Although still lagging behind crystalline silicon in the maximum efficiency stakes, as costs per Wp fall, thin-film technologies are rapidly taking up a significant share of the PV market. Industry figures give a compound annual growth rate of 60% between 2002 and 2007, and production capacity could reach more than 10 GW in 2010 and 16 GW in 2012. Although uncertainty remains over the timescale, the European Photovoltaic Industry Association (EPIA) nonetheless expects about 4 GW of thin-film production capacity to be operational in 2010. Based mainly in Europe, China, Taiwan, the USA and Japan, this will represent about 20% of total PV module production, up from 10% in 2007.
Consequently, the thin-film sector is considered not only a very dynamic market, but one which also benefits from significant potential for development. Scaling factors, efficiency gains and the new production technologies are expected to reduce thin-film module manufacturing costs to €1/Wp (and below) in the near future, EPIA says. Efficiency is anticipated to rise from a current 6%–12% to 10%–15% in the coming years, with a potential of more than 20% in the longer term. Meanwhile, potential material developments include optimization of different technologies (a-Si, a-Si/µc-Si, CI(G)S and CdTe) in addition to the development of new polymers and other types of organic, dye-sensitive solar cells.
A clear signal of growing confidence in the sector was provided by EPIA’s International Thin Film Conference. Held in November 2008, the event was the first EPIA event to focus on thin-film. With over 350 participants in attendance, the conference, held in Munich, Germany, heard that more than 150 companies had already entered the thin-film business, with some 40 of these already in production.
Winfried Hoffmann, EPIA president, explained that while crystalline silicon module prices have shown a 20% decrease with each doubling of installed capacity, in the case of thin-film modules this digression rate may be higher, especially in the wake of the silicon shortage.
Paula Mints, analyst at Navigant Consulting (and occasional REW contributor), presented analytical data on the evolution of the thin-film PV market, showing a spectacular annual growth rate of 126% in 2007, although she also warned that due to the current global financial environment, growth expectations for the next two to three years need to be reduced slightly.
The subtitle of the conference: ‘Thin Film goes Large!’ seemed particularly appropriate, given that Germany is host to a range of thin-film projects that more than illustrate the technology’s potential. With three new large-scale thin-film PV installations recently commissioned, with a combined capacity of some 50 MW, Germany can provide an excellent insight into the real cut and thrust of the thin-film market.
The future for thin-film
Although there has been a rapid ramp up in the number of companies within the thin-film sector, it’s noteworthy that all three of these projects use modules manufactured by First Solar; speaking at the EPIA thin-film event, that company’s Benny Buller argued that their cadmium telluride (CdTe) modules have the lowest module production cost in the sector, allowing for the lowest module price in the current market. This echoes comments from Mike Ahearn, chairman and CEO of First Solar, who in December said: ’Looking ahead to the next 2-4 years, First Solar will be in a position to produce power from the sun at costs competitive with conventional electricity generated from fossil fuels.’
With a strong policy for cost reduction (glass loss reduction, tellurium cadmium oxide (TCO) loss reduction, low cost encapsulants, faster TCO deposition rates and such like), efficiency increases and economies of scale, in its latest earnings announcement, released in late October, First Solar announced a manufacturing cost of $1.08/W, a figure which includes a $0.04/W ramping up cost associated with factories under construction in Malaysia.
It is clear that with a range of large-scale projects already in operation (where the appropriate support mechanisms are in place), thin-film is rapidly establishing itself as a market force to be reckoned with, both in Germany and around the world. Conference chairman Bernhard Dimmler of Würth Solar GmbH & Co KG summed up the prospects for the technology by asking not if thin-film was competitive with crystalline technologies but rather: ‘Will c-Si be able to compete with thin-film PV in 10 years time?’ He argues that if thin-film PV producers are able to reach their targets, the answer is ‘no’.