The Ivanpah solar power plant in California, which opened Thursday, February 13th, took almost four years and thousands of workers assembling millions of parts to complete. It is the first electric generator of its kind.

Almost 350,000 mirrors the size of garage doors tilt toward the sun with the ability to energize 140,000 homes. Unfortunately, since the beginning of the project, the price of rival technologies has plummeted and incentives have begun to disappear.

“Companies that are supplying these systems have questionable futures. There’s other prospects for renewables and for solar that look a lot better than this particular solution,” he said, including rooftop solar systems that are being installed one by one on businesses and homes.

Many of the executives involved in Ivanpah – a venture among Google, BrightSource Energy, and NRG Energy – say that once this facility proves the technology can work, it will become easier to finance others.

The $1.6 billion federal loan guarantee Ivanpah received during the early days of the Obama administration that financed the project has now ended and the underlying economics shifted during its construction as the price of conventional solar panels dropped.

Still, experts say, BrightSource’s solar thermal technology — which focuses sunlight from mirrors onto 2,200-ton boilers 339 feet in the air to make steam that drives turbines to produce electricity — may have an advantage over conventional panels, which convert sunlight directly into electricity.

Ivanpah’s results will be essential for similar future projects. As for the federal loan guarantee program, the government has already changed its approach and is looking to emphasize a range of cleaner technologies, especially in fossil fuels and nuclear power.