Ausra said Thursday it is building the world's largest factory for solar-thermal power systems in Las Vegas.

The factory, which the company also says is the first solar-thermal manufacturing plant in the United States, is expected to begin operations in April and will be able to produce up to 700 megawatts of solar-thermal equipment annually when it's fully ramped up.

"This one factory will more than double the world output of solar-thermal power capacity," Ausra Vice President John O'Donnell said. "Every year, we can fill 4 square miles with steel, or power half a million homes, from what's built out of this one plant."

A flurry of announcements in the last year, including solar-thermal parks from Israel's Solel Solar Systems and Spain's Acciona Energy, and an announcement Wednesday that a consortium of southwestern states is looking to commission a 250-megawatt plant, indicate the market for a once-staid technology is growing. A report released by Emerging Energy Research on Tuesday forecast that up to $20 billion will be invested in concentrating solar power in the next five years.

"When you add up the global announcements for concentrated solar power, the market is in the thousands of megawatts," said Mike Taylor, a technical-services manager at the Solar Electric Power Association, who cautioned that many plants don't actually operate at their full capacity.

Solar-thermal power plants use the sun's heat, instead of its light, to produce electricity. In Ausra's case, the company is using fields of mirrors to heat water into steam, which can then be converted into electricity using a standard steam turbine.

Instead of expensive parabolic troughs, which are curved mirrors, and pricey evacuated tubes, Ausra's design uses fixed receivers that don't move and cheaper steel-backed troughs.

Taylor said systems such as Ausra's, which use what are called "compact linear Fresnel reflectors" with standard mirrors instead of parabolic troughs, can be less efficient.

"Whether one makes up for the other remains to be seen," he said.

But by replacing hand-built troughs with tractor-truck-sized modules that can be made on a production line and dropped into place with a forklift, Ausra claims its technology can cut solar-thermal costs to 10.4 cents per kilowatt-hour, from an estimated 16 to 18 cents per kilowatt-hour, right away and to 7.9 cents per kilowatt-hour -- less than the cost of coal-fired power -- in three years.

The company, which was founded more than seven years ago as Solar Heat and Power, was reborn as Ausra last year and came out of stealth mode in September. With new executives, $40 million in venture-capital funding and contracts with Pacific Gas & Electric Co. and Florida Light & Power in hand, O'Donnell said the company is now taking its first massive step in executing its business plan.

He said the plant will be able to produce one module, which now takes two hours to make, every 10 minutes. The capacity far exceeds the requirements of the company's contract for a 177-megawatt power plant for PG&E (see Ausra to Build 177-Megawatt Solar-Thermal Plant).

"We're investing early to be the leader," O'Donnell said. "We could produce what's needed for [the PG&E project] in three months, with this factory. And it's going to take three years to build that project, so you can see where we're planning to go."

Ausra wouldn't disclose the price of the factory, but said the plant is already financed with a mixture of equity and debt and that the construction is ready to begin once the company gets building and air permits.

The company also wouldn't disclose the name of the company building the factory, but said it is one of the largest producers of automotive manufacturing lines.

Of course, being first has its risks. Nobody else has built such a large solar-thermal-equipment facility, and scaling up new technologies often comes with unexpected problems.

While Ausra has some secured market from FLP and PG&E, compact linear Fresnel reflector technology "hasn't been scaled up to an actual commercial plant, as far as I know -- only demos," Taylor said.

But O'Donnell said he's not worried.

"We've been manufacturing for three years in Australia; this is really our third line," he said. "There are no new processes or manufacturing risk. All the stuff we're using was developed for use in car manufacturing. We bond steel to glass; car manufacturers do that with windshields. We weld stuff together; they do that too. So it's very similar."

Also, Taylor said Ausra will have to compete against parabolic troughs, and questioned whether -- because of a lack of "real" operating history -- the cost of capital for the company would be higher and the evaluation of its projects would be stricter.

But in spite of challenges, Taylor said the announcement is good for the industry.

"There are supply constraints in parabolic troughs, and the equipment comes from Europe from only a few suppliers, so with the dollar low, that hurts," he said. "Lead times to get equipment are long -- if you order today, you can't get vacuum tubes for over a year and prices have risen 40 percent in the last year. So having a new concentrated solar power technology that can get around these issues can't hurt."