New Energy’s see-thru SolarWindow cells surpass thin-film and solar in artificial light

BURTONSVILLE, USA: New Energy Technologies Inc., a next-generation alternative and renewable energy developer, announced that new tests of the company’s ultra-small solar cells for use in its transparent SolarWindow have demonstrated substantially superior performance over current thin-film and solar photovoltaic technologies at generating electricity from artificial light -– an important advantage over conventional solar technologies which are limited by their capacity to function well where exposure to direct sunlight is available.

“One of the biggest issues with today’s solar products is their dependency on direct sunlight, which our cells have demonstrated the potential capacity to overcome,” explained Meetesh V. Patel, Esq., President and CEO of New Energy Technologies.

“We’re now actively working to coat these cells onto transparent glass in order to fabricate our SolarWindows, which generate electricity and have the potential to be installed virtually anywhere that either direct sunlight or artificial lighting such as fluorescent systems emit visible light. In contrast, today’s building-integrated solar and photovoltaic products are limited to installation on south-facing surfaces, as is the case with currently-available solar materials tested in these newest experiments.”

In a series of new experiments, researchers repeatedly tested New Energy’s ultra-small solar cells on a 1”x1” substrate against today’s popular solar materials for their capacity to produce electricity under varying artificial light conditions, mimicking the levels of light exposure in homes and commercial offices.

In every case, New Energy’s solar cells, the smallest reported organic solar cells of their kind in the world, exponentially outperformed all of the conventional materials tested.

Under normal office lighting conditions, without the benefit of outside natural light from windows, New Energy’s ultra-small solar cells produced:

* Almost two-fold greater output power density than monocrystalline silicon, an established commercial solar cell material;
* More than eight-fold greater output power density than copper-indium-selenide, known for its high optical absorption coefficients and versatile optical and electrical characteristics; and
* More than 10-fold greater output power density than flexible thin-film amorphous-silicon, a popular ‘second-generation’ solar thin-film material.

New Energy's solar cells generate electricity not only from the visible radiation found in sunlight but also by using the visible light found in artificial illumination, such as the fluorescent lighting typically installed in offices and commercial buildings. While the majority of today's solar cells can only be installed where direct sunlight is available, New Energy's cells could be installed close to any source of visible light.

New Energy’s SolarWindow technology makes use of an organic solar array, which has the same desirable electrical properties as silicon, yet has a considerably better capacity to ‘optically absorb’ photons from light to generate electricity and achieves transparency through the innovative use of conducting polymers. Each solar array is composed of a series of twenty ultra-small solar cells measuring less than ¼ the size of a grain of rice each.

The organic solar cells are fabricated using environmentally-friendly hydrogen-carbon based materials, and successfully produce electricity, as demonstrated in a peer-reviewed study in the Journal of Renewable and sustainable Energy of the American Institute of Physics.

Click here to view the study: http://dx.doi.org/10.1063/1.2998825

The superior optical absorption properties of New Energy’s ultra-small solar cells enables development of an ultra-thin film (only 1/1000th the thickness of a human hair, or 1/10th of a micrometer) that can be utilized to produce a transparent solar window. In photovoltaic applications such as see-thru windows, where transparency is a primary concern, today’s thin film solar cells simply cannot be utilized to produce a transparent solar window for application in homes, offices, and commercial buildings.

Malibu opens first green TFPV fab using Linde’s fluorine technology

MUNICH/OSTERWEDDINGEN, GERMANY: Delivering a major step forward in sustainable solar power, Malibu today launched the world’s first thin-film solar module factory that completely eliminates the use of nitrogen trifluoride (NF3), a greenhouse gas with a significant global warming potential, from the manufacturing process.

Working in close collaboration with researchers from technology provider Linde Gases, a division of The Linde Group, scientists at Malibu’s development centre in Bielefeld, Germany, have developed an improved cleaning process using on-site generated fluorine (F2) made with Linde’s patented technology.

As a result, the carbon payback time –- the time it takes the use of solar panels to offset the environmental impact of their manufacture –- is reduced by up to one year. This improved process will now be rolled out to their new 40MW production facility in Osterweddingen, Germany.

Dean O’Connor, Head of Market Development & Technology at Linde Gases Division, said: “Linde and Malibu have clearly demonstrated their leadership and foresight in helping the thin-film PV industry to reach a watershed moment. Green energy will only be truly green when the entire supply and manufacturing chain works together to minimise environmental impact.”

According to Konrad Kaiser, General Manager Malibu: “Not only does the F2 cleaning process eliminate a major source of potential greenhouse gas emissions for our thin-film solar panels, it also speeds our processing and uses less material. This improves the overall sustainability of our product by reducing both environmental impact and manufacturing costs.”

In 2008, Linde and Malibu established their Joint Development Programme for the development of advanced material technology to improve cell efficiency, throughput and yield. F2 cleaning is the first of a number of material-based processes to emerge from their successful collaboration. NF3 and other fluorine compounds, such as sulfur hexafluoride (SF6), are used to clean the process tools that make the important silicon photovoltaic layers in thin-film solar modules.

IEC certification for Applied's world’s largest solar panels

SANTA CLARA, USA: Applied Materials, Inc. announced that the 5.7m2 solar photovoltaic (PV) modules produced by its SunFab Thin Film Line, using both single and more advanced tandem junction technologies, were awarded International Electrotechnical Commission (IEC) certification, validating their exceptional performance under extended outdoor exposure.

Certification of these SunFab modules, which are the world’s largest available solar PV panels, unleashes an opportunity for the widespread incorporation of SunFab panels in utility-scale, thin film solar farms to further drive down the price of clean electricity.

“We expect 5.7m2 modules to become the standard for utility-scale PV power,” said Dr. Randhir Thakur, senior vice president and general manager of Applied Materials’ Display and SunFab Solar Business Group. “Applying SunFab technology to ultra-large modules creates an unprecedented opportunity to reduce both manufacturing and installation costs, transforming solar PV into a long-term solution to provide the world with affordable energy from a renewable source.”

Certification was awarded by TÜV InterCert, confirming that the SunFab modules meet IEC standards 61646 and 61730. “Applied’s 5.7m2 modules are four times bigger than anything we’ve ever tested,” said Sergizzarea, president and CEO of TÜV InterCert.

“We made modifications to the laboratory and added equipment to enable us to test modules this large. Creating a PV product of this size that can pass all of the IEC tests while maintaining mechanical and electrical integrity is an impressive feat of engineering.”

The quarter-sized 1.4m2 modules produced on the Applied SunFab Thin Film Line received IEC certification earlier this year. However, a full-size 5.7m2 panel designed to maintain high power output while subjected to years of exposure to sunlight, extreme temperatures, wind and precipitation was a new challenge.

Applied’s technology and engineering expertise in flat-panel display and architectural glass systems enabled it to deliver the critical uniform conversion properties required across large areas. An innovative, integrated bonded rail support structure strengthens the module, allowing it to withstand wind and seismic loads while enabling the reduction of installation costs by greatly simplifying the mounting structure.

Why solar/PV is good for India? An ISA perspective!

Recently, the India Semiconductor Association (ISA) held an educative briefing session on the potential of the solar PV market in India, which was conducted by Rajiv Jain, Director, Government Relations, ISA.

This meeting was held well before iSuppli issued a warning that there could be global solar sunburn in 2009! I am sincerely hoping that most of the points mentioned by ISA's Jain still hold good in the coming year, and that India really does well and takes off in solar photovoltaics.

The ISA's vision: To help make India an attractive global destination for PV manufacturing and a world leader in solar energy.

Starting with the basics of photovoltaics, he said that it is a package of solar cells used to convert energy from sun to electricity. In simpler words, photons from sunlight knock electrons into higher state of energy, thus creating electricity. The electricity can be used to power equipment or recharge a battery. A typical PV system mainly consists of a PV module, battery, inverter, controller and junction box.

Focusing on the technological landscape, he touched upon the two key technologies for solar: crystalline and thin film.

Crystalline silicon is said to be the most mature Si wafer technology, with the largest market share. Though, high on cost, it has a typical efficieny of 14-18 percent. Crystalline silicon is said to suitable for rooftop applications.

Thin film is nothing but thin layers of photosensitive materials on glass. It is currently on high growth due to silicon shortage, and very low on cost due to low material consumption. The efficiency is about 6.5-8 percent.

A third technology, nanotechnology, is the future technology for cost reduction. It is more in the R&D space as of now.

Present scenario for solar
So what's the present scenario? In 2007, of $71 billion invested in new renewable energy (RE) capacity globally, 30 percent was in solar PV. It is the fastest growing area in the energy sector, with a CAGR of 47 percent over the last five years.

Grid-connected solar PV has been high growth market segment in 2007 (50 percent increase). Also, 86 percent of the PV installations are largely in four countries, with Germany at 47 percent being the outright leader.

Market drivers are said to be attractive feed-in tariffs, national PV market development and acceptance, RE obligations through solar PV, access to cheaper mode of finance, manufacturing incentives as well as strong R&D.

Why solar for India
I have addressed this in an earlier blog post. Here's what Jain had to say, and it is mostly in line with the earlier discussions.

First, India has among the highest solar irradiance globally. It also has the best quality reserves of silica in Orissa and Andhra Pradesh. India has also established itself low cost producer and assembler of solar PV cells and modules.

The major challenges include attaining scale and integration for cost reduction, and, R&D for development of the industry.

Solar insolation in India
To start with, the daily average solar energy incident varies from 4-7kWh per m2. Next, we have multiple sites with solar irradiation >2000 hours per year. In contrast, Germany has 900-1,200 hours per year. Further, most parts of India have 300-300 sunny days in a year translating into a potential of 600GW. Also, potential in some states like Rajasthan is 35-40 MW per m2.

It is well known that the Indian semiconductor policy of 2007 has triggered off the now well publicized efforts in solar initiatives. The government of India has received 16 applications with investments envisaged at app Rs. 1,55,000 crores.

The investments in solar PV manufacturing exceed Rs 1,25,000 crores. Generation based incentives (GBI) are going to be key.

Potential market segments in India
There are quite a few, actually. In rural electrification, the government of India's target is to achieve 'Electricity for all by 2012'. About 18,000 remote villages will likely be electrified through RE. About ~25 percent of the remote villages, i.e., 4,500 villages, form a very viable market.

Next comes telecom back-up power! PV is a cost effective alternative to diesel generators (DG) for back up power for shorter duration, as DG based systems suffer from several disadvantages.

Another key market could be grid connected solar PV based generation. Current tariffs do not provide attractive IRR to developers. Decreasing system prices are however, likely to improve the economics.

Finally, roof based BIPV is said to be an alternative to reduce the cost of power procured by commercial buildings.

ISA's recommendations
The ISA has also made salient recommendations via its report on the industry. These include areas such as manufacturing: with an aim to encourage companies investing in 'Scale and integration', provision of capital subsidy to larger number of units, availability of funds at a cheaper rate, and an emphasis on R&D.

Also, the ISA has recommended that GBI be given for a tenure of 20 years, with the present period being 10 years. Further, it has suggested an accelerated depreciation along with the GBI scheme, and the availability of GBI for an unlimited capacity for a period of five years. The ISA has recommended an enactment of the RE Law requiring utilities to progressively increase power purchase from RE.

On its part, the ISA has been working with the government of India and various state governments as well. It has a sound rapport with concerned ministries - MNRE, DIT and NMCC.

The ISA has also assisted in the technical evaluation of solar PV proposals received in Fab City, Hyderabad. It has also drafted a semiconductor policy for the government of Karnataka, which should be out early next year, hopefully. The ISA is also working with several other state governments to promote the industry in their states.

The second ISA Solar PV Conclave is scheduled for November 2009 at Hyderabad.

Very good intentions, all of these! Now, for the Indian industry and the government to deliver, and walk hand in hand!!