1、 electronics for you July 2010 157w w w. e f y m a g. c o ma lower-cosT soluTionWith the race on to have the most efficient, low-cost solar module on the market, GE is focusing its R&D efforts on thin-film photovoltaic (PV technology in conjunction with PrimeStar Solar, which is headquartered in

2、 Arvada, Colorado, USA.Mano Manoharan (Mano, general manager, GE Global Research, based out of GEs largest multidisciplinary center in the world at GE John F. Welch Technology Center, Bengaluru, has immense technical expertise and experience in the areas of nanotechnology, fracture mechanics, surfac

3、eengineering and mechanical properties of materials. He speaks to Uma Bansal, deputy editor at EFY, about the trends in solar cells and the reason for choosing cadmium-telluride (CdTe technology for their modulesQ Qof late, what have been the major advances in solar celltechnology?Current advancemen

4、ts are in the areas of overall ef-ficiency improvements of thin-film modules and bringing their costs down. Advancements are also being made in the direction of maintaining high reliability and expected lifetime of 20 years.what areas of thin-film solarcells are being researched worldwide and at Ge?

5、We have a global team of allour four of GE Global Research centres working on thin-film solar. In addition, GE scientists are working closely with our partners at PrimeStar to develop our thin-film technology.We are looking at several key areas in order to achieve a best-in-class product, including

6、device efficiency, reliability, production and installation costs, and manufacturability.Hundreds of technologists in Germany, China, India and the United States are working on GE solar technologies today, addressing these challenges.The team in Munich is utilising world-class indoor and outdoor sol

7、ar module system test facilities where they study finished module performance to identify and address degradation mechanisms and packaging issues. In addition, this team also brings deep expertise at the system level. This allows them to define system-leveloptimised features and metrics for the modu

8、le.In China, where most of the worlds CdTe raw materialsare found, researchers at GEs China Technology Center in Shanghai are focused on CdTe materials and the impact they have on device performance. Improving materialquality and developing advanced materials characterisa-tion techniques are key top

9、ics being addressed by the Shanghai team.In India, GE is leveraging extensive modeling capabili-ties at its GE John F. Welch Technology Center in Bengaluru. Unlike the exclusively experimental approach favoured by many in this field, GE believes that dramatic improvements mano manoharanGeneral manaG

10、er, Ge Global research, benGaluruThe market-leading thin-film modules today are slightly over 11 per cent efficient with costs of around 84 cents/watt. 158 July 2010 electronics for youw w w. e f y m a g. c o mQ Q Q QQQQQin thin films are impacted by the same price and supply volatility as has been

11、seen with silicon. In addition, silicon-based solar modules generally have higher manufacturing costs than thin-film products.Do you think that thin-film solar cells will make solar power a truly viable alternative?The key to making solar power more viable is reducing the cost of producing electrici

12、ty from the solar-based tech-nology. The closer the solar gets to grid parity, or on par with fossil fuels like coal, the more the viability.We believe thin-film solar represents one of the most promising ways to achieve these cost goals. These will cost less to produce and install versus silicon-ba

13、sed cells. And while their efficiency levels are not as high as that of silicon today, we think that the further improvements we make in efficiency, balanced against cost, will represent the most at-tractive option for customers.in comparison to other thin-film solar technologies, what impact does c

14、dTe have on the device performance?Of all the thin-film materials, PrimeStars CdTe solar technology matched up best with GEs R&D capabilities. Were already seeing promising results in the labs. Enhanc-ing our materials understanding and the device design will be key to delivering a product that

15、is truly best-in-class. Andwith CdTe, there is more headroom for device efficiency than with other thin-film PV modules.cd is a toxic material, so the solar panels based on cdTe will not be rohs-compliant. Going by that, how success-ful will these be?GE and others like the US Department of Energy (D

16、oEhave studied this aspect. The US DoE has found that useof CdTe PV modules does not present any risk to health or environment, and recycling the modules at the end of theirlife addresses environmental concerns, if any.Cadmium used in the GE/PrimeStar module is a stable compound when bonded with tel

17、luride. In addition, the module is encapsulated between two layers of glass. Theamount of cadmium in a thin-film solar panel is less than ina typical battery.During their operation, CdTe modules do not produceany pollutant and, furthermore, by displacing fossil fuels, these offer great environmental

18、 benefits. GE has a compre-hensive recycling plan, and will work with customers to reclaim the product after the life-cycle is complete. what are your long-term goals in terms of cost and efficiency? When we go to the market in early 2011, we want to bethe industry leader. We see GEs investment in t

19、hin film as an opportunity to offer the most cost-competitive solar solu-tions to our customers.in the device performance and reliability will be realised through a deeper understanding of the materials and basic physics of the device. The team in Bengaluru is tasked with building comprehensive mode

20、ls to help guide advanced device design.Finally, GEs research team in Niskayuna, NY, is working on all facets of CdTe module development, in-cluding material growth, device development and robust process development. Their technical expertise cuts across diverse fields such as surface chemistry, las

21、er process -ing and plasma physics. Equally diverse is their product development experience, which they have derived from GEs other technology-focused businesses such as health-care, lighting and batteries.In the future, the key areas where you will see im -provements are efficiency and cost. These

22、are the main factors influencing the future viability of the clean energy source.what exactly is the nature of Ges relationship with Primestar? have you licenced their cdTe thin-film tech-nology, or is there some other sort of a relationship?GE is a majority stakeholder of PrimeStar Solar, an emergi

23、ng solar thin-film technology and manufacturing company. what factors determine the efficiency of a solar panel?The major factors include the amount of light that can pass through the window layers and reach the absorb -ing materials, the effectiveness of the absorber material to transform the incoming photons into carriers, and the ability to extract the carriers from the module with low losses.