Atmospheric CVD drives CdTe solar ramp
Calyxo is to begin production of CdTe-based solar modules in the first quarter of 2008 using a thin-film technology that could be cheaper than any rival approaches.
The company is using an atmospheric pressure CVD process that it says can be performed without vacuum, keeping costs down and throughput high.
“We see capital expenditure at around €1/W peak - it's quite inexpensive to build capacity, which is important for the overall power generation cost structure,” a spokesperson for the company said.
Rights to the CVD technology now belong to Calyxo after its $5 million buyout of Solar Fields, whose former owners also gain a 7 percent interest in Calyxo. Formerly Calyxo held an exclusive license to use Solar Fields atmospheric-pressure CVD.
The November 1 agreement sees Solar Fields join German silicon photovoltaics giant QCells as a minority partner in Calyxo, while its former Perrysburg, Ohio, operation is renamed Calyxo USA.
Calyxo s currently operational 8 MW development line, which sits just a few hundred meters from QCells main Bitterfeld-Wolfen site in Germany, is being supplemented by a further 25 MW annual production capacity. This plant will ramp-up over summer 2008, but Calyxo seems likely to announce a further expansion even before then.
“We ll be deciding on the next line at the end of this year, something like a 60 MW expansion,” said the company.
The atmospheric-pressure CVD process includes depositing one layer of CdTe and one layer of CdS on a glass substrate, adding contacts and laminating the overall assembly to produce the photovoltaic module.
Using this technology Calyxo has best lab conversion efficiency results of about 16 percent, but is setting its commercial modules the modest target of 7-10 percent.
Solar Fields founder Harold McMaster also established CdTe cell specialist First Solar, which is adding four CdTe production lines to its site in Malaysia. These lines are intended to meet a new $1 billion contract for modules capable of producing 557MW, and are expected to begin production in the second half of 2009.
This recent rapid expansion of CdTe photovoltaic production has bolstered Calyxo s confidence:
“There is an interest in CdTe as you can clearly see from the success First Solar has [had] with its modules,” said Calyxo. “First Solar has shown by bringing out the cheapest modules on the market that this is the right way to go.”
“The Calyxo process has even more benefits because there's no vacuum - that's why we expect such cost reduction potential."
