

They used their IBand technology to achieve this new development and are the first to do so. The idea of integrating three bands — each band capturing a different part of the spectrum — has been around for a while but this is the first proven success. RSLE’s demonstration device was fabricated on high volume CVD technology, validating the potential for high volume commercialization. The company says this technology illustrates great promise for high efficiency thin film solar efficiencies above 35% by potentially capturing the full spectrum of the sun’s spectrum.

Read the first Press Release by RoseStreet Labs Here

Read Related articles about it at Renewable Energy World or  Inhabitat


An Interesting read about Thin Film Solar:

Thin Film Solar Cells: Fabrication, Characterization and Applications

Solar Cell On Paper

Picture source CNET

Read an interesting post on CNET about MIT researchers printing a solar cell on paper! like all new developments it is still in its emryonic stage, not yet viable for mass production. The article by Martin LaMonica covers the MIT lab and it’s work on the latest technology indepth.

MIT is focusing much of its effort on quantum dots, or tiny crystals that are only a few nanometers in size. A human hair is about 50,000 to 100,000 nanometers thick. Using different materials and sizes, researchers can fine-tune the colors of light that quantum dots can absorb, a way of isolating good candidates for quantum dot solar cells.

These kind of developments are a positive step in the right direction. Martin says that if .3% of the US is covered by solar panels with 10% efficiency it can prodcue 3times the energy needed for the US consumption! May be in future we will be using staple guns to attach solar cells!

Vladimir Bulovic Director of the Eni-MIT Solar Frontiers research center says for any new discovery to be viable or fully developed takes up to 10 years!  

You can read the full article here

Affordable Solar Power Using Purple Pokeberries

Purple Pokeberries

Image Courtesy Muffet

New Studies have found that Purple Pokeberries Hold Secret to Affordable Solar Power Worldwide.

Nanotech Center scientists have used the red dye made from pokeberries to coat their efficient and inexpensive fiber-based solar cells. The dye acts as an absorber, helping the cell’s tiny fibers trap more sunlight to convert into power.

Pokeberries proliferate even during drought and in rocky, infertile soil. That means residents of rural Africa, for instance, could raise the plants for pennies. Then they could make the dye absorber for the extremely efficient fiber cells and provide energy where power lines don’t run, said David Carroll, Ph.D., the center’s director.

To make the cells, the plastic fibers are stamped onto plastic sheets, with the same technology used to attach the tops of soft-drink cans. The absorber — either a polymer or a less-expensive dye — is sprayed on. The plastic makes the cells lightweight and flexible, so a manufacturer could roll them up and ship them cheaply to developing countries — to power a medical clinic, for instance.

Read More from ScienceDaily