A major milestone in the start up of Ivanpah, the world's largest solar thermal plant, was reached last Wednesday. At approximately 3:55pm, more than one thousand heliostats focused onto the Ivanpah Unit 1 solar receiver, creating the "first flux."

Solar flux is when a significant amount of sunlight is reflected off of the solar field mirrors.

The flux slowly heated the water inside the boiler to below the point of steam generation. Before today's first flux, the maximum amount of heliostats aimed at the boiler was 5-10 at a time for heliostat calibration (i.e. - inert flux operation).

"First flux is a very important milestone for the project and the solar field team is very proud," said Gil Kroyzer, VP Modeling and Solar Field Design, BrightSource Energy, the technology provider for the Ivanpah project.

"We are now focused on reaching the point where we can place a full load of heliostats onto the boiler and push the project towards commercial operation."

Over the course of the next month, the team will place additional flux on the boiler and begin producing steam to test the steam pressure. When a certain level of pressure is reached, the system will be ready for steam blows to clear out any debris inside the pipes so that it does not damage the steam turbine once operational.

"First flux essentially demonstrates operational readiness of the project" said Mike Bobinecz, VP Construction Management, BrightSource Energy.

"After years of planning, engineering, manufacturing and construction, we are entering the final stage of start-up of the equipment and systems. This represents a great achievement for the project and all of our partners." The 377 MW Ivanpah project is owned by NRG Energy, Google and BrightSource Energy and is being constructed by Bechtel Corporation.

Congratulations to the team on this major accomplishment.