Will Crystalline Solar Kill Thin Film? A Conversation with Applied Material’s Solar Head Charlie Gay

By Neal Dikeman

I had a chance to chat today with Dr. Charlie Gay, the President of Applied Material’s solar division.  You may recall, we broke the story in the blogosphere 5 years ago about Applied’s entry into solar, which was anchored with a highly touted and very aggressive strategy for turnkey large format amorphous silicon and tandem cell plants called SunFab.

Charlie reminded me that when they began 5 years ago, they did so along two major thrusts:  The acquisition of Applied Films in June 2006 getting an inline coating system for deposition of silicon nitride passivation layers on crystalline and in parallel an internal project to adapt their large flat panel display manufacturing technology for photovoltaics.

They still like the large module format, for a simple reason, cost in the field for large scale solar farms is heavily about getting area costs down relative to power output.  I was excited for another simple reason, when major capital equipment developers get involved, manufacturing maturity is not far behind, it forces everyone to rethink scale in different ways.

After a huge initial splash outselling everyone’s expectations in that SunFab concept, many industry analysts later kind of wrote them off as flash in the pan when they were reported having problems as implementations came in slower and smaller and harder than expected on their SunFab lines a couple of years ago, and a saw a major restructuring in 2009. But they’ve had success with that product anyways, EVERYONE saw a major restructuring in 2009, and more importantly the original vision of leading solar into mass manufacturing is still going strong, now across a range of products and technologies in thin film and crystalline manufacturing equipment.  Let’s put it this way, in their annual report they call themselves the largest equipment manufacturer to the solar sector, they have $1.5 Billion in annual revenues in the Energy & Environmental division, which is heavily PV, and there are like 120 mentions of the word solar in their annual report, almost once per page.

So what I really wanted to talk to Charlie about was the future of PV manufacturing. He frames the future by drawing a mirrored parallel between photovoltaics and integrated circuit manufacturing, beyond just semiconductors:

  • In IC, dozens to hundreds of device architectures exist, but basically one material, silicon.
  • In PV, there is essentially one architecture: the diode, but dozens to hundreds of material choices.

But silicon has been the mainstay material of PV for a number of reasons.  So we got into one of my favorite topics, the manufacturing improvement potential in crystalline silicon.

His version of Moore’s law for solar runs like this:  the thickness of the solar cell decreases by half every 10 years.  Today it’s 180 microns thick.  The practical possibility exists to get down to about 40 microns, with some performance improvement by making it thinner, but we can’t go much below 40 without being too thin to absorb enough light.  This fits with other conversations I’ve had suggesting that over the past couple of years most of the major crystalline solar manufacturers were working on paths to take an order of magnitude out of cell thickness.

If this comes to fruition, crystalline can literally wipe the floor with the existing thin film technologies.  Basically think sub $1 per watt modules with the performance of high grade crystalline modules today.  And as cost per watt equalizes, that higher efficiency starts to really tell, as since Balance of Systems costs have fallen at 10-12% per doubling of installed fleet, compared to module costs falling at 18-20%, in a world where BOS increasingly matters, the old saw about lower area cost per unit of power installed starts to actually bite for once.  Think ultra thin high performance low cost large format x-Si modules with fancy anti reflective coatings and snazzy high grade modules with on module inverters or DC optimizers mounted on highly automated, low cost durable trackers.  Think solar farms approaching effective relative capacity factors of 2.5-3 mm kW Hours per year per MW on 25 year systems at $2-3 per Watt installed.  Possibly the only thing on the planet that could match shale gas.

In fact, the entire thesis of thin film as a business and venture capital prospect has been built on the premise that crystalline material costs were just too high to get to grid parity. I’ve got scads of early thin film business plans touting that.  That thesis is under extreme pressure these days. I’d submit that if the industry 7 years ago had really understood how much improvement could be had, we’d have saved billions in potentially stranded thin film development.

Charlie says there are about a dozen different paths for enabling 40 micron cells.  The most interesting approach to him is an epitaxial growth process on reusable silicon templates.  A process which grows a thin layer of silicon on top of a reusable layer of silicon, using perhaps one mm thick silicon templates, etching the surface, and directly depositing silicon from trichlorosilane gas.  The idea would be to rack templates into a module array, grow the cells in an oven to your 40 micron level, then glue the glass module to the back side, and then separate it off to form a “ready to go assemble” module.  The challenge is basically oven and materials handling designs that get it cost efficient in high volume.

In essence, all you’d be doing is integrating a silicon ingot growth process directly into a module. Instead of growing ingots, cutting thick wafers, forming cells, then building modules from them, you grow cells racked into their own module personally instead of growing ingots first.

Hella cool.  A process like that means using fairly manageable capital equipment and materials handling technology development in known device and module technologies we could literally rip the ever living guts out of crystalline manufacturing costs.  And there are 11 more paths to play with???

The way he thinks about it, on a broader perspective more people are working in photovoltaic solar R&D today, by his estimate some 70,000 researchers and $3 billion per year, than in all of the prior PV history.   And that means whereas perhaps five main innovations over 35 years drove almost all of crystalline PV manufacturing costs (screen printing, glass tedlar modules, adapting steel from tires for cutting wafers, silicon nitride processes, and fast metrology tools), in today’s world, Charlie thinks we see 5 equivalent innovations in PV manufacturing technology every 2 years.

So I asked him to comment on whether there were parallel cost-down opportunities for thin films or whether it is an also ran waiting to happen.  He thinks there are.  He mentioned organics.  I pushed back hard, as organics have been written off by almost everyone for never seeing yield or performance, so where does he see the opportunity?  He responded that he picked organics to keep me from narrowing the materials field prematurely to just A-Si, CdTe, CIGS, and GaAS.  Silicon just like carbon can surprise us, e.g. bucky balls, carbon nanotubes, and just because early materials had stability and process issues, doesn’t mean we’ve exhausted the opportunities.

He says what he wants us to recall is that we are currently operating in PV manufacturing today with the materials that were on the radar in the energy crisis from 1974-1980.  That is changing in the lab and universities these days.  And given time the results will surprise us.

He draws a parallel between photography and photovoltaics, both invented in 1839, both rely on sunlight acting on materials. In photography, people started off putting films on glass, then putting films on mylar, and running things continuously.  Implying that in solar, we’re still on glass c. 1890.

He said to think about the original Ovonics/Unisolar vision in thinking about how you get to high speed continuous processing with thin film (think paper manufacturing, where done roll to roll it’s far more consistent than one-offs can be done).  If that is still our ultimate thin film paradigm (got to love the chance to use the word “paradigm”), the stars are still in front of us with what thin film COULD do.  And while roll to roll has had significant materials technology and process control challenges for the current class of materials, let’s go back to the mirror parallel to integrated circuits, in photovoltaics, one main device, scads of material options.  Just a matter of R&D hours and time.

He markedly did NOT suppose that the current state of thin film devices could beat 40 micron crystalline silicon by themselves.  It’s worth considering that we may look back and find that thin film, CdTe and First Solar were the stepping stones to 40 micron crystalline, not the other way around.  Maybe my next question to Charlie is whether he and I should set up Neal and Charlie’s 40 Micron Solar Company of America yet. 😉


Solar Powers more Vehicles as Gasoline use Drops

By John Addison. Solar is powering more vehicles. American’s have reduced their use of petroleum 5 percent this year. So far, petroleum reduction is the result of fewer miles traveled solo as people cut travel to deal with high gas prices and a slowing economy. At the margin, however, solar power is replacing oil.

There are now 40,000 electric vehicles in use in the United States. They are primarily the 25 mile per hour light electric vehicles. Fleets are starting to use heavy electric vehicles, and plug-in hybrids, that formerly required copious gallons of diesel and gasoline. In 2010, consumers will start buying freeway speed electric vehicles.

The U.S. Marine Corp at Camp Pendleton, during my last visit, showed me an 8-station solar car port that they use to charge their 320 light-electric vehicles. Petroleum fuel is a multi-billion dollar part of the U.S. Defense budget. Once the solar panels are installed, however, the sunlight is free. Solar is increasingly also used by the Marines and Army for stationary power in the U.S. and Iraq, reducing the need for petroleum in the form of diesel and JP8 jet fuel for running gen sets to air condition tents and buildings.

Every 44 minutes, sufficient energy from the sun strikes the Earth to provide the entire world’s energy requirements for one year, including the energy needed to move vehicles. Solar power grows 40 percent per year, as we become increasingly efficient at turning sunlight into electricity and heat.

Most importantly, with continued innovation and larger scale manufacturing, the price of solar keeps dropping. There is enthusiasm for advancements in photovoltaics (PV) and for large-scale concentrating solar power (CSP). As I researched and wrote this article at the Solar Power 2008 Conference, last week, the evidence of growth was everywhere. 17,000 from 92 countries attended the conference in San Diego, California. 425 companies exhibited, with 450 more turned away due to lack of convention floor space.

8 GW of solar power are now installed. Deutsche Bank forecasts that the photovoltaic market will growfrom $13 billion in 2006 to $30 billion in 2010. Polysilicon supply is expected to triple by 2010. New technology continues to delivers more electricity output with less silicon. These technologies include thin film, high efficiency PV, organic, concentrating PV and balance of system improvements.

For those interested in transportation, one notable area of growth is solar covered parking structures – a cool solution for a planet that is getting hotter.

When California Governor Arnold Schwarzenegger opened the Solar Power International conference, he highlighted Applied Materials’ 2 MW solar power that also shades their parking lot. The vast solar shading is designed to efficiently capture energy using SunPower 19% efficient panels implemented horizontally with a system that rotates the panels to track the sunlight.

Envision Solar specializes in solar parking structures. Designed by architects, Envision uses biomimicry to have parking structures that suggest groves of trees. NREL in Colorado uses an Envision solar carport with a charging station for two vehicles including its plug-in hybrid and EV. Other organizations have installed Envison solar parking structures with the support poles pre-engineered with wiring for future charging or integration of nighttime energy-efficient lighting. These organizations include the University of California San Diego and major solar panel maker Kyocera.

New Jersey Transit is preparing for a future where parked cars can be charged with sunlight while people use public transportation. Premier Power Renewable Energy recently completed the first of two 201kW solar canopies, on the rooftops of two large six-story parking garages at the new Trenton AMTRAK Transit center. Each project includes more than 600 solar panels. The solar systems will eliminate approximately 141 tons of CO2 emissions annually.

The New Jersey parking structures are also equipped with 110v charging stations for Plug-in Hybrid Electric Vehicles (PHEVs) and Electric Vehicles (EVs). Participating in the October 14 ribbon cutting was the Mid-Atlantic Grid Interactive Cars (MAGIC) consortium, which includes the University of Delaware, Pepco Holdings, Inc., PJM Interconnect, Comverge, AC Propulsion and the Atlantic County Utilities Authority, created to further develop, test and demonstrate Vehicle-to-Grid technology.

At Google, part of their 1.6 MW solar PV installation is a solar carport structure that includes charging stations for Google’s plug-in hybrid converted Toyota Priuses and Ford Excapes.

The conference included many lively debates about whether the financial crisis would stop solar’s growth in 2009. Large projects usually require millions for project financing. Allowing customers to pay by the kilowatt with power purchase agreements requires long-term financing. Illiquidity will surely slow growth.

In most U.S. states, however, electric utilities are required by law to expand the percentage of power that is delivered with renewables. In California, for example, the renewable portfolio must be 20 percent by 2010. Pacific Gas and Electric is installing 800 MW of utility scale solar PV to meet part of that. Arizona Public Service has contracted with Abengoa to install 280 MW of concentrating solar thermal that includes molten salt towers to store six hours energy for delivery during peak hours.

Utilities have deep pockets and these volume projects are lowering costs. With illiquidity in other sectors, utilizes will increasingly drive centralized solar. In areas with positive regulatory environments and with robust grids, utilities will also encourage decentralized solar PV as part of their mix.

United States power utilities spend $70 billion annually for new power plants and transmission, plus added billions for coal, natural gas, and nuclear fuel. For $26 to $33 billion per year investment, ten percent of United States electricity can be from solar by 2025, details the Utility Solar Assessment Study, produced by clean-tech research firm Clean Edge.

By 2050 solar power could end U.S. dependence on foreign oil and slash greenhouse gas emissions. In their Scientific American article, Ken Zweibel, James Mason and Vasilis Fthenakis detail the scenario. A massive switch from coal, oil, natural gas and nuclear power plants to solar power plants could supply 69 percent of the U.S.’s electricity by 2050. This quantity includes enough to supply all the electricity consumed by 344 million plug-in hybrid vehicles.

The price tag for the transition would be $400 billion, but this could be spread over a number of years. Should this seem too expensive, consider the alternatives. This is a fraction of what the U.S. has spent for the war in Iraq.

In the final keynote of the Solar Power International conference, U.S. Senator Maria Cantwell (D-WA) explained that both Republicans and Democrats ultimately supported an 8-year extension of solar and other renewable investment tax credits in the Emergency Economic Stabilization Act of 2008. This bill also included $7,500 tax credits for the purchase of new plug-in hybrid and electric vehicles. Senator Cantwell also strongly supports United States investment in a smart and robust grid, and in bringing high-voltage lines from major sources of renewable energy to major markets.

The transition to clean energy is increasingly recognized as an excellent investment. Due to rapid cost reduction, solar is a growing part of the solution that includes electric vehicles, energy efficiency, wind, bioenergy, geothermal, and other renewable sources. Compared to business as usual with oil and coal, renewable energy is downright cheap. The International Energy Agency estimates that by 2030, $5.4 trillion must be invested to increase global oil production.

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John Addison publishes the Clean Fleet Report and writes about cleantech and renewable energy. He has a modest stock holdings in Abengoa and Q-Cells.

Tech Giant Intel Joins IBM and Applied in Big Solar Bet

Following on the 2006 and 2007 announcements of technology giants Applied Materials and IBM moving into the solar sector, Intel has joined the fray in 2008 with the spinout of SpectraWatt, its newly created solar division.

I had a chance to chat with Andrew Wilson, a longtime Intel guy who is the CEO of Spectrawatt, about what he is doing. The venture is the result of the last 3 years of extensive business planning, that Andrew said grew out of an off the cuff conversation he had internally four years ago.

While they have very early stage development in the works for some new and novel technology to reduce the manufacturing costs of solar cells, they are not sharing details. The Spectrawatt core business today will be about building a company to manufacture crystalline silicon based solar cells. In the near term the business will be buying wafers and manufacturing cells. According to Andrew, they have a significant supply of silicon secured, and while he cannot say who the vendors are, at least one of those vendors will likely be announcing soon, as the Spectrawatt contract is a material event for them.

So the first question is why x-Si and not thin film? Besides the obvious that it is far and away the biggest market today and a natural fit for Intel, Andrew added two more. Customers care about per kwh cost, and all things equal, how much energy they can get out of the real estate they have (read, efficiency matters). So they think x-Si makes a lot more sense than thin film, especially given the additional issues around stability, manufacturing complexity and materials resource constraints.

Andrew did say that they may vertically integrate later. So I asked why did they start at cells? Andrew explained that since the business comes out of Intel, and Intel is accomplished at processing wafers into products, cells made sense to start with. And at the end of the day they hold the view that the biggest point of value in solar value chain is in creating the cell, moving from low value silicon to high value device. They consider it the largest single value add step.

Andrew and I are in agreement that 2004 was a kind of a magic year changing what the photovoltaic industry is. Andrew stated it was the first year where the average company in every segment of the value chain in solar became profitable. So given today’s environment Intel and Spectrawatt could have conceivably started at numerous places in the value chain. This is where the vertical integration may come in. His view on the silicon supply is that no glut is coming, or at least not a long lived one. The end demand market is growing at 30 to 40% per year, and the silicon supply that is coming on line is in large part subject to long term contracts with fixed prices. The silicon supply additions then are pretty much already spoken for. In Andrew’s mind while growth at the margin will definitely cause some level of boom bust cycles, those long term supply contracts may moderate it more than other people believe. If he is right, and he has secure supplies, a horizontal business like cell manufacturing is a great place to be. If he is wrong, he sees continued vertical integration to manage the growth issue as one of the major avenues industry participants will go done. In this he and I also agree, rapid movements in supply cycles tend to reward vertical integration. And if he gets big enough with Spectrawatt, vertical integration could be a move Spectrawatt makes, too.

It is great for the solar industry to see more technology giants like Intel joining the fray, and perhaps helping drive down crystalline product costs the same way Applied Materials and IBM are looking to drive down then film costs.

Neal Dikeman is a founding partner at Jane Capital Partners LLC, a boutique merchant bank advising strategic investors and startups in cleantech. He is the founding CEO of Carbonflow, founding contributor of Cleantech Blog, a Contributing Editor to Alt Energy Stocks, Chairman of, and a blogger for CNET’s Greentech blog.