Optisolar, which makes thin-film solar panels and builds large solar farms, has laid off around 300 employees, or half of its staff.

The layoffs come because the company cannot get access to capital, said spokesman Alan Bernheimer. News of the layoffs came today.

"We simply couldn't sustain the level of aggressive growth," he said.

The company has a somewhat unusual structure. It makes amorphous thin-film solar cells and then uses these cells to build utility-scale solar parks. It then sells the electricity from the parks to utilities.

It currently has two large projects on the books: a 210-megawatt plant in Canada for the Ontario Power Authority and a 550-megawatt plant in California for PG&E. These two projects, in fact, are some of the largest photovoltaic projects in the world. (Solar thermal farms are bigger but rely on different technology.

The Canadian project has already begun construction and the California one is slated to begin next year.

The company came seemingly out of nowhere in 2007 but has been growing fast. Governor Arnold Schwarzenegger spoke at the opening of Optisolar's Sacramento-area factory. (Arnold's tour at Optisolar was featured on "60 Minutes"). The company said that the plant would begin to produce solar panels in 2009. When fully built out in 2011, the plant would cover one million square feet, making it one of the largest solar plants in the U.S., Optisolar said back then. The plant would employ 1,000 and pump out 2,000 solar panels a day.

The plant would also qualify the company for up to $20 million in tax breaks. It has raised over $200 million in private equity funding. How did a relatively new and small company score two major deals with established utilities? That question has been asked by many.

The goal was to become as vertically integrated as possible, participating both in the production of panels and the delivery of electricity. That runs counter to the grain of history of the electronics industry, in which companies evolve from being full-service providers to occupying specific niches.

Amorphous silicon panels are less efficient but arguably less challenging to produce than copper indium gallium selenide cells.

Layoffs, though, will be common in solar.

"This is not going to be the only one in the first half," said Rob Day, a principal at venture firm @Ventures.