PV Asia Pacific Expo addresses alternative solar technologies

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"Alternatives" are what most label solar energy as when talking about the various energy sources available in the world today. What is interesting is the fact that within the solar world, some technology forms are also listed as being alternatives to the rather prominent crystalline silicon.

What are the alternatives to the much-celebrated crystalline silicon? Will these alternatives ever come into major commercial play? What makes them bankable and who are the players working these sectors? These were just some of the questions posed during the second day of the Asia Pacific PV expo, currently being held in Singapore.

Much ignored

Alternatives in the alternative energy sector are defined as technologies like thin film and concentrated photovoltaics (CPV). Shanghai New Energy Industry Association’s Chief Representative of Europe Nabih Cherradi called them the "much ignored section of the PV industry".

Nabih who moderated the sessions on ‘Alternatives to crystalline silicon’ and the ‘Commercialization of innovative technologies’ posed the question of whether these alternatives can provide any leverage over crystalline technologies.

Why, he asked, would anyone switch from the well-established crystalline technology to the promising, but rather unstable technologies like thin film? Solar Frontier’s Ichiro Sugiyama highlighted his company’s success story, having placed its trust in thin film technology and made the bold and impressive 900 megawatt (MW) plant move.

Race for the right technology

Exotic alternatives are aplenty as Helmholtz Center Berlin’s Hans-Werner Schock highlighted. He placed cadmium telluride (CdTe) as a front runner in the field, alongside the more or less stable CIGS/CIS and amorphous silicon technologies. CdTe stands right on top in terms of costs, he said, but there are limitations, such as the rarity of the composition element.

He sees immense promise in dye sensitized solar cells, but so far says it has not broken into the commercial market. Schlock also said that organic photovoltaics has to work towards becoming stable.

In the thin film realm, CIGS is one of the most diversified alternative technologies, with around 30 companies worldwide dabbling in the technology. Schock pointed to the Solar Frontier modules, which at 17 percent efficiency, are "very impressive". However, he sees the efficiency figure climbing to 25 percent in the future. He added that the winning formula will be to choose the technology with the highest efficiency and throughput to place it on the competitive front.

Financing

Amidst all the thin film buzz under the alternatives umbrella, CPVs importance was, as seems to regularly happen, undermined. Patrick McCullough, CFO of Amonix sees investment as the biggest barrier to this technology really taking off on a large scale. "If we start looking at CPV efficiencies, we wonder and go ‘wow’, yet the technology is underutilized," said Nabih.

"Financiers look at CPV as a new technology that is a little volatile. If you look at the money in CPV, it is a little more than one billion USD," added another conference participant. The excitement towards CPV was low, but it has begun to see a change in the last two years.

Lux Research’s Will Polese also agreed that finances are the missing link in alternative solar technologies. "Financing is the most immature link in this industry," he said, bringing forward the fact that demand is present, but the financing mechanism in the photovoltaics sector is retarding growth. Financiers are looking at mainly large scale projects to pump their money into.

CIGS, Polese said, will move to a 2.5 gigawatt business. Banks look for comparisons between possible investments – between a CIGS plant and a gas project, for example – and the lack of standardization of the technologies here leaves a gap. "With standardization, banks can catch up," he concluded.

Scatec Solar chairman, Alf Bjorseth, meanwhile, says he sees crystalline silicon photovoltaic costs reducing and financiers remaining confident, or gaining more confidence in it, because of its impressive track record thus far. Alternatives have some catching up to here.

Dreaming

"If you can dream it, you can do it," Bjorseth said, quoting Walt Disney in his presentation. He looked at the theme of alternatives from a visionary angle, and, after discussing the value chain, posed the question of whether it is possible to produce modules directly from the start, without having to cut the wafers from ingots and waste silicon, and so on.

Bjorseth believes it is possible to cut portions of the value chain out and to tighten the process to a few steps. The same applies for the stabilization and commercial success of technologies in thin film and CPV. These technologies are complicated to adapt with new process step changes. In this sense, crystalline silicon has advantages.

Nabih believes that the time will also come for these "other guy’s in PV". Australia¬ís Martin Green said it is a race, but there is no finishing line. The developments, innovations and changes will keep coming, and step by step improvements will establish a better track record. Then the money will flow confidently into non-crystalline silicon areas of the photovoltaics market, thus thrusting them into the mainstream.