Feature

PV technology developments 2011 and beyond


Joyce Laird

Part two: The industry needs to continue to innovate and address costs, so what are the equipment manufacturers doing to address this need?

The solar PV industry is maturing and while we hear a lot about solar power generation in all of its various technologies, the truth is, it still has a very long way to go to gain the market share it hopes for.

What affects the solar manufacturers should obviously affect the companies that supply them. However, because of the global reach of most materials and equipment suppliers, they are not tied to the foibles that affect any single geography…or any single technology. If the U.S. or EU go into a dive, and China and Africa start booming, it's simply a matter of selling to where the world is buying.

“The solar industry is still very young”, says Tracy Anderson, director of 3M's Renewable Energy Division. “It has the smallest market share of all forms of electricity generation globally. [But] it is the one with the brightest future. Every Government is pushing it and there is a lot of room for suppliers to work on ways to help the manufacturers.” 3M supplies PV, CIGS, thin-film and CSP technology manufacturers with materials that can help them increase the power from their products or installations, while addressing cost issues.

Kevin Chen, chief marketing officer for Applied Materials (AMAT) Energy and Environmental Solutions segment, says: “Europe leads the world in solar energy generation capacity because countries like Germany and Italy have well-designed feed-in tariff programmes. Now other countries are starting to adopt similar incentive systems to encourage adoption. China just announced its own national feed-in tariff system. Japan just passed theirs as well. India has a very lofty goal for the country to adopt solar. It's really becoming a true global product. As the industry matures, our customers will continue to be focused on how to get their manufacturing costs down, while improving the efficiencies of their products. This will continue to be the trend.”

Success or failure comes down to making correct choices. Dr. Thomas Christmann, director Business Development for Bosch Rexroth Semiconductor and Solar Group, says that these so-called correct choices - as well as the use of automation tools - could lead to reduced engineering time, which can “save from 25% to 50% over conventional installation costs”.

Chris O'Brien, head of market development, North America, Oerlikon Solar USA Inc says that the growth of the market for PV in the U.S. is supported by a foundation of favourable long-term policies, but is critically dependent on PV delivering electricity at prices that are competitive with alternative generation technologies, and also on the recovery and expansion of financing for PV projects:

“The market potential created by competitively priced PV PPAs [power purchase agreements] and growing RPS demands for renewable energy is well recognised by project developers in the U.S. In a recent conference presentation, a spokesperson for Edison Electric Institute estimated that there are 36 GW of PV projects that have been permitted or are in planning stages. This enormous backlog of U.S. PPA projects, driven by falling PV prices and competitive PV PPAs, is a promising harbinger for market growth in other regions of the world where electricity prices are considerably higher than in the U.S.,” O'Brien says.

Brooks Herring, vp of communications and operations for Solar Frontier notes that the solar market is extremely competitive: “It is going to take significant strength, scale, quality and technological advantage to come out on top. Japan, as a 100% importer of petroleum, has been keenly focused on renewables development, including solar, since the early 1970's…and took an early lead in technology advancement, taking full advantage of the…efficient and high quality manufacturing capability that the country is known for. The increase in global demand for solar has come with a greater focus on the fundamental goal of reducing the cost of kilowatt hours, not to mention understanding that significant ecological factors contribute to the long-term costs.”

The automation solution

From the PV automation side, everyone is doing their best to streamline production today. When looking at recent failures [read Solyndra, Evergreen Solar, etc., Ed.], those that have folded had good products, but had one thing in common – their products were highly unique. They required special equipment and special handling that was away from the norm. That made it impossible to compete with those that had products that could use effective, standardised manufacturing equipment and tools.

Since abandoning its SunFab a-Si thin film equipment line, AMAT now focuses on two main products: Chen explains, “we produce a wafering system and a line of screen printing equipment which produces the metallisation on the wafers. Together these two represent significant steps in the crystalline silicon solar cell manufacturing process.

“As the industry matures companies not only need to drive down their manufacturing costs to remain competitive but they need to increase their efficiencies in order to differentiate themselves from their competition.”

One example of how AMAT does this is their selective emitter, which Chen says can increase cell efficiency by as much as 0.7%: “It's a multi-step process that helps squeeze more efficiency out of the solar cell. Most solar cells have contacts that appear as fine lines on the front surface of the cell. Underneath these lines, there is a highly doped active region vs. a standard cell,” Chen explains.

“By putting this highly doped region underneath those contacts, you can boost the efficiency of the solar cell. It sounds simple but to accomplish the task requires extremely precise alignment of that doped region with the very thin contacts above it. Our Applied Baccini Esatto Technology platform enables this selective emitter alignment process with precise vision systems and image processing software,” he adds.

On the wafer side, the industry is continually trying to optimise the wafering process to improve cutting efficiency for higher throughput and reduced consumables and kerf loss: “We are innovating the wire technologies used in our platform by going from standard wire to what we call structured wire, which boosts the wafering productivity. The next step after that would be diamond wire which increases productivity even further,” Chen says.

When asked whether Applied may venture back into the thin-film area post SunFab [some customers are still using the lines successfully, Ed], Chen says the company continues to fund R&D programmes in that area, and supports customers who bought their thin-film equipment in the past, but that it is not part of their current business plan: “In any business, it is wise to look at your target markets and align your resources and capabilities to address those markets rather than try to be everything to everybody. Today, we are focused on bringing innovation and cost reduction to the c-Si market.”

Headquartered in Germany with divisions in 80 countries, Bosch Rexroth is well known for its automation equipment, software and components used for streamlining manufacturing processes in multiple industries. It opened solar divisions four years ago.

The Semiconductor and Solar Group focuses on OEM customers that service the PV market. This covers products such as linear actuators and bearings; electric drives and controls such as PCs, PLCs and motion controllers. It also provides pneumatics and conveyor belts specifically designed for transporting solar modules throughout the factory.

But Christmann says the company does not provide the complete automated lines, rather its automates the tools: “Our end customers are the equipment manufacturers such as Northfield Automation, Schiller and others. They integrate our technology as needed into the final machines and lines and ship these to solar manufacturers globally.”

Conveyors are a good example of standard products customised for solar. Christmann says that a solar conveyor must have high friction belts and low particle generation and needs to resist high temperatures.

“We also have a linear motion system which is basically an upside-down linear motor. In this case we keep the coils steady and move the magnets on the coils. This has major advantages; you don't have to carry any cables with the magnet because everything is connected to the coil. There are no moving parts except the pallet. Also, if you now put the magnets into a vacuum chamber and the coils are outside, it creates the perfect transport system. There are no feed-throughs necessary. There are no additional sensors needed between the magnets and the coils. It can feed right into the vacuum.”

Oerlikon Solar designs and manufactures field-proven equipment and turnkey manufacturing lines for the mass production of thin film-silicon solar modules. Headquartered in Switzerland, the company has 13 locations worldwide and maintains sales and service centres in the US, Europe, China, Taiwan, Korea, Singapore and Japan.

“Oerlikon Solar was the first to integrate the high-efficiency Transparent Conductive Oxide (TCO) layer, and the first to commercialise the high-efficiency Micromorph tandem technology process and support the majority of its customers in migrating to it. To date it is the only proven end-to-end Micromorph solution available on the market, offering lowest cost of electricity US$/kWh, and proving highest future cost reduction potential,” O'Brien says.

Oerlikon Solar's thin-film silicon product and equipment technologies also enable customers to achieve what Oerlikon calls the “lowest production costs in the PV industry”. Specifically, the Oerlikon Solar ThinFab reduces the manufacturing cost of thin-film silicon modules to €0.35/Wp, with 10.8% stabilised efficiency and 154 Wp module performance, according to the company [subsequently updated after the interview - ed].

Solar Frontier is a 100% subsidiary of Showa Shell Sekiyu K.K., Japan. It established the world's first Gigawatt-scale CIS module factory in 2011. Solar Frontier's CIS technology, denoting key ingredients copper, indium, and selenium (in addition to gallium and sulphur), has the potential to set the world's most enduring standard for solar energy, the company hopes.

Herring says: “Throughout our manufacturing process we use fewer natural resources and raw materials than crystalline-silicon production does. This translates into lower energy consumption and material costs; savings we can pass to our customers, along with a smaller carbon footprint per kW of production capacity and shorter energy payback time.”

In part three coming soom - Materials is another area where solar manufacturers are looking to improve performance and reduce costs.

About: Joyce Laird has an extensive background writing about the electronics industry; semiconductor development, R&D, wafer/foundry/IP and device integration into high density circuit designs.

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Comments

JUAN CARRERE said

14 February 2012
PV technology or power can be and actually is more than reachable when the cost of the energy (US$/kWh) in that country is high (higher in comparison to many countries).
Juan J. Carrère
Consultant

ANUMAKONDA JAGADEESH said

12 February 2012
In spite of constant improvements in PV Technology still the cost of generation of Solar Power is not within the reach of developing countries.
Dr.A.Jagadeesh Nellore(AP),India
E-mail: anumakonda.jagadeesh@gmail.com

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