Saturday, January 26, 2013

Thin Film Solar Cells: New World Record for Solar Cell Efficiency

Jan. 18, 2013 — In a remarkable feat, scientists at Empa, the Swiss Federal Laboratories for Materials Science and Technology, have developed thin film solar cells on flexible polymer foils with a new record efficiency of 20.4% for converting sunlight into electricity. The cells are based on CIGS semiconducting material (copper indium gallium (di)selenide) known for its potential to provide cost-effective solar electricity. The technology is currently awaiting scale-up for industrial applications.

To make solar electricity affordable on a large scale, scientists and engineers the world over have long been trying to develop a low-cost solar cell, which is both highly efficient and easy to manufacture with high throughput. Now a team at Empa's Laboratory for Thin Film and Photovoltaics, led by Ayodhya N. Tiwari, has made (yet another) leap ahead. They achieved a record 20.4% energy conversion efficiency for thin film CIGS solar cells on flexible polymer substrates, a massive improvement over the previous record of 18.7% achieved by the same team in May 2011. Tiwari’s team has been investigating and developing various thin film solar cell technologies for some time. Over the years the laboratory has boosted the photovoltaic conversion efficiency of flexible CIGS solar cells time and again, from 12.8% in 1999 – the group’s first world record – to 14.1% in 2005, 17.6% in 2010 and 18.7% in 2011.

Closing the efficiency gap to silicon wafer cells

The latest in the series of records has been achieved, thanks to innovative ideas and excellent team work in the lab, especially by PhD students Adrian Chirila and Fabian Pianezzi. The team has succeeded in modifying the properties of the CIGS layer, grown at low temperatures, which absorbs light and contributes to the photo-current in solar cells. The cell efficiency value was independently certified by the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany. What’s more, Empa’s new record efficiency for flexible solar cells now even exceeds the record value of 20.3% for CIGS solar cells on glass substrates – and equals the highest efficiencies for polycrystalline silicon wafer-based solar cells.

 "We have now – finally – managed to close the "efficiency gap" to solar cells based on polycrystalline silicon wafers or CIGS thin film cells on glass", says Tiwari.

Thin film, lightweight and flexible high-performance solar modules are attractive for numerous applications such as solar farms, roofs and facades of buildings, automobiles and portable electronics and can be produced using continuous roll-to-roll manufacturing processes that offer further cost reductions compared to standard silicon technologies. In other words, they have the potential to enable low-cost solar electricity in the near future. “The series of record efficiencies for flexible CIGS solar cells developed at Empa demonstrates that thin film solar cells can match the excellent performance of polycrystalline silicon cells. Now it is time for the next step, the scale-up of the technology to cover large areas in a cost-efficient roll-to-roll manufacturing process with an industrial partner”, says Gian-Luca Bona the Director of Empa. For this purpose, Empa is collaborating with Flisom, a start-up company involved in industrialization of flexible CIGS solar cells.

The research work has been supported over the years by the Swiss National Science Foundation (SNSF), the Commission for Technology and Innovation (CTI), the Swiss Federal Office of Energy (SFOE) and the EU Framework Programmes.

Obama opens door for renewable energy push in US

In his inaugural speech for his second term in office, U.S. President Barack Obama has upped the ante, promising to show global leadership on climate change and support the development of clean energy...

In his speech, Obama said he would double the production of alternative energy in the next three years. He added that his administration would focus on efficiency as a way to reduce energy demand, by modernising more than 75 percent of federal buildings and improving the energy efficiency of 2 million American homes.
It was the most Obama had said on climate change for some time, and it was a stronger affirmation of the science underlying climate change than Obama has offered on other occasions: "Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires and crippling drought and more powerful storms," Obama said.
On renewable energy, Obama spoke with an almost religous zeal: "The path towards sustainable energy sources will be long and sometimes difficult. But America cannot resist this transition; we must lead it. We cannot cede to other nations the technology that will power new jobs and new industries - we must claim its promise. That is how we will maintain our economic vitality and our national treasure - our forests and waterways; our croplands and snowcapped peaks".


Not surprisingly, the speech has been widely heralded by clean energy groups: The Sierra Club commended Obama “for his vision of an economic recovery plan that recognises the vital role of clean energy.”
The American Wind Energy Association and the Solar Energy Industries Association issued a joint statement saying the two organizations “applaud President-elect Obama’s aggressive goal of doubling the production of alternative energy in the next three years.”

Friday, January 11, 2013

Solar Power Plant 1 Mega Watt(MW) Installation in Chennai Details

  • Periasamykandasamy - 
    So, it is official now that the falling PV price is not due to any technology break through or due to higher scale of operation, as claimed by renewable energy 'experts". It is purely an economic jumble of taxes / incentives by China.

    Those who were claiming that the PV panel prices are "falling" and who were projecting the panel prices based on this "falling trend", please understand the engineering reality.

    Solar radiation is free but the intensity is so weak, that it takes lot of efforts to get energy out of this low intensity radiation source. The Solar Cells are made by purifying the Silicon to 99.9999% purity level. Purifying solids to this level is highly energy consuming activity and hence the Solar Cells are costly. Also, we need to use lot of structural materials due to the large area in which the panels have to be spread.

    All these make the Solar power not so cheap that it can compete with other sources to be eligible for grid connectivity with reasonable level of subsidy.
  • narsi
    Narsi - 
    @periasamykandasamy - To a certain extent, I agree with your inference. The current low prices are artificially deflated owing to manipulation by the Chinese. But that is not to say that there have been no significant price reductions. I think we can safely say that solar modules (crystalline) are at about or slightly less than $1/Wp, legitimately, which is still awesome.

    The 60 cents/Wp will most likely wont last. I think the price will stabilize at around 80-90 cents/Wp in about 6 months from now, and that will be a fairly good reflection of the actual costs...
  • periasamykandasamy
    Periasamykandasamy - 
    At 90 Cents / Wp, the cost per MW works out to Rs.4.95 Cr / MW ( 0.9*55*1000000). Normally, the Cell cost is about 50-60% of the PV Solar plant cost after installation. Hence, the overall cost / MW of installed capacity will be about Rs.9.0 Cr/MW.

    With a PLF of about 20%, we can expect 0.175 Crore Units per year. Interest for investment at 12% works out to Rs.1.08 Crore. The interest cost alone works out to Rs.6.17 per Unit. ( 1.08/0.175).

    With a life of 20 years, the depreciation works out to Rs.2.57 per unit [ 9/(20*0.175) ] . These two items put together comes to Rs.8.74.

    Still we have operating cost to be added, though there may not be much of maintenance cost.

    It is not clear how the PV cost can be Rs.6.20 per unit as claimed by some of the industry people.

    Well, if we can get cheap interest finance at say 6% for the entire Rs.9 Cr, then it may be break even at Rs.6.20 per unit.
  • barani
    Barani - 
    Power Finance Corporation, IREDA etc I believe offer project loans at lower rates like 6%. However, I agree, it is not a feasible project otherwise. The 20 year performance is also not guaranteed. In large scale, Solar projects are still not viable, in my opinion. India needs more rooftop and other self-reliant solar systems, than this grid-dependent solutions.
  • narsi
    Narsi - 
    In my estimate, the total capital cost per MW will be about Rs 7 crores by end 2014. Add to this, the following: Accelerated depreciation is available (80% first year). It is also possible to get loans at about 8% (adding exchange rate and other risk premia) through financial institutions if the developer uses modules from countries such as US or Germany...also, there is a 10 year tax holiday if I remember right.

    The lifespan is 25 years, acceptable at least for crystalline...

    Opex is less than Rs 0.4 per kWh for large scale power plants

    All these together, I think we can expect the sustainable cost of solar power to be around Rs 6.5 per unit beginning 2015...
  • periasamykandasamy
    Periasamykandasamy - 
    So, for the solar power cost of Rs.6.50 per unit, the following are prerequisites :

    1) The capital cost per MW shall fall to Rs.7 Cr. 

    The PV Cell cost itself is Rs.4.95 Cr / MW as seen from your Mail ( 80-90 cents / Wp). Is it possible to get land, the steel and other structurals, transformer, in-house electrical systems, installation, etc in the remaining Rs.1.05 Cr ?

    2) 80% Accelerated Depreciation benefit is not available to other sources like Coal / Nuclear. Let this be known to all. Many do not know that this is an indirect subsidy available only for renewables. This brings down the investment by the promoters by about 25%. This was available for Wind for the past 10 years and now withdrawn and instead GBI has been introduced. 

    So, this cost reduction is by subsidy. It does not reflect the actual cost.

    3) If we are able to get some external funding at 8%, as part of international support for " Green power", it is well and good. But if loans from Indian financial Institutions at lower interest rates is utilized, then it does not reflect the actual cost of Solar power.

    With 8% interest, interest part works out to Rs.3.20 per unit with an assumed investment of Rs.7 Cr / MW.

    4) Well, let us take lifespan for Crystalline as 25 years. What about the cost of crystalline ? Does it still works out to Rs.7 Cr / MW only or different ? Crystalline is costlier compared to Thin Film.

    5) Opex @ Rs.0.4 per Unit seems to be reasonable.

    Let us hope that all the above come true and we are able to get Solar power at Rs.6.50 per unit. Let it not be a disappointment like in Wind power.

    With respect to the 3000 MW TN Solar Power, if the unit cost works out to Rs.6.50, then TN people will be paying about Rs.3 per unit extra compared to the present average production cost of Rs.3.50 per unit. Hence, we will be paying Rs.1580 crores per annum extra, when the 3000 MW solar plan is completed [( 3000 x 1000 x 0.2 x 365 x 24) x 3].

    This number will go up by Rs. 526 Cr per year for every Rs.1.00 increase from the assumed solar power cost of Rs.6.50.

    This is fine. People can be asked to pay for a "Green Initiative". (How Green this "Green" is, when we take into account of the pollution of Silicon manufacturing, proportionate increase in steel consumption per MW compared to other sources, the Lead Pollution by Roof top users, etc is a point for debate.)

    But the main issue is that, by the time this 3000 MW of Solar power is installed in TN, about 3000 MW of the ongoing Coal / Nuclear power plants also will be commissioned. The then existing daytime shortage of 3000 MW would be comfortably met with these Coal / Nuclear plants itself. 

    Then where is the need for this 3000 MW Solar power plants which will produce only during day time ? 

    OK, can we dispense with the ongoing Coal / Nuclear plants ? 

    Unfortunately NO. 

    We need them anyway for night / peak hour load. This is NOT SO in Germany. Their peak load almost coincides with Solar power peak production time. Hence, there is some techno-economic justification for them.

    It is unfortunate that people seem to miss this simple fact while pressing for Solar power.

    Please note, no one is against Solar / Wind. Let the technology improve. Let it become atleast close to 25% grid parity level. 

    It is not any great technology that it takes time to develop / assimilate in India.

    But still if we want to use it for the sake of knowledge, let us go for stand alone Wind / Solar units in remote areas. Also, we can encourage CSP with hybrid solar / gas turbine stations with Combined Cycle, since the investment in these power plants are idling in day time.

    Still if we want to show that we are "Pure Green", let us encourage Solar PV / CSP in the already existing Wind Mill sites. This way we can effectively utilize the Wind Mill Land, Roads, Transformer, Electrical Systems, Grid, Manpower, etc. After all, Wind Mills operate only for 3 to 4 months in a year and that also at a maximum of 50 % capacity.

    Hope some one sees these discussions as NOT as arguments FOR and AGAINST Nuclear power and conveys it to the powers that be for right modifications in the TN Solar Policy.
  • narsi
    Narsi - 
    Very good post and analysis, Periasamy. Overall, I agree with your contention that we are some distance away (at least 30 years) before we can expect renewables to power a majority of our energy needs.

    The cost of Rs 6.5 per kWh is what I expect in 2 years time. Panel cost can be expected to be about 60 cents/Wp, so that would be about 3 cr per MW. The BoS costs will probably decrease very little, so that would remain at about 4 cr per MW, that was my basis for calculation.

    Yes, I am referring to crystalline modules...

    Your point on AD accepted, it is an artificial incentive, not sustainable... 

    Good debate going on here...

    See also my recent post on solar -
  • periasamykandasamy
    Periasamykandasamy - 
    Thus the reality is :

    1) The projected price of Solar PV after 2 years is Rs.7 Cr / MW.

    2) With the China Solar Cells "falling " price trend being arrested, even this Rs.7 Cr / MW may be difficult unless some technological break through happens. 

    3) The present price tag is Rs.8 to Rs.10 Cr/ MW.

    In view of the above, we must educate and prevail upon the Govt / Industry not to pursue the TN Solar Policy in its present form. 

    As already explained, by the time these Solar PV plants start feeding to the grid, we would have commissioned 2000 MW of Coal / Nuclear as well. This will solve the day time power shortage and make the Solar power redundant.

    Hence, as a long term solution based on the techno-economic factors, the Solar Policy shall be suitably amended to encourage :

    a) CSP Hybrid with Gas Turbine / Cogen Power Plants / Or for those who need only Steam for Process requirements, like Textiles, certain Chemical industries, etc. 

    b) PV Solar Hybrid with Wind Mills.

    c) CSP / PV / Wind Mills as Stand alone power source for remote areas where Grid connectivity is costly.

    If we earnestly try, we can get the "Green" funds at low interest rates even for these hybrids.

    If we go by public sentiment of "Why we should not use the freely available Sun Shine and Wind ?", TN will ulitimately end up in the same mess as we have ended up today by installing 7000 MW of Wind Mills and not investing early on to add a single MW of Coal / Nuclear power in the past 10 years !

    People do not want to understand the fact that we can not use Sea water for agriculture just because it is freely and abundantly available. It can be used for Drinking purpose with lot of money spent for making it potable. It can also be used in coastal power stations for cooling purpose. We can not afford to use it for agriculture.

    In the same way, Wind / Solar can only be used for specific applications with reasonable level of subsidies. If we attempt to use these sources for bulk grid applications, we will only be utilizing our scarce resources in the wrong way and cheat the public.

    Countries like Germany can afford to make Don Quixote exercises with their abundant resources. Also, their grid load pattern suits reasonably well to use Solar power. It is not so in India.

    It is the duty of educated lot like us to educate the public and the decision makers with right inputs. We must ensure that sentiments and prejudices do not play any role in techno-economic-social decisions.
  • narsi
    Narsi - 
    @Periasamy - I agree with you on the way solar should be architected

    Rather than look for just rooftop and grid connected, the modularity of solar (PV especially) should be utilised to arrive at optimal combinations with other power sources, and for areas where solar power makes most sense - for instance, decentralized power sources for villages with no grid
  • periasamykandasamy
    Periasamykandasamy - 
    Good ! We agree and close.
  • gvijai
    Gvijai - 
    Good news.
  • drashya
    Drashya - 
    @Periasamy - Sir, your intensive calculations are really great and have given a real insight as to some beliefs such as "100% renewable powered" are completely idealistic (at least in a foreseeable future!).

    I understand that I am still very inferior compared to your level, but still for the sake of getting my facts right at least, I would like to point out some of your notions which I consider to be a bit wronged.

    Firstly, Germany doesn't have more resources than us. We have multiple times the land, multiple times the sunlight (we're WAY closer to the equator), lesser per capita energy requirement (Germany being one of the most developed countries of the world) and multiple time the resources compared to Germany. I understand the size in this matter only increases complications and hence is a disadvantageous factor, but it has its own pros too. 

    Secondly, we still import about 98% of our cells (and a major share of modules too) if I am not wrong. Leave wafer manufacturing (which has 0% existence here), even making a solar cell from wafer is not done on a large scale in India. In such a condition, how can we imagine prices to go down? It is like developing a huge artificial industry in the US based on Indian subcontinent mangoes and then complaining about high prices!

    Third, computer chips require nine 9's of silicon purity while solar cells require six 9's (1000x lesser). So, if the computer chips industry can have a Moore's law, why can't we?

    Fourth, even renewable energy can never be 100% pollution free, because no matter how non-polluting or direct the energy source is, we will still be needing infrastructure to harvest that. Even to harvest the most direct energy source, i.e, lightning, we'll have to build an infra for its harvesting. And even if we manage to harvest any energy 100% pollution free, we'll still be operating iPhones and iPad on that! So, the point in using renewable energy is not to go back to the stone age, but to build a better world polluting it as less as possible.

    Fifth and most important, conventional energy sources have been in development for last 4 or 5 centuries (since Industrial revolution), so they have had their share of time for getting developed into efficient and reliable energy sources, while renewable energies have started giving them competition in just 4-5 decades! Conventional energies still need subsidies to become affordable, so what's so wrong if renewable energies are needing them too? I mean why the HELL are we so bent to make renewable energy 100% SUBSIDY free??! I mean subsidy is the money we pay the government to make things easier and affordable for us, right?
  • barani
    Barani - 
    Yes, this is the question that I asked long ago. If production of Solar Cells result in so much emissions that is "saved" in 25 years, is it really "renewable energy source"? Of course, that way there are no zero-emission power plants. However, one can crudely estimate how much emission is created from the infrastructure establishment, and how much it saves later. This is required before labelling any process as green technology.
  • narsi
    Narsi - 
    @Drashya - excellent post. Admirable passion and analysis from someone who is just in his undergraduate. How wrong I was to think that students' online activities started and ended with Facebook :-
  • barani
    Barani - 
    of course, it is a bad idea to invite risk at the cost of saving a few bucks, by importing from outside. For that matter, such dirty business tactics aren't exclusive to China. How about taking a look at our friendly America - they will dump GSM, 2G and 3G into India every few years *after* they themselves gone into 4G.. and we, like the familiar idiots end up importing all gadgets that comply with only old technology, thereby creating enormous e-waste. And that is not just for america. Huawei will dump routers and DSL modems that comply with only ip4, not ip6... and soon most of us have to buy "upgraded" routers and modems... all because we are the dumbest creatures who accept vintage obsolete technology. How about the "friendly" japanese dumping old automobile tech-nonono-nology into India, when the rest of the world is going towards hybrid, electric, hydrogen and other green technology vehicles? 

    India is being treated as the major dumping ground for almost every industrial sector. Thanks to Greenpeace, the French ship was stopped from unloading nuclear waste into India a few years ago. How many other times such dumping has happened without our knowledge? And the Russians are happy to sell us the 50 year old nuclear power plant technology only for some 25,000 crores, dirt cheeeeeap.... (some of our friends think so).

    if we treat ourselves low, we can't blame foreign forces from taking advantage of us. 

    Come on India, Wake the hell up! Stop looking at phoren countries as something great! We are the greatest minds, if only we would use it!
  • jaykrishnameher
    Jaykrishnameher - 
    @Barani- I agree with u. Untill we will develop the required technology or things in india, we will b paying high price and getting the old or the dumped things. 

    The same situation is for solar cells also. India should invest in the development of PV technology and in PV cell and module production to reduce the solar energy cost.

What the Buffett factor really means for solar

What the Buffett factor really means for solar

  • Warren Buffett
    Warren Buffett purchase of SunPower's two projects has caused a stir in the US solar industry. Image: Medill DC.

Of course it’s the indirect involvement of Buffett that has been the centre of the news frenzy rather than anything else, although the US$2 billion plus price tag gets noteworthy attention.The financial community and press have got themselves all worked up over SunPower’s success in selling two large-scale PV power plants to MidAmerican Solar, a subsidiary of MidAmerican Renewables and part of the billionaire investor Warren Buffett's business empire.
But does this really mean anything new and different for the solar industry?
No question it’s a great story for SunPower. The loss-making company can now better plan factory utilisation rates and lower manufacturing costs with improved demand forecasting over the next couple of years as the projects get built and milestones are reached, bringing in much needed revenue.
However, the deal alone would not return the company to annual profitability.
The deal must have been good for MidAmerican Solar as it has acquired the two projects. It will also give the energy firm a real insight into the IRRs and Levelised Cost of Energy of two mainstream competing technologies, both operating at the high end of large utility-scale PV in a high irradiance region as the company already owns a First Solar-built plant.
Hopefully over time the PV industry will get some valuable insight into the competing technologies’ LCOE’s, though I will not hold my breath too long on that.
What would be interesting to eventually uncover is which technology is ultimately providing the best IRR.
It is an interesting subject because SunPower touts its high-efficiency and tracker technology for providing the sort of kilowatt hour figures that enable its higher upfront module costs still to remain competitive with cheaper upfront-cost modules produced anywhere else in the world.
First Solar on the other hand is one of the lowest cost-per-watt producers and also touts its temperature coefficient advantages over c-Si technologies as evidence that its lower module conversion efficiencies can still be highly competitive with conventional modules. Lower power losses in higher climatic conditions than conventional modules are claimed to significantly narrow the overall kilowatt hour produced.
How this matches up to SunPower’s industry leading conversion efficiencies with the added boost from trackers, but impacted by temperature coefficient factors, is a masterful real-world technology test.
The fact that Buffett is involved may have a positive impact in the form of encouraging more investment in the downstream PV utility market. Finding investors has been the key problem since the financial collapse in 2009, yet module costs have fallen significantly thanks mostly to polysilicon price declines.
The Buffett factor could enable the 30GW-plus project pipeline in the US to pick up speed and see the country become the largest installer of solar, a moniker that has been touted for far too long and never happened.
Without more investors the fear is that much of the pipeline in the US will never be fulfilled and that the short but important phase the industry is in now of massive project sizes will rapidly be built-out but gone forever.
The SunPower projects have been known about for several years and are already factored into demand-side industry modelling. So let the financial community celebrate but it’s really business as usual for the PV industry struggling to control and match manufacturing capacity with demand.

Thursday, January 3, 2013

Warren Buffett to build world's largest solar energy project

Billionaire US investor Warren Buffett is taking a $2.5bn (£1.5bn) bet on solar energy, acquiring what is set to become the largest photovoltaic development in the world.

Installation of solar panels near Freiburg im Breisgau, Baden-Wuerttemberg, Germany, Europe
Construction for the projects - with a combined capacity of 579 megawatts - will begin in the first quarter of 2013 Photo: Getty Images
Mid American Energy Holdings, a subsidiary of Mr Buffett’s Berkshire Hathaway investment company, has struck a deal with SunPower to acquire and build two projects in California’s Antelope Valley.
The deal, which will see MidAmerican pay between $2bn to $2.5bn, marks the third time in little over a year that Mr Buffett has ploughed cash into solar energy.
He last year created a unit within Mid American to support an increasing number of solar and wind investments.
Work on the projects will begin within the next few months and construction is expected to be completed by the end of 2015.
SunPower, which is 66pc-owned by France’s Total, will remain involved in the construction and operation of the projects.
“Customers, investors and banks see this as a stamp of approval on SunPower,” SunPower’s president and chief executive, Tom Werner, said.
“It’s a huge deal for us, roughly the size of our company.”
SunPower, based in San Jose, California, has a market value of $732 million.
The two projects acquired by MidAmerican will have a combined capacity of 579 megawatts (MW), creating the largest solar photovoltaic power development in the world.
The scheme is expected to create about 650 construction jobs, SunPower said in a filing with the US Securities and Exchange Commission.
In December 2011 MidAmerican acquired another 550 MW solar plant in California from First Solar in a deal valued at an estimated $2bn.
Shortly before the First Solar deal, the investment group also swooped on a 49pc stake in a $1.8bn project in Arizona.
In total, the Berkshire Hathaway subsidiary has more than 1,830 MW of assets, also including wind power, geothermal, and hydro projects.
California is the biggest solar market in the US.

Source - Telegraph