Photovoltaics World asked industry executives and technology experts to comment on the trends and market forces they see driving PV technology in 2011. The experts see both a diversification in technologies and a growing need for sophistication in manufacturing equipment.
Sarah Kurtz, Principal Scientist and Reliability Group Manager at NREL, expects increases in CPV and thin film, while silicon will continue to be strong, especially for applications that value long lifetimes. Looking ahead, her expectation is that PV systems will deliver electricity for a low enough cost to be used as a mainstream energy source.
Chris O’Brien, Head of Market Development at Oerlikon Solar, observes that uncertain c-Si cost and price outlook will likely spur renewed interest in thin-film technology alternatives. Though he echoes the analysts’ consensus that the U.S. market will be in the top three within the next few years, he cautiously observes that this market opportunity is highly competitive and many of the announced PPAs will require PV system prices that are significantly lower than today’s prices. “This creates a large opportunity for thin-film technologies, assuming that they establish and maintain a demonstrated advantage in system prices and levelized cost of electricity (LCOE),” says O’Brien.
Applied Materials’ CTO, Chris Eberspacher, sees the continuing reductions in wafer thickness and anticipated increases in processing steps and wafer moves as accelerating the move to more factory automation. He predicts that higher efficiency cells will require moving to more sophisticated device designs and more complex process flows that require 10-15 or more core process steps, compared to 6-8 core steps today.
Also seeing the need for more equipment sophistication is DEK Solar’s Darren Brown. He envisions a real demand for innovation in both process and equipment technology, along with minimizing downtime. Brown expects an increasing demand for fine-line printing, pattern recognition technology, and metal wrap-through (MWT)/backside contact cells.
In 2011: Diversification of PV Technologies
Sarah Kurtz, Principal Scientist and Reliability Group Manager at NREL
Being a PV prognosticator is not for the faint of heart. The demise of silicon and rise of thin-film PV have been predicted for more than 20 years, but guess what? Silicon still dominates the PV market.
First Solar has realized the vision of thin-film PV, growing in just four years from ~25MW/yr to its current rank as the largest PV manufacturer in the world. Its success leveraged ~15 years of development and benefited from the shortage of silicon feedstock when PV’s use of silicon surpassed that of the electronics industry. More than 100 PV companies are poised in the wings attempting to match First Solar’s success, with many making strong progress, though often failing to satisfy the naturally impatient venture capitalists.
In the meantime, concentrating PV (CPV) was written off in the 1990s because of the community’s belief that the future belonged to building-integrated PV (BIPV); investment in CPV was almost nil in a PV community that dismissed the probability of utility-scale applications. The recent trend toward PV installations >10MW (with many ground-mounted and an increasing number owned/operated by utilities) has revived interest and investments in CPV. High-concentration PV can use 40%-efficient solar cells, resulting in CPV modules with ~30% efficiency compared with the more common 15%–20% for silicon and 8%–14% for thin film.
Looking toward 2011, a handful of CPV companies will grow to tens of MW of production, while a growing number of thin-film companies are positioned to increase from tens to hundreds of MW. Whether these new technologies gain market share depends on both their technical progress relative to silicon PV and the applications that dominate the market. The technical mix of the PV industry may continue to evolve for a hundred years. Strong utility involvement could increase the use of tracked technologies—because utilities can shave peak power demand with PV production late in the afternoon on hot days.
Many companies are working diligently on BIPV products that could replace building components, improving the benefit/cost ratio for thin-film shingles and other BIPV products, while avoiding the need for new transmission lines. As incentive programs shrink, the benefits of low-cost approaches become central, emphasizing reduction of installation and other balance-of-system (BoS) costs.
In the end, will PV systems deliver electricity for a low enough cost to be used as a mainstream energy source? I believe the answer is “yes.” Just as the Edisonian light bulb has been reduced in cost to pennies per bulb, the cost of today’s PV technologies can and will be reduced.
A key differentiator between PV and most other electronic products is that the efficiencies available in the future will be only slightly better than those of today (20% for flat plate and 30% for CPV). A world that has grown accustomed to replacing computers every few years naturally expects to replace PV panels with the latest and greatest. But why replace your modules if the new product is lower in cost, but similar in efficiency? High efficiencies have already been achieved, so the opportunity for the greatest improvement in performance may be related to reliability. Current warranties are ~25yrs. Evidence suggests that modules could be made to last 100yrs. If so, this factor-of-four relative improvement would reduce the effective cost of utility-owned PV electricity, though may be meaningless to private PV owners who may move or replace a roof in <10yrs.
In the coming years, expect PV technology to become more diverse with increases in CPV and thin film, while silicon continues to be strong, especially for applications that value long lifetimes.
Watch for Decreasing Subsidy levels, U.S. Market Expansion in 2011
Chris O’Brien, Head of Market Development, Oerlikon Solar, Trübbach, Switzerland
Converging costs between thin film and c-Si…or not. The past two years have seen a significant convergence of costs and prices for thin-film and crystalline modules. Looking ahead to 2011, there are conflicting data about the outlook for c-Si prices. On the one hand, leading c-Si manufacturers have announced significant increases in capacity for 2011, as well as new technologies that will increase average conversion efficiency. At the same time, 2010 market prices for c-Si have been flat or increased, as a result of constraints in some parts of the relatively complex c-Si value chain. Uncertain c-Si cost and price outlook will likely spur renewed interest in thin-film technology alternatives, as these technologies continue their steady progress along relatively steep learning curves.
Decreasing subsidy levels…opportunity for least-cost thin-film technologies. In the aftermath of a year where actual installations in leading markets (Germany, Italy and Czech Republic) will be much higher than policy makers’ targets for growth, incentive levels for 2011 will be revised downward in an attempt to balance industry growth with public expenditure. This reduction in incentive levels will place pressure on all PV suppliers, and is expected to create an opportunity for least-cost thin-film PV systems. A revised market outlook, with much lower incentive levels, will also accelerate the “churn” of manufacturing capacity, creating an opportunity for suppliers of technologies that have a cost-of-ownership that is competitive with future market conditions. A reduction in incentive levels in leading markets will also result in more uniform module average selling prices across markets, with reduced opportunity to cross-subsidize across geographic markets.
U.S. market expansion – opportunity for thin film, but near-term policy and finance risk. There is widespread consensus that the U.S. market is likely to be among the top three global markets within the next few years. The (7GW) backlog of announced utility-scale PV projects is a clear illustration of the enormous market potential in the U.S. Less obvious is that this market opportunity is highly competitive and many of these announced PPAs will require PV system prices that are significantly lower than today’s prices. This creates a large opportunity for thin-film technologies, assuming that they establish and maintain a demonstrated advantage in system prices and levelized cost of electricity (LCOE). At the same time, the scheduled expiration of the Sec. 1603 Treasury Grant program at the end of 2010 will result in a sharp setback to market growth in the U.S., as a shortage of available tax equity will lead PV project developers and investors to delay and cancel many of the projects that have been announced. The solar industry, led by SEIA, is pressing a strong campaign to ensure an extension of this key federal incentive program.
Accelerating Efficiency Improvements, Cost Reductions
Chris Eberspacher, Chief Technology Officer, Applied Materials Solar Products, Santa Clara, CA USA
The solar photovoltaics (PV) market continues to present tremendous growth opportunities. In 2010, PV installations are expected to double year-over-year to over 14GW and by 2013 the market could exceed 30GW. Year-by-year the installed cost of solar PV continues on a downward cost curve, making peak power parity a reality today in many markets around the world.
We see the PV industry implementing a continuum of leveraging improvements. For example, two major trends for further increasing module efficiencies are optimization of the front and back electrical contacts, and a simultaneous drive to all back contact cell structures. Optimization is achieved in many steps: 1) leveraging the existing backbone of low-cost screen printing tools by printing narrow contact lines to maximize the amount of light entering the solar cell and by printing dopants to form selective emitters to generate higher currents and fill factors; and 2) leveraging high-volume vacuum deposition processes to deposit high-quality passivating layers on the back of the cell to minimize recombination losses. In parallel, there is a drive to put all of the contacts on the back of the cell to maximize the amount of light entering the cell, simplify the metallization process, and put all of the contacts on a common plane to facilitate high-yield automated assembly of high-efficiency modules.
In addition, we see significant advances in factory automation, integration, monitoring and control, with the increased use of on-line real-time metrology to maintain optimum tool operation and maximize factory output. Advanced factory automation and control systems are increasingly becoming the norm as factory operators better understand the leverage of real-time automated factory control in minimizing yield losses and maximizing average cell and module efficiencies.
Looking into the future, to fabricate future higher efficiency cells, manufacturers are moving to more sophisticated device designs and more complex process flows that require 10-15 or more core process steps, compared to 6-8 core steps today. The result is that the number of tools will increase, and the number of wafer movements will increase, perhaps by as much as a factor of ten. At the same time, wafer thicknesses are likely to decrease from ~180μm today to 120-140μm in the not too distant future. The combination of continuing reductions in wafer thickness and anticipated increases in processing steps and wafer moves will accelerate the shift to further factory automation.
These are but a few of the advances that we are driving on our c-Si PV roadmap. We anticipate continuing rapid growth, accelerating efficiency improvements, and significant manufacturing cost savings as these and other advances are adopted in large-scale manufacturing. After more than three decades of steady improvement, the outlook for further PV technology improvement remains bright.
2011: The Year for CPV to Make Big Inroads into Utility Installations
Nancy Hartsoch, VP Sales and Marketing, SolFocus,
Mountain View, CA USA;
Chairman, CPV Consortium
In the past six months, many industry experts have asked the question – is 2010 the year for concentrator photovoltaics (CPV) to turn the corner on commercialization? A quick look at CPV’s progress in the past year will shed light on that question.
For a solar technology to be considered commercial, it requires the technology to be accepted and deployed in commercial projects. Getting to that state typically means several metrics are achieved. First, a CPV technology company must be able to prove that its predicted performance is in line with its actual performance. Along the same lines reliability of the products must be proven, with a key ticket to entry being certification to international standards – for CPV this is IEC 62108. Lastly, the products must be available with volume manufacturing and proven fieldability.
For all of the above criteria, a few CPV companies have achieved all of these milestones and another handful has achieved at least some of the key metrics of commercialization. Looking at 2010, shipments of CPV systems is forecasted to be between 10-15MW. Several projects of the 1MW scale were deployed, and projects as large as 30MW have been announced for completion in 2011 and 2012. Certification to IEC 62108 standards has been achieved by two CPV system manufacturers and in at least five projects, CPV technology was selected in competitive bids against leading mono-crystalline, poly-crystalline, and thin film products. There are now CPV suppliers who can provide extended field data on their systems, with validation of actual field performance to forecasted energy projections. Lastly, CPV is being manufactured in automated high-volume factories with a reported total industry capacity of 150MW globally.
CPV has turned the corner on commercialization, so where to from here? 2011 will be another milestone year for the industry with CPV moving from smaller distributed generation projects to utility-scale deployments. CPV is an ideal technology for utility scale or “big solar” for a number of reasons. CPV systems offer system efficiencies around 26% compared with silicon PV from 14-19%, and thin films from 8-12% efficiency. Higher efficiency means less equipment is required to generate a given amount of power. These performance numbers combined with high energy yield results in CPV providing the lowest cost of energy of any solar technology in solar rich regions. One of those key regions is the Southwest U.S. where there are over 800MW of utility-scale solar projects currently in the proposal or pending contract stage. These are the areas where CPV can provide a cost of electricity at 10-20% lower than other solar approaches.
These CPV plants are highly scalable and capable of being deployed very rapidly, requiring months instead of years to operation, as is the case with concentrating solar thermal or CSP plants. The power plants can be brought on-line in phases, allowing a project to begin generating revenues even before the project is complete. Fast time-to-cash in a utility-scale environment reduces the cash flow requirements and improves the overall economics and funding of solar projects. CPV also provides its high energy yield and low electricity costs without the use of water to generate electricity. With the water concerns of the desert regions, this is an extremely valuable benefit for CPV, allowing preservation of water reserves and potentially faster permitting for projects. Also worth noting is the ability of CPV system manufacturers to scale manufacturing capacity rapidly with low capital investment. With rapid scalability and low capital expenditure requirements, CPV technology is extremely well positioned to move from its distributed generation deployments today into the volume demands of large distributed generation and utility-scale projects in 2011.
Healthy Growth − Even with Subsidy Scalebacks
Tom Adcock, Global Marketing Manager for Photovoltaic Solutions, Henkel, Irvine, CA USA
With governments around the globe taking an active role in encouraging (read: subsidizing) R&D efforts, installations and infrastructure developments, the worldwide solar power market saw 49% growth in 2010 as compared to 2009. It could be argued, in fact, that the recession encouraged much of this with large percentages of stimulus funds earmarked for “green” initiatives. Nevertheless, the photovoltaics (PV) industry should not rest on its government-funded laurels – essential as these programs are for initial, widespread solar power use – but continue to drive even greater low-cost, high efficiency solutions that can compete with traditional grid power costs.
Though the efficiencies of both thin-film and crystalline-silicon (c-Si) technologies have improved in recent years, effectively converting even more of the sun’s power into usable energy will be required for continued growth of PV and mainstream adoption of solar energy alternatives. This requirement necessitates changes to current cell dimensions (i.e., larger, thinner cells) and the subsequent need for more efficient materials to interconnect the solar cells. For c-Si cells, solder’s dominance as a connection material may soon be challenged as potential lead-free processes are examined. Lead-free solders mean higher processing temperatures, which would introduce stress that new cell designs likely cannot withstand. Therefore, more flexible, electrically conductive adhesives (ECAs) are proving to be the most viable solution for advancing cell connection technology. ECAs have been the predominant connection material for thin-film solar cell assembly for some time, but are also now proving they may be the way forward for the future of c-Si as well.
Solar cell efficiency will also be improved through the use of new cell and module configurations such as back (or rear) contact solar cell processes, which encompass both metallization wrap-through (MWT) and emitter-wrap through (EWT) designs. The interconnection of these cells is also being facilitated by electrically conductive adhesive materials, further illustrating the integral role of robust materials as an enabler of solar technology advance.
In 2011, new cell designs, advances in materials and higher throughput manufacturing techniques will continue to drive down the cost of solar, making installation more attractive and market growth very healthy, despite the scaling back of some government-funded initiatives.
Higher Efficiency/Yield Drive Demand for Equipment Sophistication
Darren Brown, Alternative Energy Business Manager, DEK Solar, Weymouth, Dorset, UK
In a fast-paced industry such as solar, predicting what the future holds is a major challenge. However, this ability is vital, since it is this information that informs technology leadership and ultimately, keeps end users competitive.
One of the main issues facing the solar industry in 2010 is cell efficiency. And, since grid parity is the holy grail of solar cell production, this issue will continue to dominate through 2011 and beyond. For example, there is currently increasing interest in technologies such as selective emitter and print-on-print, which enables cell manufacturers to print higher, narrower collector grid features onto the front of solar cells to deliver the high efficiency energy conversion capabilities key to future success.
Going forward, cell producers must respond to increasing demand quickly – which means that equipment must facilitate easy and quick scale-up, without impacting heavily on factory floor space. To get more desirable products from the end of the line – products that convert more sunlight, for example – there is a real need for higher levels of throughput and yield – without compromise. Essentially, as we move into 2011, we will see a real demand for innovation in both process technology and equipment technology, all backed by the experience and knowledge necessary to minimize downtime.
There is a recognition of the need for more sophisticated equipment with high functionality options. Advanced functionality capabilities are becoming more and more essential, with increasing demand for fine-line printing, pattern recognition technology, metal wrap-through (MWT)/backside contact cells. Solar equipment providers must now think beyond equipment. They must not only provide print platforms and in-house screen and stencil expertise, but match this with a global infrastructure and service commitment that end-users can employ to achieve ever-greater efficiencies.