Markus Beck, the chief scientist at Solyndra, has defected to thin-film solar giant First Solar, according to sources.

The departure of Beck is a major loss for Solyndra, according to solar execs who heard about the switch. As chief scientist, Beck oversaw projects for improving the efficiency and performance of the company's unusual, cylindrical copper, indium gallium selenide (CIGS) solar cells. His name is on various Solyndra patents.

"Beck was truly the key technical solar guy over there," wrote one solar exec.

Both Solyndra and First Solar have not returned calls for comment. Rumors of Beck's departure and new home at First Solar began to percolate yesterday afternoon.

The news will likely spark lively gossip and debate in Silicon Valley and the solar world. Like Miasolé and Nanosolar before it, Solyndra has become the CIGS company of the moment. When CIGS comes up as a topic, the conversation very soon begins to revolve around the Fremont, California-based company.

Company backers and executives assert that Solyndra has moved ahead of competitors in the CIGS market. It is in production and, just as important, it has signed multimillion dollar contracts to deliver solar modules to customers. In all, the company has signed deals to deliver around $1.5 billion worth of solar modules to customers between now and 2012.

Detractors, however, paint a different story. Solyndra may have raised over $600 million between 2005 and the middle of 2008, but the last round of financing has been tough. Solyndra started seeking an additional $350 million< ;/a> in the middle of summer. Many VCs said they passed on the deal. On the last day of 2008, Solyndra filed a document with the SEC stating that it had raised approximately $219.2 million.

The company is said to have ove r 400 employees. Even with its supply contracts, though many have speculated that Solyndra will begin to initiate layoffs to cut its costs. Other solar companies like Optisolar have already started mass layoffs. The cylindrical solar cells, some privately say, could also be tough to mass produce.

Sour grapes or a realistic assessment? Only time will tell.

Solyndra has lost top technical talent before. In 2007, Benny Buller, one of the company's founding members and the former vice president of engineering and technology at Solyndra, took off to become director of device improvement at First Solar.

In February 2008, Ratson Morad hit the road to join DayStar Technologies as President and COO. Morad also served as a vice president of engineering and technology and was part of Solyndra's founding team, according to a press release from DayStar.

Jonathan Michael, one of the founders and former CTO of Solyndra, left during the summer of 2008.

Confirming things like layoffs and employment changes is difficult. Founded in 2005, the company largely operated in stealth mode, giving out little about itself other than an address. Details about its patents dribbled out through filings and sources discussed its technology, but the full picture didn't come clear until the press extravaganza in October.

Beck, though, isn't the only high-profile solar star to leave a job recently. Kannan Ramanathan, who served as chief research officer at Miasolé from 2006 to 2008, became a senior researcher at competitor SoloPower last November (see Miasolé's Chief Researcher Defects to SoloPower).

Beck's move will no doubt be cheered by fans of First Solar, which makes cadmium telluride solar cells. Although other companies are getting into its market, First Solar is the only company right now that mass manufactures cadmium telluride solar cells. Besides having something of a de facto monopoly in a technology, First Solar has also relentlessly managed to drop the price of its solar cells through efficient manufacturing. More than anything, the company's ability to exceed forecasts and execute has won admirers. (First Solar's president, Bruce Sohn, came from Intel, which also gets praises for its obsessive manufacturing regimen.)  

Some estimate that energy at some utility scale solar projects using First Solar modules is on par with the cost of coal-fired fuel.