CdTe gains take heat off TetraSun

Conversion-efficiency improvements made with First Solar’s core Cadmium Telluride (CdTe) thin-film modules have “taken pressure off” the company’s need to rapidly bring its high-efficiency TetraSun modules to market, says chief executive James Hughes.

Last year First Solar acquired California-based startup TetraSun, as concerns grew about the competitive disadvantage of the company’s CdTe modules, which have lower conversion efficiencies than most standard crystalline silicon modules on the market.

First Solar still intends to begin mass production of TetraSun modules in Malaysia later this year, and has a distribution deal in place with JX Nippon in Japan, which is viewed as the core market for TetraSun panels.

But swift gains made recently in First Solar’s CdTe technology may be changing the company’s strategic thinking with regard to TtraSun – or at least its timeframe.

“There is no doubt that the success we’ve had on the [CdTe] front has taken pressure off the need to move TetraSun at a very rapid pace,” Hughes told analysts on Tuesday.

“The distance between the two technologies has unquestionably narrowed, and that takes a little bit of the sense of urgency out of it quite frankly.”

TetraSun modules will still have a “role and opportunity” in “highly space-constrained circumstances or very high [balance of system] circumstances, where their very high efficiencies are worth the incrementally higher costs associated with TetraSun”, Hughes says.

Alongside its second-quarter results, First Solar yesterday announced it has notched up a world-record 21% conversion-efficiency for its CdTe cells in laboratory conditions – leapfrogging rival thin-film technology CIGS, which is often touted as having better long-term potential than CdTe, and is employed at the grandest scale by Japan’s Solar Frontier.

The average conversion efficiency of CdTe modules rolling off First Solar’s production lines during the second quarter was 14%, with its lead line producing at 14.1%.

That represents an efficiency gain of 0.5% in the past quarter alone, First Solar’s largest single-quarter improvement since becoming a public company, according to Hughes.

“To put … this achievement in perspective, [our] total increase in module efficiency last year was 0.5%.”

By the final quarter of 2014, First Solar expects its lead line to be producing modules with a 14.6% efficiency.

“It is this acceleration in efficiency improvements that enables us to begin penetrating space-constrained markets, such as distributed [commercial and industrial], including rooftop,” says Hughes.

First Solar has been touting a metric it calls “energy density” – which amounts to the energy yield per square meter of installed module. In addition to conversion efficiency, energy density also accounts for things like temperate coefficient and shade tolerance, where thin-film modules often have an advantage.

At present, First Solar modules have a 12% disadvantage in energy density against multi-crystalline silicon panels.

But Hughes claims that disadvantage will be trimmed to 5% by the end of 2014, and that sometime next year First Solar’s CdTe modules will boast an energy density advantage against multi-crystalline silicon.